From 8d127aa866a42b36ec6391b025999059dd47cbfd Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:05 +0100 Subject: [PATCH 01/24] Add support for etc/hardware-info fw_cfg file edk2 looks for the etc/hardware-info fw_cfg file to discover hardware which can not easily be found in other ways. Entries consist of a header with hardware type and entry size (HARDWARE_INFO_HEADER), followed by the actual hardware description (which is type specific). The file can have multiple entries. This patch adds the infrastructure to add entries to the file and an entry struct for simple devices (HARDWARE_INFO_SIMPLE_DEVICE) which have an mmio address only. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-2-kraxel@redhat.com> --- hw/uefi/hardware-info.c | 31 +++++++++++++++++++++++++++++ hw/uefi/meson.build | 1 + include/hw/uefi/hardware-info.h | 35 +++++++++++++++++++++++++++++++++ 3 files changed, 67 insertions(+) create mode 100644 hw/uefi/hardware-info.c create mode 100644 hw/uefi/meson.build create mode 100644 include/hw/uefi/hardware-info.h diff --git a/hw/uefi/hardware-info.c b/hw/uefi/hardware-info.c new file mode 100644 index 0000000000..930502a4df --- /dev/null +++ b/hw/uefi/hardware-info.c @@ -0,0 +1,31 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * pass hardware information to uefi + * + * see OvmfPkg/Library/HardwareInfoLib/ in edk2 + */ + +#include "qemu/osdep.h" + +#include "hw/nvram/fw_cfg.h" +#include "hw/uefi/hardware-info.h" + +static void *blob; +static uint64_t blobsize; + +void hardware_info_register(HARDWARE_INFO_TYPE type, void *info, uint64_t infosize) +{ + HARDWARE_INFO_HEADER hdr = { + .type.value = cpu_to_le64(type), + .size = cpu_to_le64(infosize), + }; + + blob = g_realloc(blob, blobsize + sizeof(hdr) + infosize); + memcpy(blob + blobsize, &hdr, sizeof(hdr)); + blobsize += sizeof(hdr); + memcpy(blob + blobsize, info, infosize); + blobsize += infosize; + + fw_cfg_modify_file(fw_cfg_find(), "etc/hardware-info", blob, blobsize); +} diff --git a/hw/uefi/meson.build b/hw/uefi/meson.build new file mode 100644 index 0000000000..a8b1689412 --- /dev/null +++ b/hw/uefi/meson.build @@ -0,0 +1 @@ +system_ss.add(files('hardware-info.c')) diff --git a/include/hw/uefi/hardware-info.h b/include/hw/uefi/hardware-info.h new file mode 100644 index 0000000000..94c38cff20 --- /dev/null +++ b/include/hw/uefi/hardware-info.h @@ -0,0 +1,35 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * pass hardware information to uefi + * + * see OvmfPkg/Library/HardwareInfoLib/ in edk2 + */ +#ifndef QEMU_UEFI_HARDWARE_INFO_H +#define QEMU_UEFI_HARDWARE_INFO_H + +/* data structures */ + +typedef enum { + HardwareInfoTypeUndefined = 0, + HardwareInfoTypeHostBridge = 1, + HardwareInfoQemuUefiVars = 2, +} HARDWARE_INFO_TYPE; + +typedef struct { + union { + uint64_t uint64; + HARDWARE_INFO_TYPE value; + } type; + uint64_t size; +} HARDWARE_INFO_HEADER; + +typedef struct { + uint64_t mmio_address; +} HARDWARE_INFO_SIMPLE_DEVICE; + +/* qemu functions */ + +void hardware_info_register(HARDWARE_INFO_TYPE type, void *info, uint64_t size); + +#endif /* QEMU_UEFI_HARDWARE_INFO_H */ From 995496fd216a6bf6f709c52992c0c423565a63b7 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:06 +0100 Subject: [PATCH 02/24] hw/uefi: add include/hw/uefi/var-service-api.h This file defines the register interface of the uefi-vars device. It's only a handful of registers: magic value, command and status registers, location and size of the communication buffer. Reviewed-by: Laszlo Ersek Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-3-kraxel@redhat.com> --- include/hw/uefi/var-service-api.h | 48 +++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 include/hw/uefi/var-service-api.h diff --git a/include/hw/uefi/var-service-api.h b/include/hw/uefi/var-service-api.h new file mode 100644 index 0000000000..0d71638f3e --- /dev/null +++ b/include/hw/uefi/var-service-api.h @@ -0,0 +1,48 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi-vars device - API of the virtual device for guest/host communication. + */ +#ifndef QEMU_UEFI_VAR_SERVICE_API_H +#define QEMU_UEFI_VAR_SERVICE_API_H + +/* qom: device names */ +#define TYPE_UEFI_VARS_X64 "uefi-vars-x64" +#define TYPE_UEFI_VARS_SYSBUS "uefi-vars-sysbus" + +/* sysbus: fdt node path */ +#define UEFI_VARS_FDT_NODE "qemu-uefi-vars" +#define UEFI_VARS_FDT_COMPAT "qemu,uefi-vars" + +/* registers */ +#define UEFI_VARS_REG_MAGIC 0x00 /* 16 bit */ +#define UEFI_VARS_REG_CMD_STS 0x02 /* 16 bit */ +#define UEFI_VARS_REG_BUFFER_SIZE 0x04 /* 32 bit */ +#define UEFI_VARS_REG_DMA_BUFFER_ADDR_LO 0x08 /* 32 bit */ +#define UEFI_VARS_REG_DMA_BUFFER_ADDR_HI 0x0c /* 32 bit */ +#define UEFI_VARS_REG_PIO_BUFFER_TRANSFER 0x10 /* 8-64 bit */ +#define UEFI_VARS_REG_PIO_BUFFER_CRC32C 0x18 /* 32 bit (read-only) */ +#define UEFI_VARS_REG_FLAGS 0x1c /* 32 bit */ +#define UEFI_VARS_REGS_SIZE 0x20 + +/* flags register */ +#define UEFI_VARS_FLAG_USE_PIO (1 << 0) + +/* magic value */ +#define UEFI_VARS_MAGIC_VALUE 0xef1 + +/* command values */ +#define UEFI_VARS_CMD_RESET 0x01 +#define UEFI_VARS_CMD_DMA_MM 0x02 +#define UEFI_VARS_CMD_PIO_MM 0x03 +#define UEFI_VARS_CMD_PIO_ZERO_OFFSET 0x04 + +/* status values */ +#define UEFI_VARS_STS_SUCCESS 0x00 +#define UEFI_VARS_STS_BUSY 0x01 +#define UEFI_VARS_STS_ERR_UNKNOWN 0x10 +#define UEFI_VARS_STS_ERR_NOT_SUPPORTED 0x11 +#define UEFI_VARS_STS_ERR_BAD_BUFFER_SIZE 0x12 + + +#endif /* QEMU_UEFI_VAR_SERVICE_API_H */ From 8614eb902b1a63e837e5a8fd871b8c64e700d46f Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:07 +0100 Subject: [PATCH 03/24] hw/uefi: add include/hw/uefi/var-service-edk2.h A bunch of #defines and structs copied over from edk2, mostly needed to decode and encode the messages in the communication buffer. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-4-kraxel@redhat.com> --- include/hw/uefi/var-service-edk2.h | 227 +++++++++++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 include/hw/uefi/var-service-edk2.h diff --git a/include/hw/uefi/var-service-edk2.h b/include/hw/uefi/var-service-edk2.h new file mode 100644 index 0000000000..c743a8df94 --- /dev/null +++ b/include/hw/uefi/var-service-edk2.h @@ -0,0 +1,227 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi-vars device - structs and defines from edk2 + * + * Note: The edk2 UINTN type has been mapped to uint64_t, + * so the structs are compatible with 64bit edk2 builds. + */ +#ifndef QEMU_UEFI_VAR_SERVICE_EDK2_H +#define QEMU_UEFI_VAR_SERVICE_EDK2_H + +#include "qemu/uuid.h" + +#define MAX_BIT 0x8000000000000000ULL +#define ENCODE_ERROR(StatusCode) (MAX_BIT | (StatusCode)) +#define EFI_SUCCESS 0 +#define EFI_INVALID_PARAMETER ENCODE_ERROR(2) +#define EFI_UNSUPPORTED ENCODE_ERROR(3) +#define EFI_BAD_BUFFER_SIZE ENCODE_ERROR(4) +#define EFI_BUFFER_TOO_SMALL ENCODE_ERROR(5) +#define EFI_WRITE_PROTECTED ENCODE_ERROR(8) +#define EFI_OUT_OF_RESOURCES ENCODE_ERROR(9) +#define EFI_NOT_FOUND ENCODE_ERROR(14) +#define EFI_ACCESS_DENIED ENCODE_ERROR(15) +#define EFI_ALREADY_STARTED ENCODE_ERROR(20) +#define EFI_SECURITY_VIOLATION ENCODE_ERROR(26) + +#define EFI_VARIABLE_NON_VOLATILE 0x01 +#define EFI_VARIABLE_BOOTSERVICE_ACCESS 0x02 +#define EFI_VARIABLE_RUNTIME_ACCESS 0x04 +#define EFI_VARIABLE_HARDWARE_ERROR_RECORD 0x08 +#define EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS 0x10 /* deprecated */ +#define EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS 0x20 +#define EFI_VARIABLE_APPEND_WRITE 0x40 + +/* SecureBootEnable */ +#define SECURE_BOOT_ENABLE 1 +#define SECURE_BOOT_DISABLE 0 + +/* SecureBoot */ +#define SECURE_BOOT_MODE_ENABLE 1 +#define SECURE_BOOT_MODE_DISABLE 0 + +/* CustomMode */ +#define CUSTOM_SECURE_BOOT_MODE 1 +#define STANDARD_SECURE_BOOT_MODE 0 + +/* SetupMode */ +#define SETUP_MODE 1 +#define USER_MODE 0 + +typedef uint64_t efi_status; +typedef struct mm_header mm_header; + +/* EFI_MM_COMMUNICATE_HEADER */ +struct mm_header { + QemuUUID guid; + uint64_t length; +}; + +/* --- EfiSmmVariableProtocol ---------------------------------------- */ + +#define SMM_VARIABLE_FUNCTION_GET_VARIABLE 1 +#define SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME 2 +#define SMM_VARIABLE_FUNCTION_SET_VARIABLE 3 +#define SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO 4 +#define SMM_VARIABLE_FUNCTION_READY_TO_BOOT 5 +#define SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE 6 +#define SMM_VARIABLE_FUNCTION_LOCK_VARIABLE 8 +#define SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE 11 + +typedef struct mm_variable mm_variable; +typedef struct mm_variable_access mm_variable_access; +typedef struct mm_next_variable mm_next_variable; +typedef struct mm_next_variable mm_lock_variable; +typedef struct mm_variable_info mm_variable_info; +typedef struct mm_get_payload_size mm_get_payload_size; + +/* SMM_VARIABLE_COMMUNICATE_HEADER */ +struct mm_variable { + uint64_t function; + uint64_t status; +}; + +/* SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE */ +struct QEMU_PACKED mm_variable_access { + QemuUUID guid; + uint64_t data_size; + uint64_t name_size; + uint32_t attributes; + /* Name */ + /* Data */ +}; + +/* SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME */ +struct mm_next_variable { + QemuUUID guid; + uint64_t name_size; + /* Name */ +}; + +/* SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO */ +struct QEMU_PACKED mm_variable_info { + uint64_t max_storage_size; + uint64_t free_storage_size; + uint64_t max_variable_size; + uint32_t attributes; +}; + +/* SMM_VARIABLE_COMMUNICATE_GET_PAYLOAD_SIZE */ +struct mm_get_payload_size { + uint64_t payload_size; +}; + +/* --- VarCheckPolicyLibMmiHandler ----------------------------------- */ + +#define VAR_CHECK_POLICY_COMMAND_DISABLE 0x01 +#define VAR_CHECK_POLICY_COMMAND_IS_ENABLED 0x02 +#define VAR_CHECK_POLICY_COMMAND_REGISTER 0x03 +#define VAR_CHECK_POLICY_COMMAND_DUMP 0x04 +#define VAR_CHECK_POLICY_COMMAND_LOCK 0x05 + +typedef struct mm_check_policy mm_check_policy; +typedef struct mm_check_policy_is_enabled mm_check_policy_is_enabled; +typedef struct mm_check_policy_dump_params mm_check_policy_dump_params; + +/* VAR_CHECK_POLICY_COMM_HEADER */ +struct QEMU_PACKED mm_check_policy { + uint32_t signature; + uint32_t revision; + uint32_t command; + uint64_t result; +}; + +/* VAR_CHECK_POLICY_COMM_IS_ENABLED_PARAMS */ +struct QEMU_PACKED mm_check_policy_is_enabled { + uint8_t state; +}; + +/* VAR_CHECK_POLICY_COMM_DUMP_PARAMS */ +struct QEMU_PACKED mm_check_policy_dump_params { + uint32_t page_requested; + uint32_t total_size; + uint32_t page_size; + uint8_t has_more; +}; + +/* --- Edk2VariablePolicyProtocol ------------------------------------ */ + +#define VARIABLE_POLICY_ENTRY_REVISION 0x00010000 + +#define VARIABLE_POLICY_TYPE_NO_LOCK 0 +#define VARIABLE_POLICY_TYPE_LOCK_NOW 1 +#define VARIABLE_POLICY_TYPE_LOCK_ON_CREATE 2 +#define VARIABLE_POLICY_TYPE_LOCK_ON_VAR_STATE 3 + +typedef struct variable_policy_entry variable_policy_entry; +typedef struct variable_lock_on_var_state variable_lock_on_var_state; + +/* VARIABLE_POLICY_ENTRY */ +struct variable_policy_entry { + uint32_t version; + uint16_t size; + uint16_t offset_to_name; + QemuUUID namespace; + uint32_t min_size; + uint32_t max_size; + uint32_t attributes_must_have; + uint32_t attributes_cant_have; + uint8_t lock_policy_type; + uint8_t padding[3]; + /* LockPolicy */ + /* Name */ +}; + +/* VARIABLE_LOCK_ON_VAR_STATE_POLICY */ +struct variable_lock_on_var_state { + QemuUUID namespace; + uint8_t value; + uint8_t padding; + /* Name */ +}; + +/* --- variable authentication --------------------------------------- */ + +#define WIN_CERT_TYPE_EFI_GUID 0x0EF1 + +typedef struct efi_time efi_time; +typedef struct efi_siglist efi_siglist; +typedef struct variable_auth_2 variable_auth_2; + +/* EFI_TIME */ +struct efi_time { + uint16_t year; + uint8_t month; + uint8_t day; + uint8_t hour; + uint8_t minute; + uint8_t second; + uint8_t pad1; + uint32_t nanosecond; + int16_t timezone; + uint8_t daylight; + uint8_t pad2; +}; + +/* EFI_SIGNATURE_LIST */ +struct efi_siglist { + QemuUUID guid_type; + uint32_t siglist_size; + uint32_t header_size; + uint32_t sig_size; +}; + +/* EFI_VARIABLE_AUTHENTICATION_2 */ +struct variable_auth_2 { + struct efi_time timestamp; + + /* WIN_CERTIFICATE_UEFI_GUID */ + uint32_t hdr_length; + uint16_t hdr_revision; + uint16_t hdr_cert_type; + QemuUUID guid_cert_type; + uint8_t cert_data[]; +}; + +#endif /* QEMU_UEFI_VAR_SERVICE_EDK2_H */ From 8b7ed5845cec8d4308707e53469d328b6ad0d9ed Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:08 +0100 Subject: [PATCH 04/24] hw/uefi: add include/hw/uefi/var-service.h Add state structs and function declarations for the uefi-vars device. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-5-kraxel@redhat.com> --- include/hw/uefi/var-service.h | 191 ++++++++++++++++++++++++++++++++++ 1 file changed, 191 insertions(+) create mode 100644 include/hw/uefi/var-service.h diff --git a/include/hw/uefi/var-service.h b/include/hw/uefi/var-service.h new file mode 100644 index 0000000000..f7ceac4ce2 --- /dev/null +++ b/include/hw/uefi/var-service.h @@ -0,0 +1,191 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi-vars device - state struct and function prototypes + */ +#ifndef QEMU_UEFI_VAR_SERVICE_H +#define QEMU_UEFI_VAR_SERVICE_H + +#include "qemu/uuid.h" +#include "qemu/queue.h" + +#include "hw/uefi/var-service-edk2.h" + +#define MAX_BUFFER_SIZE (64 * 1024) + +typedef struct uefi_variable uefi_variable; +typedef struct uefi_var_policy uefi_var_policy; +typedef struct uefi_vars_state uefi_vars_state; + +typedef struct uefi_vars_cert uefi_vars_cert; +typedef struct uefi_vars_hash uefi_vars_hash; +typedef struct uefi_vars_siglist uefi_vars_siglist; + +struct uefi_variable { + QemuUUID guid; + uint16_t *name; + uint32_t name_size; + uint32_t attributes; + void *data; + uint32_t data_size; + efi_time time; + void *digest; + uint32_t digest_size; + QTAILQ_ENTRY(uefi_variable) next; +}; + +struct uefi_var_policy { + variable_policy_entry *entry; + uint32_t entry_size; + uint16_t *name; + uint32_t name_size; + + /* number of hashmarks (wildcard character) in name */ + uint32_t hashmarks; + + QTAILQ_ENTRY(uefi_var_policy) next; +}; + +struct uefi_vars_state { + MemoryRegion mr; + uint16_t sts; + uint32_t buf_size; + uint32_t buf_addr_lo; + uint32_t buf_addr_hi; + uint8_t *buffer; + QTAILQ_HEAD(, uefi_variable) variables; + QTAILQ_HEAD(, uefi_var_policy) var_policies; + + /* pio transfer buffer */ + uint32_t pio_xfer_offset; + uint8_t *pio_xfer_buffer; + + /* boot phases */ + bool end_of_dxe; + bool ready_to_boot; + bool exit_boot_service; + bool policy_locked; + + /* storage accounting */ + uint64_t max_storage; + uint64_t used_storage; + + /* config options */ + char *jsonfile; + int jsonfd; + bool force_secure_boot; + bool disable_custom_mode; + bool use_pio; +}; + +struct uefi_vars_cert { + QTAILQ_ENTRY(uefi_vars_cert) next; + QemuUUID owner; + uint64_t size; + uint8_t data[]; +}; + +struct uefi_vars_hash { + QTAILQ_ENTRY(uefi_vars_hash) next; + QemuUUID owner; + uint8_t data[]; +}; + +struct uefi_vars_siglist { + QTAILQ_HEAD(, uefi_vars_cert) x509; + QTAILQ_HEAD(, uefi_vars_hash) sha256; +}; + +/* vars-service-guid.c */ +extern const QemuUUID EfiGlobalVariable; +extern const QemuUUID EfiImageSecurityDatabase; +extern const QemuUUID EfiCustomModeEnable; +extern const QemuUUID EfiSecureBootEnableDisable; + +extern const QemuUUID EfiCertSha256Guid; +extern const QemuUUID EfiCertSha384Guid; +extern const QemuUUID EfiCertSha512Guid; +extern const QemuUUID EfiCertRsa2048Guid; +extern const QemuUUID EfiCertX509Guid; +extern const QemuUUID EfiCertTypePkcs7Guid; + +extern const QemuUUID EfiSmmVariableProtocolGuid; +extern const QemuUUID VarCheckPolicyLibMmiHandlerGuid; + +extern const QemuUUID EfiEndOfDxeEventGroupGuid; +extern const QemuUUID EfiEventReadyToBootGuid; +extern const QemuUUID EfiEventExitBootServicesGuid; + +/* vars-service-utils.c */ +gboolean uefi_str_is_valid(const uint16_t *str, size_t len, + gboolean must_be_null_terminated); +size_t uefi_strlen(const uint16_t *str, size_t len); +gboolean uefi_str_equal_ex(const uint16_t *a, size_t alen, + const uint16_t *b, size_t blen, + gboolean wildcards_in_a); +gboolean uefi_str_equal(const uint16_t *a, size_t alen, + const uint16_t *b, size_t blen); +char *uefi_ucs2_to_ascii(const uint16_t *ucs2, uint64_t ucs2_size); +int uefi_time_compare(efi_time *a, efi_time *b); +void uefi_trace_variable(const char *action, QemuUUID guid, + const uint16_t *name, uint64_t name_size); +void uefi_trace_status(const char *action, efi_status status); + +/* vars-service-core.c */ +extern const VMStateDescription vmstate_uefi_vars; +void uefi_vars_init(Object *obj, uefi_vars_state *uv); +void uefi_vars_realize(uefi_vars_state *uv, Error **errp); +void uefi_vars_hard_reset(uefi_vars_state *uv); + +/* vars-service-json.c */ +void uefi_vars_json_init(uefi_vars_state *uv, Error **errp); +void uefi_vars_json_save(uefi_vars_state *uv); +void uefi_vars_json_load(uefi_vars_state *uv, Error **errp); + +/* vars-service-vars.c */ +extern const VMStateDescription vmstate_uefi_variable; +uefi_variable *uefi_vars_find_variable(uefi_vars_state *uv, QemuUUID guid, + const uint16_t *name, + uint64_t name_size); +void uefi_vars_set_variable(uefi_vars_state *uv, QemuUUID guid, + const uint16_t *name, uint64_t name_size, + uint32_t attributes, + void *data, uint64_t data_size); +void uefi_vars_clear_volatile(uefi_vars_state *uv); +void uefi_vars_clear_all(uefi_vars_state *uv); +void uefi_vars_update_storage(uefi_vars_state *uv); +uint32_t uefi_vars_mm_vars_proto(uefi_vars_state *uv); + +/* vars-service-auth.c */ +bool uefi_vars_is_sb_pk(uefi_variable *var); +bool uefi_vars_is_sb_any(uefi_variable *var); +efi_status uefi_vars_check_auth_2(uefi_vars_state *uv, uefi_variable *var, + mm_variable_access *va, void *data); +efi_status uefi_vars_check_secure_boot(uefi_vars_state *uv, uefi_variable *var); +void uefi_vars_auth_init(uefi_vars_state *uv); + +/* vars-service-pkcs7.c */ +efi_status uefi_vars_check_pkcs7_2(uefi_variable *siglist, + void **digest, uint32_t *digest_size, + mm_variable_access *va, void *data); + +/* vars-service-siglist.c */ +void uefi_vars_siglist_init(uefi_vars_siglist *siglist); +void uefi_vars_siglist_free(uefi_vars_siglist *siglist); +void uefi_vars_siglist_parse(uefi_vars_siglist *siglist, + void *data, uint64_t size); +uint64_t uefi_vars_siglist_blob_size(uefi_vars_siglist *siglist); +void uefi_vars_siglist_blob_generate(uefi_vars_siglist *siglist, + void *data, uint64_t size); + +/* vars-service-policy.c */ +extern const VMStateDescription vmstate_uefi_var_policy; +efi_status uefi_vars_policy_check(uefi_vars_state *uv, + uefi_variable *var, + gboolean is_newvar); +void uefi_vars_policies_clear(uefi_vars_state *uv); +uefi_var_policy *uefi_vars_add_policy(uefi_vars_state *uv, + variable_policy_entry *pe); +uint32_t uefi_vars_mm_check_policy_proto(uefi_vars_state *uv); + +#endif /* QEMU_UEFI_VAR_SERVICE_H */ From 231b6c9ee8d4cf4ebaae4e4da31ff73c2ec8e6e9 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:09 +0100 Subject: [PATCH 05/24] hw/uefi: add var-service-guid.c Add variables for a bunch of UEFI GUIDs we will need. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-6-kraxel@redhat.com> --- hw/uefi/var-service-guid.c | 99 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) create mode 100644 hw/uefi/var-service-guid.c diff --git a/hw/uefi/var-service-guid.c b/hw/uefi/var-service-guid.c new file mode 100644 index 0000000000..eba3655c8d --- /dev/null +++ b/hw/uefi/var-service-guid.c @@ -0,0 +1,99 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - GUIDs + */ + +#include "qemu/osdep.h" +#include "system/dma.h" + +#include "hw/uefi/var-service.h" + +/* variable namespaces */ + +const QemuUUID EfiGlobalVariable = { + .data = UUID_LE(0x8be4df61, 0x93ca, 0x11d2, 0xaa, 0x0d, + 0x00, 0xe0, 0x98, 0x03, 0x2b, 0x8c) +}; + +const QemuUUID EfiImageSecurityDatabase = { + .data = UUID_LE(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, + 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) +}; + +const QemuUUID EfiCustomModeEnable = { + .data = UUID_LE(0xc076ec0c, 0x7028, 0x4399, 0xa0, 0x72, + 0x71, 0xee, 0x5c, 0x44, 0x8b, 0x9f) +}; + +const QemuUUID EfiSecureBootEnableDisable = { + .data = UUID_LE(0xf0a30bc7, 0xaf08, 0x4556, 0x99, 0xc4, + 0x0, 0x10, 0x9, 0xc9, 0x3a, 0x44) +}; + +/* signatures */ + +const QemuUUID EfiCertSha256Guid = { + .data = UUID_LE(0xc1c41626, 0x504c, 0x4092, 0xac, 0xa9, + 0x41, 0xf9, 0x36, 0x93, 0x43, 0x28) +}; + +const QemuUUID EfiCertSha384Guid = { + .data = UUID_LE(0xff3e5307, 0x9fd0, 0x48c9, 0x85, 0xf1, + 0x8a, 0xd5, 0x6c, 0x70, 0x1e, 0x1) +}; + +const QemuUUID EfiCertSha512Guid = { + .data = UUID_LE(0x93e0fae, 0xa6c4, 0x4f50, 0x9f, 0x1b, + 0xd4, 0x1e, 0x2b, 0x89, 0xc1, 0x9a) +}; + +const QemuUUID EfiCertRsa2048Guid = { + .data = UUID_LE(0x3c5766e8, 0x269c, 0x4e34, 0xaa, 0x14, + 0xed, 0x77, 0x6e, 0x85, 0xb3, 0xb6) +}; + +const QemuUUID EfiCertX509Guid = { + .data = UUID_LE(0xa5c059a1, 0x94e4, 0x4aa7, 0x87, 0xb5, + 0xab, 0x15, 0x5c, 0x2b, 0xf0, 0x72) +}; + +const QemuUUID EfiCertTypePkcs7Guid = { + .data = UUID_LE(0x4aafd29d, 0x68df, 0x49ee, 0x8a, 0xa9, + 0x34, 0x7d, 0x37, 0x56, 0x65, 0xa7) +}; + +/* + * mm_header.guid values that the guest DXE/BDS phases use for + * sending requests to management mode + */ + +const QemuUUID EfiSmmVariableProtocolGuid = { + .data = UUID_LE(0xed32d533, 0x99e6, 0x4209, 0x9c, 0xc0, + 0x2d, 0x72, 0xcd, 0xd9, 0x98, 0xa7) +}; + +const QemuUUID VarCheckPolicyLibMmiHandlerGuid = { + .data = UUID_LE(0xda1b0d11, 0xd1a7, 0x46c4, 0x9d, 0xc9, + 0xf3, 0x71, 0x48, 0x75, 0xc6, 0xeb) +}; + +/* + * mm_header.guid values that the guest DXE/BDS phases use for + * reporting event groups being signaled to management mode + */ + +const QemuUUID EfiEndOfDxeEventGroupGuid = { + .data = UUID_LE(0x02ce967a, 0xdd7e, 0x4FFc, 0x9e, 0xe7, + 0x81, 0x0c, 0xF0, 0x47, 0x08, 0x80) +}; + +const QemuUUID EfiEventReadyToBootGuid = { + .data = UUID_LE(0x7ce88Fb3, 0x4bd7, 0x4679, 0x87, 0xa8, + 0xa8, 0xd8, 0xde, 0xe5, 0x0d, 0x2b) +}; + +const QemuUUID EfiEventExitBootServicesGuid = { + .data = UUID_LE(0x27abF055, 0xb1b8, 0x4c26, 0x80, 0x48, + 0x74, 0x8F, 0x37, 0xba, 0xa2, 0xdF) +}; From 1ebc319c8ca7ad8af350026662ae18fdcb8b0dac Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:10 +0100 Subject: [PATCH 06/24] hw/uefi: add var-service-utils.c Add utility functions. Helpers for UEFI (ucs2) string handling. Helpers for readable trace messages. Compare UEFI time stamps. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-7-kraxel@redhat.com> --- hw/uefi/var-service-utils.c | 241 ++++++++++++++++++++++++++++++++++++ 1 file changed, 241 insertions(+) create mode 100644 hw/uefi/var-service-utils.c diff --git a/hw/uefi/var-service-utils.c b/hw/uefi/var-service-utils.c new file mode 100644 index 0000000000..c9ef46570f --- /dev/null +++ b/hw/uefi/var-service-utils.c @@ -0,0 +1,241 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - helper functions for ucs2 strings and tracing + */ +#include "qemu/osdep.h" +#include "system/dma.h" + +#include "hw/uefi/var-service.h" + +#include "trace/trace-hw_uefi.h" + +/* ------------------------------------------------------------------ */ + +/* + * string helper functions. + * + * Most of the time uefi ucs2 strings are NULL-terminated, except + * sometimes when they are not (for example in variable policies). + */ + +gboolean uefi_str_is_valid(const uint16_t *str, size_t len, + gboolean must_be_null_terminated) +{ + size_t pos = 0; + + for (;;) { + if (pos == len) { + if (must_be_null_terminated) { + return false; + } else { + return true; + } + } + switch (str[pos]) { + case 0: + /* end of string */ + return true; + case 0xd800 ... 0xdfff: + /* reject surrogates */ + return false; + default: + /* char is good, check next */ + break; + } + pos++; + } +} + +size_t uefi_strlen(const uint16_t *str, size_t len) +{ + size_t pos = 0; + + for (;;) { + if (pos == len) { + return pos; + } + if (str[pos] == 0) { + return pos; + } + pos++; + } +} + +gboolean uefi_str_equal_ex(const uint16_t *a, size_t alen, + const uint16_t *b, size_t blen, + gboolean wildcards_in_a) +{ + size_t pos = 0; + + alen = alen / 2; + blen = blen / 2; + for (;;) { + if (pos == alen && pos == blen) { + return true; + } + if (pos == alen && b[pos] == 0) { + return true; + } + if (pos == blen && a[pos] == 0) { + return true; + } + if (pos == alen || pos == blen) { + return false; + } + if (a[pos] == 0 && b[pos] == 0) { + return true; + } + + if (wildcards_in_a && a[pos] == '#') { + if (!isxdigit(b[pos])) { + return false; + } + } else { + if (a[pos] != b[pos]) { + return false; + } + } + pos++; + } +} + +gboolean uefi_str_equal(const uint16_t *a, size_t alen, + const uint16_t *b, size_t blen) +{ + return uefi_str_equal_ex(a, alen, b, blen, false); +} + +char *uefi_ucs2_to_ascii(const uint16_t *ucs2, uint64_t ucs2_size) +{ + char *str = g_malloc0(ucs2_size / 2 + 1); + int i; + + for (i = 0; i * 2 < ucs2_size; i++) { + if (ucs2[i] == 0) { + break; + } + if (ucs2[i] < 128) { + str[i] = ucs2[i]; + } else { + str[i] = '?'; + } + } + str[i] = 0; + return str; +} + +/* ------------------------------------------------------------------ */ +/* time helper functions */ + +int uefi_time_compare(efi_time *a, efi_time *b) +{ + if (a->year < b->year) { + return -1; + } + if (a->year > b->year) { + return 1; + } + + if (a->month < b->month) { + return -1; + } + if (a->month > b->month) { + return 1; + } + + if (a->day < b->day) { + return -1; + } + if (a->day > b->day) { + return 1; + } + + if (a->hour < b->hour) { + return -1; + } + if (a->hour > b->hour) { + return 1; + } + + if (a->minute < b->minute) { + return -1; + } + if (a->minute > b->minute) { + return 1; + } + + if (a->second < b->second) { + return -1; + } + if (a->second > b->second) { + return 1; + } + + if (a->nanosecond < b->nanosecond) { + return -1; + } + if (a->nanosecond > b->nanosecond) { + return 1; + } + + return 0; +} + +/* ------------------------------------------------------------------ */ +/* tracing helper functions */ + +void uefi_trace_variable(const char *action, QemuUUID guid, + const uint16_t *name, uint64_t name_size) +{ + QemuUUID be = qemu_uuid_bswap(guid); + char *str_uuid = qemu_uuid_unparse_strdup(&be); + char *str_name = uefi_ucs2_to_ascii(name, name_size); + + trace_uefi_variable(action, str_name, name_size, str_uuid); + + g_free(str_name); + g_free(str_uuid); +} + +void uefi_trace_status(const char *action, efi_status status) +{ + switch (status) { + case EFI_SUCCESS: + trace_uefi_status(action, "success"); + break; + case EFI_INVALID_PARAMETER: + trace_uefi_status(action, "invalid parameter"); + break; + case EFI_UNSUPPORTED: + trace_uefi_status(action, "unsupported"); + break; + case EFI_BAD_BUFFER_SIZE: + trace_uefi_status(action, "bad buffer size"); + break; + case EFI_BUFFER_TOO_SMALL: + trace_uefi_status(action, "buffer too small"); + break; + case EFI_WRITE_PROTECTED: + trace_uefi_status(action, "write protected"); + break; + case EFI_OUT_OF_RESOURCES: + trace_uefi_status(action, "out of resources"); + break; + case EFI_NOT_FOUND: + trace_uefi_status(action, "not found"); + break; + case EFI_ACCESS_DENIED: + trace_uefi_status(action, "access denied"); + break; + case EFI_ALREADY_STARTED: + trace_uefi_status(action, "already started"); + break; + case EFI_SECURITY_VIOLATION: + trace_uefi_status(action, "security violation"); + break; + default: + trace_uefi_status(action, "unknown error"); + break; + } +} From db1ecfb473ac58f2bd065ca6f2a50c6294ff9169 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:11 +0100 Subject: [PATCH 07/24] hw/uefi: add var-service-vars.c This is the uefi variable service (EfiSmmVariableProtocol), providing functions for listing, reading and updating variables. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-8-kraxel@redhat.com> --- hw/uefi/var-service-vars.c | 725 +++++++++++++++++++++++++++++++++++++ 1 file changed, 725 insertions(+) create mode 100644 hw/uefi/var-service-vars.c diff --git a/hw/uefi/var-service-vars.c b/hw/uefi/var-service-vars.c new file mode 100644 index 0000000000..7f98d77a38 --- /dev/null +++ b/hw/uefi/var-service-vars.c @@ -0,0 +1,725 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - EfiSmmVariableProtocol implementation + */ +#include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "system/dma.h" +#include "migration/vmstate.h" + +#include "hw/uefi/var-service.h" +#include "hw/uefi/var-service-api.h" +#include "hw/uefi/var-service-edk2.h" + +#include "trace/trace-hw_uefi.h" + +#define EFI_VARIABLE_ATTRIBUTE_SUPPORTED \ + (EFI_VARIABLE_NON_VOLATILE | \ + EFI_VARIABLE_BOOTSERVICE_ACCESS | \ + EFI_VARIABLE_RUNTIME_ACCESS | \ + EFI_VARIABLE_HARDWARE_ERROR_RECORD | \ + EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS | \ + EFI_VARIABLE_APPEND_WRITE) + + +const VMStateDescription vmstate_uefi_time = { + .name = "uefi-time", + .fields = (VMStateField[]) { + VMSTATE_UINT16(year, efi_time), + VMSTATE_UINT8(month, efi_time), + VMSTATE_UINT8(day, efi_time), + VMSTATE_UINT8(hour, efi_time), + VMSTATE_UINT8(minute, efi_time), + VMSTATE_UINT8(second, efi_time), + VMSTATE_UINT32(nanosecond, efi_time), + VMSTATE_END_OF_LIST() + }, +}; + +const VMStateDescription vmstate_uefi_variable = { + .name = "uefi-variable", + .fields = (VMStateField[]) { + VMSTATE_UINT8_ARRAY_V(guid.data, uefi_variable, sizeof(QemuUUID), 0), + VMSTATE_UINT32(name_size, uefi_variable), + VMSTATE_UINT32(data_size, uefi_variable), + VMSTATE_UINT32(attributes, uefi_variable), + VMSTATE_VBUFFER_ALLOC_UINT32(name, uefi_variable, 0, NULL, name_size), + VMSTATE_VBUFFER_ALLOC_UINT32(data, uefi_variable, 0, NULL, data_size), + VMSTATE_STRUCT(time, uefi_variable, 0, vmstate_uefi_time, efi_time), + VMSTATE_END_OF_LIST() + }, +}; + +uefi_variable *uefi_vars_find_variable(uefi_vars_state *uv, QemuUUID guid, + const uint16_t *name, uint64_t name_size) +{ + uefi_variable *var; + + QTAILQ_FOREACH(var, &uv->variables, next) { + if (!uefi_str_equal(var->name, var->name_size, + name, name_size)) { + continue; + } + if (!qemu_uuid_is_equal(&var->guid, &guid)) { + continue; + } + if (!var->data_size) { + /* in process of being created/updated */ + continue; + } + return var; + } + return NULL; +} + +static uefi_variable *add_variable(uefi_vars_state *uv, QemuUUID guid, + const uint16_t *name, uint64_t name_size, + uint32_t attributes) +{ + uefi_variable *var; + + var = g_new0(uefi_variable, 1); + var->guid = guid; + var->name = g_malloc(name_size); + memcpy(var->name, name, name_size); + var->name_size = name_size; + var->attributes = attributes; + + var->attributes &= ~EFI_VARIABLE_APPEND_WRITE; + + QTAILQ_INSERT_TAIL(&uv->variables, var, next); + return var; +} + +static void del_variable(uefi_vars_state *uv, uefi_variable *var) +{ + if (!var) { + return; + } + + QTAILQ_REMOVE(&uv->variables, var, next); + g_free(var->data); + g_free(var->name); + g_free(var->digest); + g_free(var); +} + +static size_t variable_size(uefi_variable *var) +{ + size_t size; + + size = sizeof(*var); + size += var->name_size; + size += var->data_size; + size += var->digest_size; + return size; +} + +void uefi_vars_set_variable(uefi_vars_state *uv, QemuUUID guid, + const uint16_t *name, uint64_t name_size, + uint32_t attributes, + void *data, uint64_t data_size) +{ + uefi_variable *old_var, *new_var; + + uefi_trace_variable(__func__, guid, name, name_size); + + old_var = uefi_vars_find_variable(uv, guid, name, name_size); + if (old_var) { + uv->used_storage -= variable_size(old_var); + del_variable(uv, old_var); + } + + new_var = add_variable(uv, guid, name, name_size, attributes); + new_var->data = g_malloc(data_size); + new_var->data_size = data_size; + memcpy(new_var->data, data, data_size); + uv->used_storage += variable_size(new_var); +} + +void uefi_vars_clear_volatile(uefi_vars_state *uv) +{ + uefi_variable *var, *n; + + QTAILQ_FOREACH_SAFE(var, &uv->variables, next, n) { + if (var->attributes & EFI_VARIABLE_NON_VOLATILE) { + continue; + } + uv->used_storage -= variable_size(var); + del_variable(uv, var); + } +} + +void uefi_vars_clear_all(uefi_vars_state *uv) +{ + uefi_variable *var, *n; + + QTAILQ_FOREACH_SAFE(var, &uv->variables, next, n) { + del_variable(uv, var); + } + uv->used_storage = 0; +} + +void uefi_vars_update_storage(uefi_vars_state *uv) +{ + uefi_variable *var; + + uv->used_storage = 0; + QTAILQ_FOREACH(var, &uv->variables, next) { + uv->used_storage += variable_size(var); + } +} + +static gboolean check_access(uefi_vars_state *uv, uefi_variable *var) +{ + if (!uv->exit_boot_service) { + if (!(var->attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)) { + return false; + } + } else { + if (!(var->attributes & EFI_VARIABLE_RUNTIME_ACCESS)) { + return false; + } + } + return true; +} + +static efi_status check_update(uefi_vars_state *uv, uefi_variable *old_var, + uefi_variable *new_var) +{ + efi_status status; + + if (old_var) { + if (!check_access(uv, old_var)) { + return EFI_ACCESS_DENIED; + } + } + + if (new_var) { + if (new_var->attributes & ~EFI_VARIABLE_ATTRIBUTE_SUPPORTED) { + return EFI_UNSUPPORTED; + } + if (!check_access(uv, new_var)) { + return EFI_ACCESS_DENIED; + } + } + + if (old_var && new_var) { + if (old_var->attributes != new_var->attributes) { + return EFI_INVALID_PARAMETER; + } + } + + if (new_var) { + /* create + update */ + status = uefi_vars_policy_check(uv, new_var, old_var == NULL); + } else { + /* delete */ + g_assert(old_var); + status = uefi_vars_policy_check(uv, old_var, false); + } + if (status != EFI_SUCCESS) { + return status; + } + + status = uefi_vars_check_secure_boot(uv, new_var ?: old_var); + if (status != EFI_SUCCESS) { + return status; + } + + return EFI_SUCCESS; +} + +static void append_write(uefi_variable *old_var, + uefi_variable *new_var) +{ + uefi_vars_siglist siglist; + uint64_t size; + void *data; + + uefi_vars_siglist_init(&siglist); + uefi_vars_siglist_parse(&siglist, old_var->data, old_var->data_size); + uefi_vars_siglist_parse(&siglist, new_var->data, new_var->data_size); + + size = uefi_vars_siglist_blob_size(&siglist); + data = g_malloc(size); + uefi_vars_siglist_blob_generate(&siglist, data, size); + + g_free(new_var->data); + new_var->data = data; + new_var->data_size = size; + + uefi_vars_siglist_free(&siglist); +} + +static size_t uefi_vars_mm_error(mm_header *mhdr, mm_variable *mvar, + uint64_t status) +{ + mvar->status = status; + return sizeof(*mvar); +} + +static size_t uefi_vars_mm_get_variable(uefi_vars_state *uv, mm_header *mhdr, + mm_variable *mvar, void *func) +{ + mm_variable_access *va = func; + uint16_t *name; + void *data; + uefi_variable *var; + uint64_t length; + + length = sizeof(*mvar) + sizeof(*va); + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + if (va->name_size > uv->max_storage || + va->data_size > uv->max_storage) { + return uefi_vars_mm_error(mhdr, mvar, EFI_OUT_OF_RESOURCES); + } + + name = func + sizeof(*va); + if (uadd64_overflow(length, va->name_size, &length)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + if (!uefi_str_is_valid(name, va->name_size, true)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_INVALID_PARAMETER); + } + + uefi_trace_variable(__func__, va->guid, name, va->name_size); + + var = uefi_vars_find_variable(uv, va->guid, name, va->name_size); + if (!var) { + return uefi_vars_mm_error(mhdr, mvar, EFI_NOT_FOUND); + } + + /* check permissions etc. */ + if (!check_access(uv, var)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_ACCESS_DENIED); + } + + data = func + sizeof(*va) + va->name_size; + if (uadd64_overflow(length, va->data_size, &length)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + if (uv->buf_size < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + va->attributes = var->attributes; + if (va->data_size < var->data_size) { + va->data_size = var->data_size; + length -= va->data_size; + mvar->status = EFI_BUFFER_TOO_SMALL; + } else { + va->data_size = var->data_size; + memcpy(data, var->data, var->data_size); + mvar->status = EFI_SUCCESS; + } + return length; +} + +static size_t +uefi_vars_mm_get_next_variable(uefi_vars_state *uv, mm_header *mhdr, + mm_variable *mvar, void *func) +{ + mm_next_variable *nv = func; + uefi_variable *var; + uint16_t *name; + uint64_t length; + + length = sizeof(*mvar) + sizeof(*nv); + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + if (nv->name_size > uv->max_storage) { + return uefi_vars_mm_error(mhdr, mvar, EFI_OUT_OF_RESOURCES); + } + + name = func + sizeof(*nv); + if (uadd64_overflow(length, nv->name_size, &length)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + if (!uefi_str_is_valid(name, nv->name_size, true)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_INVALID_PARAMETER); + } + + if (uefi_strlen(name, nv->name_size) == 0) { + /* empty string -> first */ + var = QTAILQ_FIRST(&uv->variables); + if (!var) { + return uefi_vars_mm_error(mhdr, mvar, EFI_NOT_FOUND); + } + } else { + var = uefi_vars_find_variable(uv, nv->guid, name, nv->name_size); + if (!var) { + return uefi_vars_mm_error(mhdr, mvar, EFI_INVALID_PARAMETER); + } + do { + var = QTAILQ_NEXT(var, next); + } while (var && !check_access(uv, var)); + if (!var) { + return uefi_vars_mm_error(mhdr, mvar, EFI_NOT_FOUND); + } + } + + length = sizeof(*mvar) + sizeof(*nv) + var->name_size; + if (uv->buf_size < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + nv->guid = var->guid; + nv->name_size = var->name_size; + memcpy(name, var->name, var->name_size); + mvar->status = EFI_SUCCESS; + return length; +} + +static bool uefi_vars_mm_digest_compare(uefi_variable *old_var, + uefi_variable *new_var) +{ + if (!old_var->digest || + !new_var->digest || + !old_var->digest_size || + !new_var->digest_size) { + /* should not happen */ + trace_uefi_vars_security_violation("inconsistent authvar digest state"); + return false; + } + if (old_var->digest_size != new_var->digest_size) { + trace_uefi_vars_security_violation("authvar digest size mismatch"); + return false; + } + if (memcmp(old_var->digest, new_var->digest, + old_var->digest_size) != 0) { + trace_uefi_vars_security_violation("authvar digest data mismatch"); + return false; + } + return true; +} + +static size_t uefi_vars_mm_set_variable(uefi_vars_state *uv, mm_header *mhdr, + mm_variable *mvar, void *func) +{ + mm_variable_access *va = func; + uint32_t attributes = 0; + uint16_t *name; + void *data; + uefi_variable *old_var, *new_var; + uint64_t length; + size_t new_storage; + efi_status status; + + length = sizeof(*mvar) + sizeof(*va); + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + if (va->name_size > uv->max_storage || + va->data_size > uv->max_storage) { + return uefi_vars_mm_error(mhdr, mvar, EFI_OUT_OF_RESOURCES); + } + + name = func + sizeof(*va); + if (uadd64_overflow(length, va->name_size, &length)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + data = func + sizeof(*va) + va->name_size; + if (uadd64_overflow(length, va->data_size, &length)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + g_assert(va->name_size < G_MAXUINT32); + g_assert(va->data_size < G_MAXUINT32); + + if (!uefi_str_is_valid(name, va->name_size, true)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_INVALID_PARAMETER); + } + + uefi_trace_variable(__func__, va->guid, name, va->name_size); + + old_var = uefi_vars_find_variable(uv, va->guid, name, va->name_size); + if (va->data_size) { + new_var = add_variable(uv, va->guid, name, va->name_size, + va->attributes); + if (va->attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) { + /* not implemented (deprecated in uefi spec) */ + warn_report("%s: AUTHENTICATED_WRITE_ACCESS", __func__); + mvar->status = EFI_UNSUPPORTED; + goto rollback; + } else if (va->attributes & + EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) { + status = uefi_vars_check_auth_2(uv, new_var, va, data); + if (status != EFI_SUCCESS) { + mvar->status = status; + goto rollback; + } + if (old_var && new_var) { + if (uefi_time_compare(&old_var->time, &new_var->time) > 0) { + trace_uefi_vars_security_violation("time check failed"); + mvar->status = EFI_SECURITY_VIOLATION; + goto rollback; + } + if (old_var->digest_size || new_var->digest_size) { + if (!uefi_vars_mm_digest_compare(old_var, new_var)) { + mvar->status = EFI_SECURITY_VIOLATION; + goto rollback; + } + } + } + } else { + new_var->data = g_malloc(va->data_size); + memcpy(new_var->data, data, va->data_size); + new_var->data_size = va->data_size; + } + if (!new_var->data) { + /* we land here when deleting authenticated variables */ + del_variable(uv, new_var); + new_var = NULL; + } + } else { + new_var = NULL; + } + + if (!old_var && !new_var) { + /* delete non-existing variable -> nothing to do */ + mvar->status = EFI_SUCCESS; + return sizeof(*mvar); + } + + /* check permissions etc. */ + status = check_update(uv, old_var, new_var); + if (status != EFI_SUCCESS) { + mvar->status = status; + goto rollback; + } + + if (va->attributes & EFI_VARIABLE_APPEND_WRITE && old_var && new_var) { + /* merge signature databases */ + if (!uefi_vars_is_sb_any(new_var)) { + mvar->status = EFI_UNSUPPORTED; + goto rollback; + } + append_write(old_var, new_var); + } + + /* check storage space */ + new_storage = uv->used_storage; + if (old_var) { + new_storage -= variable_size(old_var); + } + if (new_var) { + new_storage += variable_size(new_var); + } + if (new_storage > uv->max_storage) { + mvar->status = EFI_OUT_OF_RESOURCES; + goto rollback; + } + + attributes = new_var + ? new_var->attributes + : old_var->attributes; + + /* all good, commit */ + del_variable(uv, old_var); + uv->used_storage = new_storage; + + if (attributes & EFI_VARIABLE_NON_VOLATILE) { + uefi_vars_json_save(uv); + } + + if (new_var && uefi_vars_is_sb_pk(new_var)) { + uefi_vars_auth_init(uv); + } + + mvar->status = EFI_SUCCESS; + return sizeof(*mvar); + +rollback: + del_variable(uv, new_var); + return sizeof(*mvar); +} + +static size_t uefi_vars_mm_variable_info(uefi_vars_state *uv, mm_header *mhdr, + mm_variable *mvar, void *func) +{ + mm_variable_info *vi = func; + uint64_t length; + + length = sizeof(*mvar) + sizeof(*vi); + if (uv->buf_size < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + vi->max_storage_size = uv->max_storage; + vi->free_storage_size = uv->max_storage - uv->used_storage; + vi->max_variable_size = uv->max_storage >> 2; + vi->attributes = 0; + + mvar->status = EFI_SUCCESS; + return length; +} + +static size_t +uefi_vars_mm_get_payload_size(uefi_vars_state *uv, mm_header *mhdr, + mm_variable *mvar, void *func) +{ + mm_get_payload_size *ps = func; + uint64_t length; + + length = sizeof(*mvar) + sizeof(*ps); + if (uv->buf_size < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + ps->payload_size = uv->buf_size; + mvar->status = EFI_SUCCESS; + return length; +} + +static size_t +uefi_vars_mm_lock_variable(uefi_vars_state *uv, mm_header *mhdr, + mm_variable *mvar, void *func) +{ + mm_lock_variable *lv = func; + variable_policy_entry *pe; + uint16_t *name, *dest; + uint64_t length; + + length = sizeof(*mvar) + sizeof(*lv); + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + name = func + sizeof(*lv); + if (uadd64_overflow(length, lv->name_size, &length)) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + if (mhdr->length < length) { + return uefi_vars_mm_error(mhdr, mvar, EFI_BAD_BUFFER_SIZE); + } + + uefi_trace_variable(__func__, lv->guid, name, lv->name_size); + + pe = g_malloc0(sizeof(*pe) + lv->name_size); + pe->version = VARIABLE_POLICY_ENTRY_REVISION; + pe->size = sizeof(*pe) + lv->name_size; + pe->offset_to_name = sizeof(*pe); + pe->namespace = lv->guid; + pe->min_size = 0; + pe->max_size = UINT32_MAX; + pe->attributes_must_have = 0; + pe->attributes_cant_have = 0; + pe->lock_policy_type = VARIABLE_POLICY_TYPE_LOCK_NOW; + + dest = (void *)pe + pe->offset_to_name; + memcpy(dest, name, lv->name_size); + + uefi_vars_add_policy(uv, pe); + g_free(pe); + + mvar->status = EFI_SUCCESS; + return length; +} + +uint32_t uefi_vars_mm_vars_proto(uefi_vars_state *uv) +{ + static const char *fnames[] = { + "zero", + "get-variable", + "get-next-variable-name", + "set-variable", + "query-variable-info", + "ready-to-boot", + "exit-boot-service", + "get-statistics", + "lock-variable", + "var-check-prop-set", + "var-check-prop-get", + "get-payload-size", + "init-runtime-cache-contect", + "sync-runtime-cache", + "get-runtime-cache-info", + }; + const char *fname; + uint64_t length; + + mm_header *mhdr = (mm_header *) uv->buffer; + mm_variable *mvar = (mm_variable *) (uv->buffer + sizeof(*mhdr)); + void *func = (uv->buffer + sizeof(*mhdr) + sizeof(*mvar)); + + if (mhdr->length < sizeof(*mvar)) { + return UEFI_VARS_STS_ERR_BAD_BUFFER_SIZE; + } + + fname = mvar->function < ARRAY_SIZE(fnames) + ? fnames[mvar->function] + : "unknown"; + trace_uefi_vars_proto_cmd(fname); + + switch (mvar->function) { + case SMM_VARIABLE_FUNCTION_GET_VARIABLE: + length = uefi_vars_mm_get_variable(uv, mhdr, mvar, func); + break; + + case SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME: + length = uefi_vars_mm_get_next_variable(uv, mhdr, mvar, func); + break; + + case SMM_VARIABLE_FUNCTION_SET_VARIABLE: + length = uefi_vars_mm_set_variable(uv, mhdr, mvar, func); + break; + + case SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO: + length = uefi_vars_mm_variable_info(uv, mhdr, mvar, func); + break; + + case SMM_VARIABLE_FUNCTION_LOCK_VARIABLE: + length = uefi_vars_mm_lock_variable(uv, mhdr, mvar, func); + break; + + case SMM_VARIABLE_FUNCTION_GET_PAYLOAD_SIZE: + length = uefi_vars_mm_get_payload_size(uv, mhdr, mvar, func); + break; + + case SMM_VARIABLE_FUNCTION_READY_TO_BOOT: + trace_uefi_event("ready-to-boot"); + uv->ready_to_boot = true; + length = 0; + break; + + case SMM_VARIABLE_FUNCTION_EXIT_BOOT_SERVICE: + trace_uefi_event("exit-boot-service"); + uv->exit_boot_service = true; + length = 0; + break; + + default: + length = uefi_vars_mm_error(mhdr, mvar, EFI_UNSUPPORTED); + break; + } + + if (mhdr->length < length) { + mvar->status = EFI_BUFFER_TOO_SMALL; + } + + uefi_trace_status(__func__, mvar->status); + return UEFI_VARS_STS_SUCCESS; +} From f1488fac0584cc095865e4d4d987f01f4e97fbe5 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:12 +0100 Subject: [PATCH 08/24] hw/uefi: add var-service-auth.c This implements authenticated variable handling (see AuthVariableLib in edk2). The by far most common use case for auth variables is secure boot. The secure boot certificate databases ('PK', 'KEK', 'db' and 'dbx') are authenticated variables, with update rules being specified in the UEFI specification. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-9-kraxel@redhat.com> --- hw/uefi/var-service-auth.c | 361 +++++++++++++++++++++++++++++++++++++ 1 file changed, 361 insertions(+) create mode 100644 hw/uefi/var-service-auth.c diff --git a/hw/uefi/var-service-auth.c b/hw/uefi/var-service-auth.c new file mode 100644 index 0000000000..fba5a0956a --- /dev/null +++ b/hw/uefi/var-service-auth.c @@ -0,0 +1,361 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - AuthVariableLib + */ + +#include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "system/dma.h" + +#include "hw/uefi/var-service.h" + +static const uint16_t name_pk[] = u"PK"; +static const uint16_t name_kek[] = u"KEK"; +static const uint16_t name_db[] = u"db"; +static const uint16_t name_dbx[] = u"dbx"; +static const uint16_t name_setup_mode[] = u"SetupMode"; +static const uint16_t name_sigs_support[] = u"SignatureSupport"; +static const uint16_t name_sb[] = u"SecureBoot"; +static const uint16_t name_sb_enable[] = u"SecureBootEnable"; +static const uint16_t name_custom_mode[] = u"CustomMode"; +static const uint16_t name_vk[] = u"VendorKeys"; +static const uint16_t name_vk_nv[] = u"VendorKeysNv"; + +static const uint32_t sigdb_attrs = + EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS | + EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS; + +static void set_secure_boot(uefi_vars_state *uv, uint8_t sb) +{ + uefi_vars_set_variable(uv, EfiGlobalVariable, + name_sb, sizeof(name_sb), + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS, + &sb, sizeof(sb)); +} + +static void set_secure_boot_enable(uefi_vars_state *uv, uint8_t sbe) +{ + uefi_vars_set_variable(uv, EfiSecureBootEnableDisable, + name_sb_enable, sizeof(name_sb_enable), + EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS, + &sbe, sizeof(sbe)); +} + +static void set_setup_mode(uefi_vars_state *uv, uint8_t sm) +{ + uefi_vars_set_variable(uv, EfiGlobalVariable, + name_setup_mode, sizeof(name_setup_mode), + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS, + &sm, sizeof(sm)); +} + +static void set_custom_mode(uefi_vars_state *uv, uint8_t cm) +{ + uefi_vars_set_variable(uv, EfiCustomModeEnable, + name_custom_mode, sizeof(name_custom_mode), + EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS, + &cm, sizeof(cm)); +} + +static void set_signature_support(uefi_vars_state *uv) +{ + QemuUUID sigs_support[5]; + + sigs_support[0] = EfiCertSha256Guid; + sigs_support[1] = EfiCertSha384Guid; + sigs_support[2] = EfiCertSha512Guid; + sigs_support[3] = EfiCertRsa2048Guid; + sigs_support[4] = EfiCertX509Guid; + + uefi_vars_set_variable(uv, EfiGlobalVariable, + name_sigs_support, sizeof(name_sigs_support), + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS, + sigs_support, sizeof(sigs_support)); +} + +static bool setup_mode_is_active(uefi_vars_state *uv) +{ + uefi_variable *var; + uint8_t *value; + + var = uefi_vars_find_variable(uv, EfiGlobalVariable, + name_setup_mode, sizeof(name_setup_mode)); + if (var) { + value = var->data; + if (value[0] == SETUP_MODE) { + return true; + } + } + return false; +} + +static bool custom_mode_is_active(uefi_vars_state *uv) +{ + uefi_variable *var; + uint8_t *value; + + var = uefi_vars_find_variable(uv, EfiCustomModeEnable, + name_custom_mode, sizeof(name_custom_mode)); + if (var) { + value = var->data; + if (value[0] == CUSTOM_SECURE_BOOT_MODE) { + return true; + } + } + return false; +} + +bool uefi_vars_is_sb_pk(uefi_variable *var) +{ + if (qemu_uuid_is_equal(&var->guid, &EfiGlobalVariable) && + uefi_str_equal(var->name, var->name_size, name_pk, sizeof(name_pk))) { + return true; + } + return false; +} + +static bool uefi_vars_is_sb_kek(uefi_variable *var) +{ + if (qemu_uuid_is_equal(&var->guid, &EfiGlobalVariable) && + uefi_str_equal(var->name, var->name_size, name_kek, sizeof(name_kek))) { + return true; + } + return false; +} + +static bool uefi_vars_is_sb_db(uefi_variable *var) +{ + if (!qemu_uuid_is_equal(&var->guid, &EfiImageSecurityDatabase)) { + return false; + } + if (uefi_str_equal(var->name, var->name_size, name_db, sizeof(name_db))) { + return true; + } + if (uefi_str_equal(var->name, var->name_size, name_dbx, sizeof(name_dbx))) { + return true; + } + return false; +} + +bool uefi_vars_is_sb_any(uefi_variable *var) +{ + if (uefi_vars_is_sb_pk(var) || + uefi_vars_is_sb_kek(var) || + uefi_vars_is_sb_db(var)) { + return true; + } + return false; +} + +static uefi_variable *uefi_vars_find_siglist(uefi_vars_state *uv, + uefi_variable *var) +{ + if (uefi_vars_is_sb_pk(var)) { + return uefi_vars_find_variable(uv, EfiGlobalVariable, + name_pk, sizeof(name_pk)); + } + if (uefi_vars_is_sb_kek(var)) { + return uefi_vars_find_variable(uv, EfiGlobalVariable, + name_pk, sizeof(name_pk)); + } + if (uefi_vars_is_sb_db(var)) { + return uefi_vars_find_variable(uv, EfiGlobalVariable, + name_kek, sizeof(name_kek)); + } + + return NULL; +} + +static efi_status uefi_vars_check_auth_2_sb(uefi_vars_state *uv, + uefi_variable *var, + mm_variable_access *va, + void *data, + uint64_t data_offset) +{ + variable_auth_2 *auth = data; + uefi_variable *siglist; + + if (custom_mode_is_active(uv)) { + /* no authentication in custom mode */ + return EFI_SUCCESS; + } + + if (setup_mode_is_active(uv) && !uefi_vars_is_sb_pk(var)) { + /* no authentication in setup mode (except PK) */ + return EFI_SUCCESS; + } + + if (auth->hdr_length == 24) { + /* no signature (auth->cert_data is empty) */ + return EFI_SECURITY_VIOLATION; + } + + siglist = uefi_vars_find_siglist(uv, var); + if (!siglist && setup_mode_is_active(uv) && uefi_vars_is_sb_pk(var)) { + /* check PK is self-signed */ + uefi_variable tmp = { + .guid = EfiGlobalVariable, + .name = (uint16_t *)name_pk, + .name_size = sizeof(name_pk), + .attributes = sigdb_attrs, + .data = data + data_offset, + .data_size = va->data_size - data_offset, + }; + return uefi_vars_check_pkcs7_2(&tmp, NULL, NULL, va, data); + } + + return uefi_vars_check_pkcs7_2(siglist, NULL, NULL, va, data); +} + +efi_status uefi_vars_check_auth_2(uefi_vars_state *uv, uefi_variable *var, + mm_variable_access *va, void *data) +{ + variable_auth_2 *auth = data; + uint64_t data_offset; + efi_status status; + + if (va->data_size < sizeof(*auth)) { + return EFI_SECURITY_VIOLATION; + } + if (uadd64_overflow(sizeof(efi_time), auth->hdr_length, &data_offset)) { + return EFI_SECURITY_VIOLATION; + } + if (va->data_size < data_offset) { + return EFI_SECURITY_VIOLATION; + } + + if (auth->hdr_revision != 0x0200 || + auth->hdr_cert_type != WIN_CERT_TYPE_EFI_GUID || + !qemu_uuid_is_equal(&auth->guid_cert_type, &EfiCertTypePkcs7Guid)) { + return EFI_UNSUPPORTED; + } + + if (uefi_vars_is_sb_any(var)) { + /* secure boot variables */ + status = uefi_vars_check_auth_2_sb(uv, var, va, data, data_offset); + if (status != EFI_SUCCESS) { + return status; + } + } else { + /* other authenticated variables */ + status = uefi_vars_check_pkcs7_2(NULL, + &var->digest, &var->digest_size, + va, data); + if (status != EFI_SUCCESS) { + return status; + } + } + + /* checks passed, set variable data */ + var->time = auth->timestamp; + if (va->data_size - data_offset > 0) { + var->data = g_malloc(va->data_size - data_offset); + memcpy(var->data, data + data_offset, va->data_size - data_offset); + var->data_size = va->data_size - data_offset; + } + + return EFI_SUCCESS; +} + +efi_status uefi_vars_check_secure_boot(uefi_vars_state *uv, uefi_variable *var) +{ + uint8_t *value = var->data; + + if (uefi_vars_is_sb_any(var)) { + if (var->attributes != sigdb_attrs) { + return EFI_INVALID_PARAMETER; + } + } + + /* reject SecureBootEnable updates if force_secure_boot is set */ + if (qemu_uuid_is_equal(&var->guid, &EfiSecureBootEnableDisable) && + uefi_str_equal(var->name, var->name_size, + name_sb_enable, sizeof(name_sb_enable)) && + uv->force_secure_boot && + value[0] != SECURE_BOOT_ENABLE) { + return EFI_WRITE_PROTECTED; + } + + /* reject CustomMode updates if disable_custom_mode is set */ + if (qemu_uuid_is_equal(&var->guid, &EfiCustomModeEnable) && + uefi_str_equal(var->name, var->name_size, + name_custom_mode, sizeof(name_custom_mode)) && + uv->disable_custom_mode) { + return EFI_WRITE_PROTECTED; + } + + return EFI_SUCCESS; +} + +/* AuthVariableLibInitialize */ +void uefi_vars_auth_init(uefi_vars_state *uv) +{ + uefi_variable *pk_var, *sbe_var; + uint8_t platform_mode, sb, sbe, vk; + + /* SetupMode */ + pk_var = uefi_vars_find_variable(uv, EfiGlobalVariable, + name_pk, sizeof(name_pk)); + if (!pk_var) { + platform_mode = SETUP_MODE; + } else { + platform_mode = USER_MODE; + } + set_setup_mode(uv, platform_mode); + + /* SignatureSupport */ + set_signature_support(uv); + + /* SecureBootEnable */ + sbe = SECURE_BOOT_DISABLE; + sbe_var = uefi_vars_find_variable(uv, EfiSecureBootEnableDisable, + name_sb_enable, sizeof(name_sb_enable)); + if (sbe_var) { + if (platform_mode == USER_MODE) { + sbe = ((uint8_t *)sbe_var->data)[0]; + } + } else if (platform_mode == USER_MODE) { + sbe = SECURE_BOOT_ENABLE; + set_secure_boot_enable(uv, sbe); + } + + if (uv->force_secure_boot && sbe != SECURE_BOOT_ENABLE) { + sbe = SECURE_BOOT_ENABLE; + set_secure_boot_enable(uv, sbe); + } + + /* SecureBoot */ + if ((sbe == SECURE_BOOT_ENABLE) && (platform_mode == USER_MODE)) { + sb = SECURE_BOOT_MODE_ENABLE; + } else { + sb = SECURE_BOOT_MODE_DISABLE; + } + set_secure_boot(uv, sb); + + /* CustomMode */ + set_custom_mode(uv, STANDARD_SECURE_BOOT_MODE); + + vk = 0; + uefi_vars_set_variable(uv, EfiGlobalVariable, + name_vk_nv, sizeof(name_vk_nv), + EFI_VARIABLE_NON_VOLATILE | + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, + &vk, sizeof(vk)); + uefi_vars_set_variable(uv, EfiGlobalVariable, + name_vk, sizeof(name_vk), + EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS, + &vk, sizeof(vk)); + + /* flush to disk */ + uefi_vars_json_save(uv); +} From 034cb968ca8fc562ea11de516828228eeb146944 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:13 +0100 Subject: [PATCH 09/24] hw/uefi: add var-service-policy.c Implement variable policies (Edk2VariablePolicyProtocol). This EFI protocol allows to define restrictions for variables. It also allows to lock down variables (disallow write access). Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-10-kraxel@redhat.com> --- hw/uefi/var-service-policy.c | 370 +++++++++++++++++++++++++++++++++++ 1 file changed, 370 insertions(+) create mode 100644 hw/uefi/var-service-policy.c diff --git a/hw/uefi/var-service-policy.c b/hw/uefi/var-service-policy.c new file mode 100644 index 0000000000..3b1155fe4e --- /dev/null +++ b/hw/uefi/var-service-policy.c @@ -0,0 +1,370 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - VarCheckPolicyLibMmiHandler implementation + * + * variable policy specs: + * https://github.com/tianocore/edk2/blob/master/MdeModulePkg/Library/VariablePolicyLib/ReadMe.md + */ +#include "qemu/osdep.h" +#include "system/dma.h" +#include "migration/vmstate.h" + +#include "hw/uefi/var-service.h" +#include "hw/uefi/var-service-api.h" +#include "hw/uefi/var-service-edk2.h" + +#include "trace/trace-hw_uefi.h" + +static void calc_policy(uefi_var_policy *pol); + +static int uefi_var_policy_post_load(void *opaque, int version_id) +{ + uefi_var_policy *pol = opaque; + + calc_policy(pol); + return 0; +} + +const VMStateDescription vmstate_uefi_var_policy = { + .name = "uefi-var-policy", + .post_load = uefi_var_policy_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT32(entry_size, uefi_var_policy), + VMSTATE_VBUFFER_ALLOC_UINT32(entry, uefi_var_policy, + 0, NULL, entry_size), + VMSTATE_END_OF_LIST() + }, +}; + +static void print_policy_entry(variable_policy_entry *pe) +{ + uint16_t *name = (void *)pe + pe->offset_to_name; + + fprintf(stderr, "%s:\n", __func__); + + fprintf(stderr, " name ´"); + while (*name) { + fprintf(stderr, "%c", *name); + name++; + } + fprintf(stderr, "', version=%d.%d, size=%d\n", + pe->version >> 16, pe->version & 0xffff, pe->size); + + if (pe->min_size) { + fprintf(stderr, " size min=%d\n", pe->min_size); + } + if (pe->max_size != UINT32_MAX) { + fprintf(stderr, " size max=%u\n", pe->max_size); + } + if (pe->attributes_must_have) { + fprintf(stderr, " attr must=0x%x\n", pe->attributes_must_have); + } + if (pe->attributes_cant_have) { + fprintf(stderr, " attr cant=0x%x\n", pe->attributes_cant_have); + } + if (pe->lock_policy_type) { + fprintf(stderr, " lock policy type %d\n", pe->lock_policy_type); + } +} + +static gboolean wildcard_str_equal(uefi_var_policy *pol, + uefi_variable *var) +{ + return uefi_str_equal_ex(pol->name, pol->name_size, + var->name, var->name_size, + true); +} + +static uefi_var_policy *find_policy(uefi_vars_state *uv, QemuUUID guid, + uint16_t *name, uint64_t name_size) +{ + uefi_var_policy *pol; + + QTAILQ_FOREACH(pol, &uv->var_policies, next) { + if (!qemu_uuid_is_equal(&pol->entry->namespace, &guid)) { + continue; + } + if (!uefi_str_equal(pol->name, pol->name_size, + name, name_size)) { + continue; + } + return pol; + } + return NULL; +} + +static uefi_var_policy *wildcard_find_policy(uefi_vars_state *uv, + uefi_variable *var) +{ + uefi_var_policy *pol; + + QTAILQ_FOREACH(pol, &uv->var_policies, next) { + if (!qemu_uuid_is_equal(&pol->entry->namespace, &var->guid)) { + continue; + } + if (!wildcard_str_equal(pol, var)) { + continue; + } + return pol; + } + return NULL; +} + +static void calc_policy(uefi_var_policy *pol) +{ + variable_policy_entry *pe = pol->entry; + unsigned int i; + + pol->name = (void *)pol->entry + pe->offset_to_name; + pol->name_size = pe->size - pe->offset_to_name; + + for (i = 0; i < pol->name_size / 2; i++) { + if (pol->name[i] == '#') { + pol->hashmarks++; + } + } +} + +uefi_var_policy *uefi_vars_add_policy(uefi_vars_state *uv, + variable_policy_entry *pe) +{ + uefi_var_policy *pol, *p; + + pol = g_new0(uefi_var_policy, 1); + pol->entry = g_malloc(pe->size); + memcpy(pol->entry, pe, pe->size); + pol->entry_size = pe->size; + + calc_policy(pol); + + /* keep list sorted by priority, add to tail of priority group */ + QTAILQ_FOREACH(p, &uv->var_policies, next) { + if ((p->hashmarks > pol->hashmarks) || + (!p->name_size && pol->name_size)) { + QTAILQ_INSERT_BEFORE(p, pol, next); + return pol; + } + } + + QTAILQ_INSERT_TAIL(&uv->var_policies, pol, next); + return pol; +} + +efi_status uefi_vars_policy_check(uefi_vars_state *uv, + uefi_variable *var, + gboolean is_newvar) +{ + uefi_var_policy *pol; + variable_policy_entry *pe; + variable_lock_on_var_state *lvarstate; + uint16_t *lvarname; + size_t lvarnamesize; + uefi_variable *lvar; + + if (!uv->end_of_dxe) { + return EFI_SUCCESS; + } + + pol = wildcard_find_policy(uv, var); + if (!pol) { + return EFI_SUCCESS; + } + pe = pol->entry; + + uefi_trace_variable(__func__, var->guid, var->name, var->name_size); + print_policy_entry(pe); + + if ((var->attributes & pe->attributes_must_have) != pe->attributes_must_have) { + trace_uefi_vars_policy_deny("must-have-attr"); + return EFI_INVALID_PARAMETER; + } + if ((var->attributes & pe->attributes_cant_have) != 0) { + trace_uefi_vars_policy_deny("cant-have-attr"); + return EFI_INVALID_PARAMETER; + } + + if (var->data_size < pe->min_size) { + trace_uefi_vars_policy_deny("min-size"); + return EFI_INVALID_PARAMETER; + } + if (var->data_size > pe->max_size) { + trace_uefi_vars_policy_deny("max-size"); + return EFI_INVALID_PARAMETER; + } + + switch (pe->lock_policy_type) { + case VARIABLE_POLICY_TYPE_NO_LOCK: + break; + + case VARIABLE_POLICY_TYPE_LOCK_NOW: + trace_uefi_vars_policy_deny("lock-now"); + return EFI_WRITE_PROTECTED; + + case VARIABLE_POLICY_TYPE_LOCK_ON_CREATE: + if (!is_newvar) { + trace_uefi_vars_policy_deny("lock-on-create"); + return EFI_WRITE_PROTECTED; + } + break; + + case VARIABLE_POLICY_TYPE_LOCK_ON_VAR_STATE: + lvarstate = (void *)pol->entry + sizeof(*pe); + lvarname = (void *)pol->entry + sizeof(*pe) + sizeof(*lvarstate); + lvarnamesize = pe->offset_to_name - sizeof(*pe) - sizeof(*lvarstate); + + uefi_trace_variable(__func__, lvarstate->namespace, + lvarname, lvarnamesize); + lvar = uefi_vars_find_variable(uv, lvarstate->namespace, + lvarname, lvarnamesize); + if (lvar && lvar->data_size == 1) { + uint8_t *value = lvar->data; + if (lvarstate->value == *value) { + return EFI_WRITE_PROTECTED; + } + } + break; + } + + return EFI_SUCCESS; +} + +void uefi_vars_policies_clear(uefi_vars_state *uv) +{ + uefi_var_policy *pol; + + while (!QTAILQ_EMPTY(&uv->var_policies)) { + pol = QTAILQ_FIRST(&uv->var_policies); + QTAILQ_REMOVE(&uv->var_policies, pol, next); + g_free(pol->entry); + g_free(pol); + } +} + +static size_t uefi_vars_mm_policy_error(mm_header *mhdr, + mm_check_policy *mchk, + uint64_t status) +{ + mchk->result = status; + return sizeof(*mchk); +} + +static uint32_t uefi_vars_mm_check_policy_is_enabled(uefi_vars_state *uv, + mm_header *mhdr, + mm_check_policy *mchk, + void *func) +{ + mm_check_policy_is_enabled *mpar = func; + size_t length; + + length = sizeof(*mchk) + sizeof(*mpar); + if (mhdr->length < length) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_BAD_BUFFER_SIZE); + } + + mpar->state = TRUE; + mchk->result = EFI_SUCCESS; + return sizeof(*mchk); +} + +static uint32_t uefi_vars_mm_check_policy_register(uefi_vars_state *uv, + mm_header *mhdr, + mm_check_policy *mchk, + void *func) +{ + variable_policy_entry *pe = func; + uefi_var_policy *pol; + uint64_t length; + + if (uadd64_overflow(sizeof(*mchk), pe->size, &length)) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_BAD_BUFFER_SIZE); + } + if (mhdr->length < length) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_BAD_BUFFER_SIZE); + } + if (pe->size < sizeof(*pe)) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_BAD_BUFFER_SIZE); + } + if (pe->offset_to_name < sizeof(*pe)) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_BAD_BUFFER_SIZE); + } + + if (pe->lock_policy_type == VARIABLE_POLICY_TYPE_LOCK_ON_VAR_STATE && + pe->offset_to_name < sizeof(*pe) + sizeof(variable_lock_on_var_state)) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_BAD_BUFFER_SIZE); + } + + /* check space for minimum string length */ + if (pe->size < (size_t)pe->offset_to_name) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_BAD_BUFFER_SIZE); + } + + if (!uefi_str_is_valid((void *)pe + pe->offset_to_name, + pe->size - pe->offset_to_name, + false)) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_INVALID_PARAMETER); + } + + pol = find_policy(uv, pe->namespace, + (void *)pe + pe->offset_to_name, + pe->size - pe->offset_to_name); + if (pol) { + return uefi_vars_mm_policy_error(mhdr, mchk, EFI_ALREADY_STARTED); + } + + uefi_vars_add_policy(uv, pe); + + mchk->result = EFI_SUCCESS; + return sizeof(*mchk); +} + +uint32_t uefi_vars_mm_check_policy_proto(uefi_vars_state *uv) +{ + static const char *fnames[] = { + "zero", + "disable", + "is-enabled", + "register", + "dump", + "lock", + }; + const char *fname; + mm_header *mhdr = (mm_header *) uv->buffer; + mm_check_policy *mchk = (mm_check_policy *) (uv->buffer + sizeof(*mhdr)); + void *func = (uv->buffer + sizeof(*mhdr) + sizeof(*mchk)); + + if (mhdr->length < sizeof(*mchk)) { + return UEFI_VARS_STS_ERR_BAD_BUFFER_SIZE; + } + + fname = mchk->command < ARRAY_SIZE(fnames) + ? fnames[mchk->command] + : "unknown"; + trace_uefi_vars_policy_cmd(fname); + + switch (mchk->command) { + case VAR_CHECK_POLICY_COMMAND_DISABLE: + mchk->result = EFI_UNSUPPORTED; + break; + case VAR_CHECK_POLICY_COMMAND_IS_ENABLED: + uefi_vars_mm_check_policy_is_enabled(uv, mhdr, mchk, func); + break; + case VAR_CHECK_POLICY_COMMAND_REGISTER: + if (uv->policy_locked) { + mchk->result = EFI_WRITE_PROTECTED; + } else { + uefi_vars_mm_check_policy_register(uv, mhdr, mchk, func); + } + break; + case VAR_CHECK_POLICY_COMMAND_LOCK: + uv->policy_locked = true; + mchk->result = EFI_SUCCESS; + break; + default: + mchk->result = EFI_UNSUPPORTED; + break; + } + + uefi_trace_status(__func__, mchk->result); + return UEFI_VARS_STS_SUCCESS; +} From 90ca4e03c27dc8ac821a2e1686e705ae9a93d301 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:14 +0100 Subject: [PATCH 10/24] hw/uefi: add var-service-core.c This is the core code for guest <-> host communication. This accepts request messages from the guest, dispatches them to the service called, and sends back the response message. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-11-kraxel@redhat.com> --- hw/uefi/var-service-core.c | 321 +++++++++++++++++++++++++++++++++++++ 1 file changed, 321 insertions(+) create mode 100644 hw/uefi/var-service-core.c diff --git a/hw/uefi/var-service-core.c b/hw/uefi/var-service-core.c new file mode 100644 index 0000000000..8ed8378ab9 --- /dev/null +++ b/hw/uefi/var-service-core.c @@ -0,0 +1,321 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device + */ +#include "qemu/osdep.h" +#include "qemu/crc32c.h" +#include "system/dma.h" +#include "migration/vmstate.h" + +#include "hw/uefi/var-service.h" +#include "hw/uefi/var-service-api.h" +#include "hw/uefi/var-service-edk2.h" + +#include "trace/trace-hw_uefi.h" + +static int uefi_vars_pre_load(void *opaque) +{ + uefi_vars_state *uv = opaque; + + uefi_vars_clear_all(uv); + uefi_vars_policies_clear(uv); + g_free(uv->buffer); + return 0; +} + +static int uefi_vars_post_load(void *opaque, int version_id) +{ + uefi_vars_state *uv = opaque; + + uefi_vars_update_storage(uv); + uv->buffer = g_malloc(uv->buf_size); + return 0; +} + +const VMStateDescription vmstate_uefi_vars = { + .name = "uefi-vars", + .pre_load = uefi_vars_pre_load, + .post_load = uefi_vars_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT16(sts, uefi_vars_state), + VMSTATE_UINT32(buf_size, uefi_vars_state), + VMSTATE_UINT32(buf_addr_lo, uefi_vars_state), + VMSTATE_UINT32(buf_addr_hi, uefi_vars_state), + VMSTATE_UINT32(pio_xfer_offset, uefi_vars_state), + VMSTATE_VBUFFER_ALLOC_UINT32(pio_xfer_buffer, uefi_vars_state, + 0, NULL, buf_size), + VMSTATE_BOOL(end_of_dxe, uefi_vars_state), + VMSTATE_BOOL(ready_to_boot, uefi_vars_state), + VMSTATE_BOOL(exit_boot_service, uefi_vars_state), + VMSTATE_BOOL(policy_locked, uefi_vars_state), + VMSTATE_UINT64(used_storage, uefi_vars_state), + VMSTATE_QTAILQ_V(variables, uefi_vars_state, 0, + vmstate_uefi_variable, uefi_variable, next), + VMSTATE_QTAILQ_V(var_policies, uefi_vars_state, 0, + vmstate_uefi_var_policy, uefi_var_policy, next), + VMSTATE_END_OF_LIST() + }, +}; + +static uint32_t uefi_vars_cmd_mm(uefi_vars_state *uv, bool dma_mode) +{ + hwaddr dma; + mm_header *mhdr; + uint64_t size; + uint32_t retval; + + dma = uv->buf_addr_lo | ((hwaddr)uv->buf_addr_hi << 32); + mhdr = (mm_header *) uv->buffer; + + if (!uv->buffer || uv->buf_size < sizeof(*mhdr)) { + return UEFI_VARS_STS_ERR_BAD_BUFFER_SIZE; + } + + /* read header */ + if (dma_mode) { + dma_memory_read(&address_space_memory, dma, + uv->buffer, sizeof(*mhdr), + MEMTXATTRS_UNSPECIFIED); + } else { + memcpy(uv->buffer, uv->pio_xfer_buffer, sizeof(*mhdr)); + } + + if (uadd64_overflow(sizeof(*mhdr), mhdr->length, &size)) { + return UEFI_VARS_STS_ERR_BAD_BUFFER_SIZE; + } + if (uv->buf_size < size) { + return UEFI_VARS_STS_ERR_BAD_BUFFER_SIZE; + } + + /* read buffer (excl header) */ + if (dma_mode) { + dma_memory_read(&address_space_memory, dma + sizeof(*mhdr), + uv->buffer + sizeof(*mhdr), mhdr->length, + MEMTXATTRS_UNSPECIFIED); + } else { + memcpy(uv->buffer + sizeof(*mhdr), + uv->pio_xfer_buffer + sizeof(*mhdr), + mhdr->length); + } + memset(uv->buffer + size, 0, uv->buf_size - size); + + /* dispatch */ + if (qemu_uuid_is_equal(&mhdr->guid, &EfiSmmVariableProtocolGuid)) { + retval = uefi_vars_mm_vars_proto(uv); + + } else if (qemu_uuid_is_equal(&mhdr->guid, &VarCheckPolicyLibMmiHandlerGuid)) { + retval = uefi_vars_mm_check_policy_proto(uv); + + } else if (qemu_uuid_is_equal(&mhdr->guid, &EfiEndOfDxeEventGroupGuid)) { + trace_uefi_event("end-of-dxe"); + uv->end_of_dxe = true; + retval = UEFI_VARS_STS_SUCCESS; + + } else if (qemu_uuid_is_equal(&mhdr->guid, &EfiEventReadyToBootGuid)) { + trace_uefi_event("ready-to-boot"); + uv->ready_to_boot = true; + retval = UEFI_VARS_STS_SUCCESS; + + } else if (qemu_uuid_is_equal(&mhdr->guid, &EfiEventExitBootServicesGuid)) { + trace_uefi_event("exit-boot-service"); + uv->exit_boot_service = true; + retval = UEFI_VARS_STS_SUCCESS; + + } else { + retval = UEFI_VARS_STS_ERR_NOT_SUPPORTED; + } + + /* write buffer */ + if (dma_mode) { + dma_memory_write(&address_space_memory, dma, + uv->buffer, sizeof(*mhdr) + mhdr->length, + MEMTXATTRS_UNSPECIFIED); + } else { + memcpy(uv->pio_xfer_buffer + sizeof(*mhdr), + uv->buffer + sizeof(*mhdr), + sizeof(*mhdr) + mhdr->length); + } + + return retval; +} + +static void uefi_vars_soft_reset(uefi_vars_state *uv) +{ + g_free(uv->buffer); + uv->buffer = NULL; + uv->buf_size = 0; + uv->buf_addr_lo = 0; + uv->buf_addr_hi = 0; +} + +void uefi_vars_hard_reset(uefi_vars_state *uv) +{ + trace_uefi_hard_reset(); + uefi_vars_soft_reset(uv); + + uv->end_of_dxe = false; + uv->ready_to_boot = false; + uv->exit_boot_service = false; + uv->policy_locked = false; + + uefi_vars_clear_volatile(uv); + uefi_vars_policies_clear(uv); + uefi_vars_auth_init(uv); +} + +static uint32_t uefi_vars_cmd(uefi_vars_state *uv, uint32_t cmd) +{ + switch (cmd) { + case UEFI_VARS_CMD_RESET: + uefi_vars_soft_reset(uv); + return UEFI_VARS_STS_SUCCESS; + case UEFI_VARS_CMD_DMA_MM: + return uefi_vars_cmd_mm(uv, true); + case UEFI_VARS_CMD_PIO_MM: + return uefi_vars_cmd_mm(uv, false); + case UEFI_VARS_CMD_PIO_ZERO_OFFSET: + uv->pio_xfer_offset = 0; + return UEFI_VARS_STS_SUCCESS; + default: + return UEFI_VARS_STS_ERR_NOT_SUPPORTED; + } +} + +static uint64_t uefi_vars_read(void *opaque, hwaddr addr, unsigned size) +{ + uefi_vars_state *uv = opaque; + uint64_t retval = -1; + void *xfer_ptr; + + trace_uefi_reg_read(addr, size); + + switch (addr) { + case UEFI_VARS_REG_MAGIC: + retval = UEFI_VARS_MAGIC_VALUE; + break; + case UEFI_VARS_REG_CMD_STS: + retval = uv->sts; + break; + case UEFI_VARS_REG_BUFFER_SIZE: + retval = uv->buf_size; + break; + case UEFI_VARS_REG_DMA_BUFFER_ADDR_LO: + retval = uv->buf_addr_lo; + break; + case UEFI_VARS_REG_DMA_BUFFER_ADDR_HI: + retval = uv->buf_addr_hi; + break; + case UEFI_VARS_REG_PIO_BUFFER_TRANSFER: + if (uv->pio_xfer_offset + size > uv->buf_size) { + retval = 0; + break; + } + xfer_ptr = uv->pio_xfer_buffer + uv->pio_xfer_offset; + switch (size) { + case 1: + retval = *(uint8_t *)xfer_ptr; + break; + case 2: + retval = *(uint16_t *)xfer_ptr; + break; + case 4: + retval = *(uint32_t *)xfer_ptr; + break; + case 8: + retval = *(uint64_t *)xfer_ptr; + break; + } + uv->pio_xfer_offset += size; + break; + case UEFI_VARS_REG_PIO_BUFFER_CRC32C: + retval = crc32c(0xffffffff, uv->pio_xfer_buffer, uv->pio_xfer_offset); + break; + case UEFI_VARS_REG_FLAGS: + retval = 0; + if (uv->use_pio) { + retval |= UEFI_VARS_FLAG_USE_PIO; + } + } + return retval; +} + +static void uefi_vars_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) +{ + uefi_vars_state *uv = opaque; + void *xfer_ptr; + + trace_uefi_reg_write(addr, val, size); + + switch (addr) { + case UEFI_VARS_REG_CMD_STS: + uv->sts = uefi_vars_cmd(uv, val); + break; + case UEFI_VARS_REG_BUFFER_SIZE: + if (val > MAX_BUFFER_SIZE) { + val = MAX_BUFFER_SIZE; + } + uv->buf_size = val; + g_free(uv->buffer); + g_free(uv->pio_xfer_buffer); + uv->buffer = g_malloc(uv->buf_size); + uv->pio_xfer_buffer = g_malloc(uv->buf_size); + break; + case UEFI_VARS_REG_DMA_BUFFER_ADDR_LO: + uv->buf_addr_lo = val; + break; + case UEFI_VARS_REG_DMA_BUFFER_ADDR_HI: + uv->buf_addr_hi = val; + break; + case UEFI_VARS_REG_PIO_BUFFER_TRANSFER: + if (uv->pio_xfer_offset + size > uv->buf_size) { + break; + } + xfer_ptr = uv->pio_xfer_buffer + uv->pio_xfer_offset; + switch (size) { + case 1: + *(uint8_t *)xfer_ptr = val; + break; + case 2: + *(uint16_t *)xfer_ptr = val; + break; + case 4: + *(uint32_t *)xfer_ptr = val; + break; + case 8: + *(uint64_t *)xfer_ptr = val; + break; + } + uv->pio_xfer_offset += size; + break; + case UEFI_VARS_REG_PIO_BUFFER_CRC32C: + case UEFI_VARS_REG_FLAGS: + default: + break; + } +} + +static const MemoryRegionOps uefi_vars_ops = { + .read = uefi_vars_read, + .write = uefi_vars_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .impl = { + .min_access_size = 2, + .max_access_size = 4, + }, +}; + +void uefi_vars_init(Object *obj, uefi_vars_state *uv) +{ + QTAILQ_INIT(&uv->variables); + QTAILQ_INIT(&uv->var_policies); + uv->jsonfd = -1; + memory_region_init_io(&uv->mr, obj, &uefi_vars_ops, uv, + "uefi-vars", UEFI_VARS_REGS_SIZE); +} + +void uefi_vars_realize(uefi_vars_state *uv, Error **errp) +{ + uefi_vars_json_init(uv, errp); + uefi_vars_json_load(uv, errp); +} From 3e33af2cb306311d6fa4372c6d27489c165c1bd4 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:15 +0100 Subject: [PATCH 11/24] hw/uefi: add var-service-pkcs7.c This implements pkcs7 signature verification using gnutls. Needed to check authenticated variable updates. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-12-kraxel@redhat.com> --- hw/uefi/var-service-pkcs7.c | 436 ++++++++++++++++++++++++++++++++++++ 1 file changed, 436 insertions(+) create mode 100644 hw/uefi/var-service-pkcs7.c diff --git a/hw/uefi/var-service-pkcs7.c b/hw/uefi/var-service-pkcs7.c new file mode 100644 index 0000000000..32accf4e44 --- /dev/null +++ b/hw/uefi/var-service-pkcs7.c @@ -0,0 +1,436 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - pkcs7 verification + */ +#include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "system/dma.h" + +#include +#include +#include + +#include "hw/uefi/var-service.h" + +#define AUTHVAR_DIGEST_ALGO GNUTLS_DIG_SHA256 +#define AUTHVAR_DIGEST_SIZE 32 + +/* + * Replicate the signed data for signature verification. + */ +static gnutls_datum_t *build_signed_data(mm_variable_access *va, void *data) +{ + variable_auth_2 *auth = data; + uint64_t data_offset = sizeof(efi_time) + auth->hdr_length; + uint16_t *name = (void *)va + sizeof(mm_variable_access); + gnutls_datum_t *sdata; + uint64_t pos = 0; + + sdata = g_new(gnutls_datum_t, 1); + sdata->size = (va->name_size - 2 + + sizeof(QemuUUID) + + sizeof(va->attributes) + + sizeof(auth->timestamp) + + va->data_size - data_offset); + sdata->data = g_malloc(sdata->size); + + /* Variable Name (without terminating \0) */ + memcpy(sdata->data + pos, name, va->name_size - 2); + pos += va->name_size - 2; + + /* Variable Namespace Guid */ + memcpy(sdata->data + pos, &va->guid, sizeof(va->guid)); + pos += sizeof(va->guid); + + /* Attributes */ + memcpy(sdata->data + pos, &va->attributes, sizeof(va->attributes)); + pos += sizeof(va->attributes); + + /* TimeStamp */ + memcpy(sdata->data + pos, &auth->timestamp, sizeof(auth->timestamp)); + pos += sizeof(auth->timestamp); + + /* Variable Content */ + memcpy(sdata->data + pos, data + data_offset, va->data_size - data_offset); + pos += va->data_size - data_offset; + + assert(pos == sdata->size); + return sdata; +} + +/* + * See WrapPkcs7Data() in edk2. + * + * UEFI spec allows pkcs7 signatures being used without the envelope which + * identifies them as pkcs7 signatures. openssl and gnutls will not parse them + * without the envelope though. So add it if needed. + */ +static void wrap_pkcs7(gnutls_datum_t *pkcs7) +{ + static uint8_t signed_data_oid[9] = { + 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x07, 0x02 + }; + gnutls_datum_t wrap; + + if (pkcs7->data[4] == 0x06 && + pkcs7->data[5] == 0x09 && + memcmp(pkcs7->data + 6, signed_data_oid, sizeof(signed_data_oid)) == 0 && + pkcs7->data[15] == 0x0a && + pkcs7->data[16] == 0x82) { + return; + } + + wrap.size = pkcs7->size + 19; + wrap.data = g_malloc(wrap.size); + + wrap.data[0] = 0x30; + wrap.data[1] = 0x82; + wrap.data[2] = (wrap.size - 4) >> 8; + wrap.data[3] = (wrap.size - 4) & 0xff; + wrap.data[4] = 0x06; + wrap.data[5] = 0x09; + memcpy(wrap.data + 6, signed_data_oid, sizeof(signed_data_oid)); + + wrap.data[15] = 0xa0; + wrap.data[16] = 0x82; + wrap.data[17] = pkcs7->size >> 8; + wrap.data[18] = pkcs7->size & 0xff; + memcpy(wrap.data + 19, pkcs7->data, pkcs7->size); + + g_free(pkcs7->data); + *pkcs7 = wrap; +} + +static gnutls_datum_t *build_pkcs7(void *data) +{ + variable_auth_2 *auth = data; + gnutls_datum_t *pkcs7; + + pkcs7 = g_new(gnutls_datum_t, 1); + pkcs7->size = auth->hdr_length - 24; + pkcs7->data = g_malloc(pkcs7->size); + memcpy(pkcs7->data, data + 16 + 24, pkcs7->size); + + wrap_pkcs7(pkcs7); + + return pkcs7; +} + +/* + * Read UEFI signature database, store x509 all certificates found in + * gnutls_x509_trust_list_t. + */ +static gnutls_x509_trust_list_t build_trust_list_sb(uefi_variable *var) +{ + gnutls_x509_trust_list_t tlist; + gnutls_datum_t cert_data; + gnutls_x509_crt_t cert; + uefi_vars_siglist siglist; + uefi_vars_cert *c; + int rc; + + rc = gnutls_x509_trust_list_init(&tlist, 0); + if (rc < 0) { + warn_report("gnutls_x509_trust_list_init error: %s", + gnutls_strerror(rc)); + return NULL; + } + + uefi_vars_siglist_init(&siglist); + uefi_vars_siglist_parse(&siglist, var->data, var->data_size); + + QTAILQ_FOREACH(c, &siglist.x509, next) { + cert_data.size = c->size; + cert_data.data = c->data; + + rc = gnutls_x509_crt_init(&cert); + if (rc < 0) { + warn_report("gnutls_x509_crt_init error: %s", gnutls_strerror(rc)); + break; + } + rc = gnutls_x509_crt_import(cert, &cert_data, GNUTLS_X509_FMT_DER); + if (rc < 0) { + warn_report("gnutls_x509_crt_import error: %s", + gnutls_strerror(rc)); + gnutls_x509_crt_deinit(cert); + break; + } + rc = gnutls_x509_trust_list_add_cas(tlist, &cert, 1, 0); + if (rc < 0) { + warn_report("gnutls_x509_crt_import error: %s", + gnutls_strerror(rc)); + gnutls_x509_crt_deinit(cert); + break; + } + } + + uefi_vars_siglist_free(&siglist); + + return tlist; +} + +static int build_digest_authvar(gnutls_x509_crt_t signer, + gnutls_x509_crt_t root, + uint8_t *hash_digest) +{ + char *cn; + size_t cn_size = 0; + uint8_t fp[AUTHVAR_DIGEST_SIZE]; + size_t fp_size = sizeof(fp); + gnutls_hash_hd_t hash; + int rc; + + /* get signer CN */ + rc = gnutls_x509_crt_get_dn_by_oid(signer, GNUTLS_OID_X520_COMMON_NAME, + 0, 0, NULL, &cn_size); + if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) { + warn_report("gnutls_x509_crt_get_dn_by_oid error #1: %s", + gnutls_strerror(rc)); + return rc; + } + + cn = g_malloc(cn_size); + rc = gnutls_x509_crt_get_dn_by_oid(signer, GNUTLS_OID_X520_COMMON_NAME, + 0, 0, cn, &cn_size); + if (rc < 0) { + warn_report("gnutls_x509_crt_get_dn_by_oid error #2: %s", + gnutls_strerror(rc)); + goto err; + } + + /* get root certificate fingerprint */ + rc = gnutls_x509_crt_get_fingerprint(root, AUTHVAR_DIGEST_ALGO, + fp, &fp_size); + if (rc < 0) { + warn_report("gnutls_x509_crt_get_fingerprint error: %s", + gnutls_strerror(rc)); + goto err; + } + + /* digest both items */ + rc = gnutls_hash_init(&hash, AUTHVAR_DIGEST_ALGO); + if (rc < 0) { + warn_report("gnutls_hash_init error: %s", + gnutls_strerror(rc)); + goto err; + } + rc = gnutls_hash(hash, cn, cn_size); + if (rc < 0) { + warn_report("gnutls_hash error: %s", + gnutls_strerror(rc)); + goto err; + } + rc = gnutls_hash(hash, fp, fp_size); + if (rc < 0) { + warn_report("gnutls_hash error: %s", + gnutls_strerror(rc)); + goto err; + } + gnutls_hash_deinit(hash, hash_digest); + + return 0; + +err: + g_free(cn); + return rc; +} + +/* + * uefi spec 2.9, section 8.2.2 + * + * For EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS variables which are + * NOT secure boot variables we should track the root certificate of the trust + * chain, and the subject CN of the signer certificate. + * + * So we'll go store a digest of these two items so we can verify this. Also + * create a gnutls_x509_trust_list_t with the root certificate, so + * gnutls_pkcs7_verify() will pass (assuming the signature is otherwise + * correct). + */ +static gnutls_x509_trust_list_t build_trust_list_authvar(gnutls_pkcs7_t pkcs7, + uint8_t *hash_digest) +{ + gnutls_datum_t signer_data = { 0 }; + gnutls_datum_t root_data = { 0 }; + gnutls_x509_crt_t signer = NULL; + gnutls_x509_crt_t root = NULL; + gnutls_x509_trust_list_t tlist = NULL; + int n, rc; + + n = gnutls_pkcs7_get_crt_count(pkcs7); + + /* first is signer certificate */ + rc = gnutls_pkcs7_get_crt_raw2(pkcs7, 0, &signer_data); + if (rc < 0) { + warn_report("gnutls_pkcs7_get_crt_raw2(0) error: %s", + gnutls_strerror(rc)); + goto done; + } + rc = gnutls_x509_crt_init(&signer); + if (rc < 0) { + warn_report("gnutls_x509_crt_init error: %s", gnutls_strerror(rc)); + goto done; + } + rc = gnutls_x509_crt_import(signer, &signer_data, GNUTLS_X509_FMT_DER); + if (rc < 0) { + warn_report("gnutls_x509_crt_import error: %s", + gnutls_strerror(rc)); + gnutls_x509_crt_deinit(signer); + goto done; + } + + /* last is root-of-trust certificate (can be identical to signer) */ + rc = gnutls_pkcs7_get_crt_raw2(pkcs7, n - 1, &root_data); + if (rc < 0) { + warn_report("gnutls_pkcs7_get_crt_raw2(%d) error: %s", + n - 1, gnutls_strerror(rc)); + goto done; + } + rc = gnutls_x509_crt_init(&root); + if (rc < 0) { + warn_report("gnutls_x509_crt_init error: %s", gnutls_strerror(rc)); + goto done; + } + rc = gnutls_x509_crt_import(root, &root_data, GNUTLS_X509_FMT_DER); + if (rc < 0) { + warn_report("gnutls_x509_crt_import error: %s", + gnutls_strerror(rc)); + goto done; + } + + /* calc digest for signer CN + root cert */ + rc = build_digest_authvar(signer, root, hash_digest); + if (rc < 0) { + goto done; + } + + /* add root to trust list */ + rc = gnutls_x509_trust_list_init(&tlist, 0); + if (rc < 0) { + warn_report("gnutls_x509_trust_list_init error: %s", + gnutls_strerror(rc)); + goto done; + } + rc = gnutls_x509_trust_list_add_cas(tlist, &root, 1, 0); + if (rc < 0) { + warn_report("gnutls_x509_crt_import error: %s", + gnutls_strerror(rc)); + gnutls_x509_trust_list_deinit(tlist, 1); + tlist = NULL; + goto done; + } else { + /* ownership passed to tlist */ + root = NULL; + } + +done: + if (signer_data.data) { + gnutls_free(signer_data.data); + } + if (root_data.data) { + gnutls_free(root_data.data); + } + if (signer) { + gnutls_x509_crt_deinit(signer); + } + if (root) { + gnutls_x509_crt_deinit(root); + } + return tlist; +} + +static void free_datum(gnutls_datum_t *ptr) +{ + if (!ptr) { + return; + } + g_free(ptr->data); + g_free(ptr); +} + +static void gnutls_log_stderr(int level, const char *msg) +{ + if (strncmp(msg, "ASSERT:", 7) == 0) { + return; + } + fprintf(stderr, " %d: %s", level, msg); +} + +/* + * pkcs7 signature verification (EFI_VARIABLE_AUTHENTICATION_2). + */ +efi_status uefi_vars_check_pkcs7_2(uefi_variable *siglist, + void **digest, uint32_t *digest_size, + mm_variable_access *va, void *data) +{ + gnutls_x509_trust_list_t tlist = NULL; + gnutls_datum_t *signed_data = NULL; + gnutls_datum_t *pkcs7_data = NULL; + gnutls_pkcs7_t pkcs7 = NULL; + efi_status status = EFI_SECURITY_VIOLATION; + int rc; + + if (0) { + /* gnutls debug logging */ + static bool first = true; + + if (first) { + first = false; + gnutls_global_set_log_function(gnutls_log_stderr); + gnutls_global_set_log_level(99); + } + } + + signed_data = build_signed_data(va, data); + pkcs7_data = build_pkcs7(data); + + rc = gnutls_pkcs7_init(&pkcs7); + if (rc < 0) { + warn_report("gnutls_pkcs7_init error: %s", gnutls_strerror(rc)); + goto out; + } + + rc = gnutls_pkcs7_import(pkcs7, pkcs7_data, GNUTLS_X509_FMT_DER); + if (rc < 0) { + warn_report("gnutls_pkcs7_import error: %s", gnutls_strerror(rc)); + goto out; + } + + if (siglist) { + /* secure boot variables */ + tlist = build_trust_list_sb(siglist); + } else if (digest && digest_size) { + /* other authenticated variables */ + *digest_size = AUTHVAR_DIGEST_SIZE; + *digest = g_malloc(*digest_size); + tlist = build_trust_list_authvar(pkcs7, *digest); + } else { + /* should not happen */ + goto out; + } + + rc = gnutls_pkcs7_verify(pkcs7, tlist, + NULL, 0, + 0, signed_data, + GNUTLS_VERIFY_DISABLE_TIME_CHECKS | + GNUTLS_VERIFY_DISABLE_TRUSTED_TIME_CHECKS); + if (rc < 0) { + warn_report("gnutls_pkcs7_verify error: %s", gnutls_strerror(rc)); + goto out; + } + + /* check passed */ + status = EFI_SUCCESS; + +out: + free_datum(signed_data); + free_datum(pkcs7_data); + if (tlist) { + gnutls_x509_trust_list_deinit(tlist, 1); + } + if (pkcs7) { + gnutls_pkcs7_deinit(pkcs7); + } + return status; +} From 4ec89b00d5bd4184455cf41af859ec08ed87d8e5 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:16 +0100 Subject: [PATCH 12/24] hw/uefi: add var-service-pkcs7-stub.c pkcs7 stub which is used in case gnutls is not available. It throws EFI_WRITE_PROTECTED errors unconditionally, so all authenticated variables are readonly for the guest. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-13-kraxel@redhat.com> --- hw/uefi/var-service-pkcs7-stub.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) create mode 100644 hw/uefi/var-service-pkcs7-stub.c diff --git a/hw/uefi/var-service-pkcs7-stub.c b/hw/uefi/var-service-pkcs7-stub.c new file mode 100644 index 0000000000..118cba446d --- /dev/null +++ b/hw/uefi/var-service-pkcs7-stub.c @@ -0,0 +1,16 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - pkcs7 stubs + */ +#include "qemu/osdep.h" +#include "system/dma.h" + +#include "hw/uefi/var-service.h" + +efi_status uefi_vars_check_pkcs7_2(uefi_variable *siglist, + void **digest, uint32_t *digest_size, + mm_variable_access *va, void *data) +{ + return EFI_WRITE_PROTECTED; +} From f903e88306adfcce3b80a512a222c8551718d719 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:17 +0100 Subject: [PATCH 13/24] hw/uefi: add var-service-siglist.c Functions to serialize and de-serialize EFI signature databases. This is needed to merge signature databases (happens in practice when appending dbx updates) and also to extract the certificates for pkcs7 signature verification. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-14-kraxel@redhat.com> --- hw/uefi/var-service-siglist.c | 212 ++++++++++++++++++++++++++++++++++ 1 file changed, 212 insertions(+) create mode 100644 hw/uefi/var-service-siglist.c diff --git a/hw/uefi/var-service-siglist.c b/hw/uefi/var-service-siglist.c new file mode 100644 index 0000000000..8948f1b784 --- /dev/null +++ b/hw/uefi/var-service-siglist.c @@ -0,0 +1,212 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - parse and generate efi signature databases + */ + +#include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "system/dma.h" + +#include "hw/uefi/var-service.h" + +/* + * Add x509 certificate to list (with duplicate check). + */ +static void uefi_vars_siglist_add_x509(uefi_vars_siglist *siglist, + QemuUUID *owner, + void *data, uint64_t size) +{ + uefi_vars_cert *c; + + QTAILQ_FOREACH(c, &siglist->x509, next) { + if (c->size != size) { + continue; + } + if (memcmp(c->data, data, size) != 0) { + continue; + } + return; + } + + c = g_malloc(sizeof(*c) + size); + c->owner = *owner; + c->size = size; + memcpy(c->data, data, size); + QTAILQ_INSERT_TAIL(&siglist->x509, c, next); +} + +/* + * Add sha256 hash to list (with duplicate check). + */ +static void uefi_vars_siglist_add_sha256(uefi_vars_siglist *siglist, + QemuUUID *owner, + void *data) +{ + uefi_vars_hash *h; + + QTAILQ_FOREACH(h, &siglist->sha256, next) { + if (memcmp(h->data, data, 32) != 0) { + continue; + } + return; + } + + h = g_malloc(sizeof(*h) + 32); + h->owner = *owner; + memcpy(h->data, data, 32); + QTAILQ_INSERT_TAIL(&siglist->sha256, h, next); +} + +void uefi_vars_siglist_init(uefi_vars_siglist *siglist) +{ + memset(siglist, 0, sizeof(*siglist)); + QTAILQ_INIT(&siglist->x509); + QTAILQ_INIT(&siglist->sha256); +} + +void uefi_vars_siglist_free(uefi_vars_siglist *siglist) +{ + uefi_vars_cert *c, *cs; + uefi_vars_hash *h, *hs; + + QTAILQ_FOREACH_SAFE(c, &siglist->x509, next, cs) { + QTAILQ_REMOVE(&siglist->x509, c, next); + g_free(c); + } + QTAILQ_FOREACH_SAFE(h, &siglist->sha256, next, hs) { + QTAILQ_REMOVE(&siglist->sha256, h, next); + g_free(h); + } +} + +/* + * Parse UEFI signature list. + */ +void uefi_vars_siglist_parse(uefi_vars_siglist *siglist, + void *data, uint64_t size) +{ + efi_siglist *efilist; + uint64_t start; + + while (size) { + if (size < sizeof(*efilist)) { + break; + } + efilist = data; + if (size < efilist->siglist_size) { + break; + } + + if (uadd64_overflow(sizeof(*efilist), efilist->header_size, &start)) { + break; + } + if (efilist->sig_size <= sizeof(QemuUUID)) { + break; + } + + if (qemu_uuid_is_equal(&efilist->guid_type, &EfiCertX509Guid)) { + if (start + efilist->sig_size != efilist->siglist_size) { + break; + } + uefi_vars_siglist_add_x509(siglist, + (QemuUUID *)(data + start), + data + start + sizeof(QemuUUID), + efilist->sig_size - sizeof(QemuUUID)); + + } else if (qemu_uuid_is_equal(&efilist->guid_type, &EfiCertSha256Guid)) { + if (efilist->sig_size != sizeof(QemuUUID) + 32) { + break; + } + if (start + efilist->sig_size > efilist->siglist_size) { + break; + } + while (start <= efilist->siglist_size - efilist->sig_size) { + uefi_vars_siglist_add_sha256(siglist, + (QemuUUID *)(data + start), + data + start + sizeof(QemuUUID)); + start += efilist->sig_size; + } + + } else { + QemuUUID be = qemu_uuid_bswap(efilist->guid_type); + char *str_uuid = qemu_uuid_unparse_strdup(&be); + warn_report("%s: unknown type (%s)", __func__, str_uuid); + g_free(str_uuid); + } + + data += efilist->siglist_size; + size -= efilist->siglist_size; + } +} + +uint64_t uefi_vars_siglist_blob_size(uefi_vars_siglist *siglist) +{ + uefi_vars_cert *c; + uefi_vars_hash *h; + uint64_t size = 0; + + QTAILQ_FOREACH(c, &siglist->x509, next) { + size += sizeof(efi_siglist) + sizeof(QemuUUID) + c->size; + } + + if (!QTAILQ_EMPTY(&siglist->sha256)) { + size += sizeof(efi_siglist); + QTAILQ_FOREACH(h, &siglist->sha256, next) { + size += sizeof(QemuUUID) + 32; + } + } + + return size; +} + +/* + * Generate UEFI signature list. + */ +void uefi_vars_siglist_blob_generate(uefi_vars_siglist *siglist, + void *data, uint64_t size) +{ + uefi_vars_cert *c; + uefi_vars_hash *h; + efi_siglist *efilist; + uint64_t pos = 0, start; + uint32_t i; + + QTAILQ_FOREACH(c, &siglist->x509, next) { + efilist = data + pos; + efilist->guid_type = EfiCertX509Guid; + efilist->sig_size = sizeof(QemuUUID) + c->size; + efilist->header_size = 0; + + start = pos + sizeof(efi_siglist); + memcpy(data + start, + &c->owner, sizeof(QemuUUID)); + memcpy(data + start + sizeof(QemuUUID), + c->data, c->size); + + efilist->siglist_size = sizeof(efi_siglist) + efilist->sig_size; + pos += efilist->siglist_size; + } + + if (!QTAILQ_EMPTY(&siglist->sha256)) { + efilist = data + pos; + efilist->guid_type = EfiCertSha256Guid; + efilist->sig_size = sizeof(QemuUUID) + 32; + efilist->header_size = 0; + + i = 0; + start = pos + sizeof(efi_siglist); + QTAILQ_FOREACH(h, &siglist->sha256, next) { + memcpy(data + start + efilist->sig_size * i, + &h->owner, sizeof(QemuUUID)); + memcpy(data + start + efilist->sig_size * i + sizeof(QemuUUID), + h->data, 32); + i++; + } + + efilist->siglist_size = sizeof(efi_siglist) + efilist->sig_size * i; + pos += efilist->siglist_size; + } + + assert(pos == size); +} From 12058948abdf7eed8364aee79add66b40002fd5b Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:18 +0100 Subject: [PATCH 14/24] hw/uefi: add var-service-json.c + qapi for NV vars. Define qapi schema for the uefi variable store state. Use it and the generated visitor helper functions to store persistent (EFI_VARIABLE_NON_VOLATILE) variables in JSON format on disk. Acked-by: Markus Armbruster Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-15-kraxel@redhat.com> [ incremental fix squashed in ] Message-ID: --- hw/uefi/var-service-json.c | 243 +++++++++++++++++++++++++++++++++++++ qapi/meson.build | 1 + qapi/qapi-schema.json | 1 + qapi/uefi.json | 64 ++++++++++ 4 files changed, 309 insertions(+) create mode 100644 hw/uefi/var-service-json.c create mode 100644 qapi/uefi.json diff --git a/hw/uefi/var-service-json.c b/hw/uefi/var-service-json.c new file mode 100644 index 0000000000..761082c11f --- /dev/null +++ b/hw/uefi/var-service-json.c @@ -0,0 +1,243 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - serialize non-volatile varstore from/to json, + * using qapi + * + * tools which can read/write these json files: + * - https://gitlab.com/kraxel/virt-firmware + * - https://github.com/awslabs/python-uefivars + */ +#include "qemu/osdep.h" +#include "qemu/cutils.h" +#include "qemu/error-report.h" +#include "system/dma.h" + +#include "hw/uefi/var-service.h" + +#include "qobject/qobject.h" +#include "qobject/qjson.h" + +#include "qapi/dealloc-visitor.h" +#include "qapi/qobject-input-visitor.h" +#include "qapi/qobject-output-visitor.h" +#include "qapi/qapi-types-uefi.h" +#include "qapi/qapi-visit-uefi.h" + +static char *generate_hexstr(void *data, size_t len) +{ + static const char hex[] = { + '0', '1', '2', '3', '4', '5', '6', '7', + '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', + }; + uint8_t *src = data; + char *dest; + size_t i; + + dest = g_malloc(len * 2 + 1); + for (i = 0; i < len * 2;) { + dest[i++] = hex[*src >> 4]; + dest[i++] = hex[*src & 15]; + src++; + } + dest[i++] = 0; + + return dest; +} + +static UefiVarStore *uefi_vars_to_qapi(uefi_vars_state *uv) +{ + UefiVarStore *vs; + UefiVariableList **tail; + UefiVariable *v; + QemuUUID be; + uefi_variable *var; + + vs = g_new0(UefiVarStore, 1); + vs->version = 2; + tail = &vs->variables; + + QTAILQ_FOREACH(var, &uv->variables, next) { + if (!(var->attributes & EFI_VARIABLE_NON_VOLATILE)) { + continue; + } + + v = g_new0(UefiVariable, 1); + be = qemu_uuid_bswap(var->guid); + v->guid = qemu_uuid_unparse_strdup(&be); + v->name = uefi_ucs2_to_ascii(var->name, var->name_size); + v->attr = var->attributes; + + v->data = generate_hexstr(var->data, var->data_size); + + if (var->attributes & + EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) { + v->time = generate_hexstr(&var->time, sizeof(var->time)); + if (var->digest && var->digest_size) { + v->digest = generate_hexstr(var->digest, var->digest_size); + } + } + + QAPI_LIST_APPEND(tail, v); + } + return vs; +} + +static unsigned parse_hexchar(char c) +{ + switch (c) { + case '0' ... '9': return c - '0'; + case 'a' ... 'f': return c - 'a' + 0xa; + case 'A' ... 'F': return c - 'A' + 0xA; + default: return 0; + } +} + +static void parse_hexstr(void *dest, char *src, int len) +{ + uint8_t *data = dest; + size_t i; + + for (i = 0; i < len; i += 2) { + *(data++) = + parse_hexchar(src[i]) << 4 | + parse_hexchar(src[i + 1]); + } +} + +static void uefi_vars_from_qapi(uefi_vars_state *uv, UefiVarStore *vs) +{ + UefiVariableList *item; + UefiVariable *v; + QemuUUID be; + uefi_variable *var; + uint8_t *data; + size_t i, len; + + for (item = vs->variables; item != NULL; item = item->next) { + v = item->value; + + var = g_new0(uefi_variable, 1); + var->attributes = v->attr; + qemu_uuid_parse(v->guid, &be); + var->guid = qemu_uuid_bswap(be); + + len = strlen(v->name); + var->name_size = len * 2 + 2; + var->name = g_malloc(var->name_size); + for (i = 0; i <= len; i++) { + var->name[i] = v->name[i]; + } + + len = strlen(v->data); + var->data_size = len / 2; + var->data = data = g_malloc(var->data_size); + parse_hexstr(var->data, v->data, len); + + if (v->time && strlen(v->time) == 32) { + parse_hexstr(&var->time, v->time, 32); + } + + if (v->digest) { + len = strlen(v->digest); + var->digest_size = len / 2; + var->digest = g_malloc(var->digest_size); + parse_hexstr(var->digest, v->digest, len); + } + + QTAILQ_INSERT_TAIL(&uv->variables, var, next); + } +} + +static GString *uefi_vars_to_json(uefi_vars_state *uv) +{ + UefiVarStore *vs = uefi_vars_to_qapi(uv); + QObject *qobj = NULL; + Visitor *v; + GString *gstr; + + v = qobject_output_visitor_new(&qobj); + if (visit_type_UefiVarStore(v, NULL, &vs, NULL)) { + visit_complete(v, &qobj); + } + visit_free(v); + qapi_free_UefiVarStore(vs); + + gstr = qobject_to_json_pretty(qobj, true); + qobject_unref(qobj); + + return gstr; +} + +void uefi_vars_json_init(uefi_vars_state *uv, Error **errp) +{ + if (uv->jsonfile) { + uv->jsonfd = qemu_create(uv->jsonfile, O_RDWR, 0666, errp); + } +} + +void uefi_vars_json_save(uefi_vars_state *uv) +{ + GString *gstr; + int rc; + + if (uv->jsonfd == -1) { + return; + } + + gstr = uefi_vars_to_json(uv); + + lseek(uv->jsonfd, 0, SEEK_SET); + rc = ftruncate(uv->jsonfd, 0); + if (rc != 0) { + warn_report("%s: ftruncate error", __func__); + } + rc = write(uv->jsonfd, gstr->str, gstr->len); + if (rc != gstr->len) { + warn_report("%s: write error", __func__); + } + fsync(uv->jsonfd); + + g_string_free(gstr, true); +} + +void uefi_vars_json_load(uefi_vars_state *uv, Error **errp) +{ + UefiVarStore *vs; + QObject *qobj; + Visitor *v; + char *str; + size_t len; + int rc; + + if (uv->jsonfd == -1) { + return; + } + + len = lseek(uv->jsonfd, 0, SEEK_END); + if (len == 0) { + return; + } + + str = g_malloc(len + 1); + lseek(uv->jsonfd, 0, SEEK_SET); + rc = read(uv->jsonfd, str, len); + if (rc != len) { + warn_report("%s: read error", __func__); + } + str[len] = 0; + + qobj = qobject_from_json(str, errp); + v = qobject_input_visitor_new(qobj); + visit_type_UefiVarStore(v, NULL, &vs, errp); + visit_free(v); + + if (!(*errp)) { + uefi_vars_from_qapi(uv, vs); + uefi_vars_update_storage(uv); + } + + qapi_free_UefiVarStore(vs); + qobject_unref(qobj); + g_free(str); +} diff --git a/qapi/meson.build b/qapi/meson.build index e7bc54e5d0..eadde4db30 100644 --- a/qapi/meson.build +++ b/qapi/meson.build @@ -65,6 +65,7 @@ if have_system 'pci', 'rocker', 'tpm', + 'uefi', ] endif if have_system or have_tools diff --git a/qapi/qapi-schema.json b/qapi/qapi-schema.json index b1581988e4..2877aff73d 100644 --- a/qapi/qapi-schema.json +++ b/qapi/qapi-schema.json @@ -81,3 +81,4 @@ { 'include': 'vfio.json' } { 'include': 'cryptodev.json' } { 'include': 'cxl.json' } +{ 'include': 'uefi.json' } diff --git a/qapi/uefi.json b/qapi/uefi.json new file mode 100644 index 0000000000..bdfcabe1df --- /dev/null +++ b/qapi/uefi.json @@ -0,0 +1,64 @@ +# -*- Mode: Python -*- +# vim: filetype=python +# + +## +# = UEFI Variable Store +# +# The qemu efi variable store implementation (hw/uefi/) uses this to +# store non-volatile variables in json format on disk. +# +# This is an existing format already supported by (at least) two other +# projects, specifically https://gitlab.com/kraxel/virt-firmware and +# https://github.com/awslabs/python-uefivars. +## + +## +# @UefiVariable: +# +# UEFI Variable. Check the UEFI specifification for more detailed +# information on the fields. +# +# @guid: variable namespace GUID +# +# @name: variable name, in UTF-8 encoding. +# +# @attr: variable attributes. +# +# @data: variable value, encoded as hex string. +# +# @time: variable modification time. EFI_TIME struct, encoded as hex +# string. Used only for authenticated variables, where the +# EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS attribute bit +# is set. +# +# @digest: variable certificate digest. Used to verify the signature +# of updates for authenticated variables. UEFI has two kinds of +# authenticated variables. The secure boot variables ('PK', +# 'KEK', 'db' and 'dbx') have hard coded signature checking rules. +# For other authenticated variables the firmware stores a digest +# of the signing certificate at variable creation time, and any +# updates must be signed with the same certificate. +# +# Since: 10.0 +## +{ 'struct' : 'UefiVariable', + 'data' : { 'guid' : 'str', + 'name' : 'str', + 'attr' : 'int', + 'data' : 'str', + '*time' : 'str', + '*digest' : 'str'}} + +## +# @UefiVarStore: +# +# @version: currently always 2 +# +# @variables: list of UEFI variables +# +# Since: 10.0 +## +{ 'struct' : 'UefiVarStore', + 'data' : { 'version' : 'int', + 'variables' : [ 'UefiVariable' ] }} From 9282bed590ab54a24659fdcff668d46d7129d946 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:19 +0100 Subject: [PATCH 15/24] hw/uefi: add trace-events Add trace events for debugging and trouble shooting. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-16-kraxel@redhat.com> --- hw/uefi/trace-events | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 hw/uefi/trace-events diff --git a/hw/uefi/trace-events b/hw/uefi/trace-events new file mode 100644 index 0000000000..3694712a94 --- /dev/null +++ b/hw/uefi/trace-events @@ -0,0 +1,17 @@ +# device +uefi_reg_read(uint64_t addr, unsigned size) "addr 0x%" PRIx64 ", size %u" +uefi_reg_write(uint64_t addr, uint64_t val, unsigned size) "addr 0x%" PRIx64 ", val 0x%" PRIx64 ", size %d" +uefi_hard_reset(void) "" + +# generic uefi +uefi_variable(const char *context, const char *name, uint64_t size, const char *uuid) "context %s, name %s, size %" PRIu64 ", uuid %s" +uefi_status(const char *context, const char *name) "context %s, status %s" +uefi_event(const char *name) "event %s" + +# variable protocol +uefi_vars_proto_cmd(const char *cmd) "cmd %s" +uefi_vars_security_violation(const char *reason) "reason %s" + +# variable policy protocol +uefi_vars_policy_cmd(const char *cmd) "cmd %s" +uefi_vars_policy_deny(const char *reason) "reason %s" From e8371973d7e651f9d7b82100cb9745fd2795d722 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:20 +0100 Subject: [PATCH 16/24] hw/uefi: add UEFI_VARS to Kconfig Add UEFI_VARS config option, enable by default for x86_64 and aarch64. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-17-kraxel@redhat.com> --- hw/Kconfig | 1 + hw/uefi/Kconfig | 3 +++ 2 files changed, 4 insertions(+) create mode 100644 hw/uefi/Kconfig diff --git a/hw/Kconfig b/hw/Kconfig index 1b4e9bb07f..c4dfe2e7af 100644 --- a/hw/Kconfig +++ b/hw/Kconfig @@ -37,6 +37,7 @@ source smbios/Kconfig source ssi/Kconfig source timer/Kconfig source tpm/Kconfig +source uefi/Kconfig source ufs/Kconfig source usb/Kconfig source virtio/Kconfig diff --git a/hw/uefi/Kconfig b/hw/uefi/Kconfig new file mode 100644 index 0000000000..ca6c2bc46a --- /dev/null +++ b/hw/uefi/Kconfig @@ -0,0 +1,3 @@ +config UEFI_VARS + bool + default y if X86_64 || AARCH64 From 736ca80cdd18c837dcfca016a6df746a70d33bb2 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:21 +0100 Subject: [PATCH 17/24] hw/uefi: add to meson Wire up uefi-vars in the build system. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-18-kraxel@redhat.com> --- hw/meson.build | 1 + hw/uefi/meson.build | 19 +++++++++++++++++++ meson.build | 1 + 3 files changed, 21 insertions(+) diff --git a/hw/meson.build b/hw/meson.build index b827c82c5d..138f5d59e1 100644 --- a/hw/meson.build +++ b/hw/meson.build @@ -35,6 +35,7 @@ subdir('smbios') subdir('ssi') subdir('timer') subdir('tpm') +subdir('uefi') subdir('ufs') subdir('usb') subdir('vfio') diff --git a/hw/uefi/meson.build b/hw/uefi/meson.build index a8b1689412..e63708aa16 100644 --- a/hw/uefi/meson.build +++ b/hw/uefi/meson.build @@ -1 +1,20 @@ system_ss.add(files('hardware-info.c')) + +uefi_vars_ss = ss.source_set() +if (config_all_devices.has_key('CONFIG_UEFI_VARS')) + uefi_vars_ss.add(files('var-service-core.c', + 'var-service-json.c', + 'var-service-vars.c', + 'var-service-auth.c', + 'var-service-guid.c', + 'var-service-utils.c', + 'var-service-policy.c')) + uefi_vars_ss.add(when: gnutls, + if_true: files('var-service-pkcs7.c'), + if_false: files('var-service-pkcs7-stub.c')) + uefi_vars_ss.add(files('var-service-siglist.c')) +endif + +modules += { 'hw-uefi' : { + 'vars' : uefi_vars_ss, +}} diff --git a/meson.build b/meson.build index 0a2c61d2bf..1c1982dac3 100644 --- a/meson.build +++ b/meson.build @@ -3601,6 +3601,7 @@ if have_system 'hw/ssi', 'hw/timer', 'hw/tpm', + 'hw/uefi', 'hw/ufs', 'hw/usb', 'hw/vfio', From 5bb89df2e37382d6d278d52cfb22ae61f60daf70 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:22 +0100 Subject: [PATCH 18/24] hw/uefi: add uefi-vars-sysbus device This adds sysbus bindings for the variable service. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-19-kraxel@redhat.com> --- hw/uefi/meson.build | 3 +- hw/uefi/var-service-sysbus.c | 91 ++++++++++++++++++++++++++++++++++++ 2 files changed, 93 insertions(+), 1 deletion(-) create mode 100644 hw/uefi/var-service-sysbus.c diff --git a/hw/uefi/meson.build b/hw/uefi/meson.build index e63708aa16..91eb95f89e 100644 --- a/hw/uefi/meson.build +++ b/hw/uefi/meson.build @@ -8,7 +8,8 @@ if (config_all_devices.has_key('CONFIG_UEFI_VARS')) 'var-service-auth.c', 'var-service-guid.c', 'var-service-utils.c', - 'var-service-policy.c')) + 'var-service-policy.c', + 'var-service-sysbus.c')) uefi_vars_ss.add(when: gnutls, if_true: files('var-service-pkcs7.c'), if_false: files('var-service-pkcs7-stub.c')) diff --git a/hw/uefi/var-service-sysbus.c b/hw/uefi/var-service-sysbus.c new file mode 100644 index 0000000000..60072c8815 --- /dev/null +++ b/hw/uefi/var-service-sysbus.c @@ -0,0 +1,91 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * uefi vars device - sysbus variant. + */ +#include "qemu/osdep.h" +#include "migration/vmstate.h" + +#include "hw/qdev-properties.h" +#include "hw/sysbus.h" + +#include "hw/uefi/var-service.h" +#include "hw/uefi/var-service-api.h" + +OBJECT_DECLARE_SIMPLE_TYPE(uefi_vars_sysbus_state, UEFI_VARS_SYSBUS) + +struct uefi_vars_sysbus_state { + SysBusDevice parent_obj; + struct uefi_vars_state state; +}; + +static const VMStateDescription vmstate_uefi_vars_sysbus = { + .name = TYPE_UEFI_VARS_SYSBUS, + .fields = (VMStateField[]) { + VMSTATE_STRUCT(state, uefi_vars_sysbus_state, 0, + vmstate_uefi_vars, uefi_vars_state), + VMSTATE_END_OF_LIST() + } +}; + +static const Property uefi_vars_sysbus_properties[] = { + DEFINE_PROP_SIZE("size", uefi_vars_sysbus_state, state.max_storage, + 256 * 1024), + DEFINE_PROP_STRING("jsonfile", uefi_vars_sysbus_state, state.jsonfile), + DEFINE_PROP_BOOL("force-secure-boot", uefi_vars_sysbus_state, + state.force_secure_boot, false), + DEFINE_PROP_BOOL("disable-custom-mode", uefi_vars_sysbus_state, + state.disable_custom_mode, false), + DEFINE_PROP_BOOL("use-pio", uefi_vars_sysbus_state, + state.use_pio, false), +}; + +static void uefi_vars_sysbus_init(Object *obj) +{ + uefi_vars_sysbus_state *uv = UEFI_VARS_SYSBUS(obj); + + uefi_vars_init(obj, &uv->state); +} + +static void uefi_vars_sysbus_reset(DeviceState *dev) +{ + uefi_vars_sysbus_state *uv = UEFI_VARS_SYSBUS(dev); + + uefi_vars_hard_reset(&uv->state); +} + +static void uefi_vars_sysbus_realize(DeviceState *dev, Error **errp) +{ + uefi_vars_sysbus_state *uv = UEFI_VARS_SYSBUS(dev); + SysBusDevice *sysbus = SYS_BUS_DEVICE(dev); + + sysbus_init_mmio(sysbus, &uv->state.mr); + uefi_vars_realize(&uv->state, errp); +} + +static void uefi_vars_sysbus_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = uefi_vars_sysbus_realize; + dc->vmsd = &vmstate_uefi_vars_sysbus; + device_class_set_legacy_reset(dc, uefi_vars_sysbus_reset); + device_class_set_props(dc, uefi_vars_sysbus_properties); + set_bit(DEVICE_CATEGORY_MISC, dc->categories); +} + +static const TypeInfo uefi_vars_sysbus_info = { + .name = TYPE_UEFI_VARS_SYSBUS, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(uefi_vars_sysbus_state), + .instance_init = uefi_vars_sysbus_init, + .class_init = uefi_vars_sysbus_class_init, +}; +module_obj(TYPE_UEFI_VARS_SYSBUS); + +static void uefi_vars_sysbus_register_types(void) +{ + type_register_static(&uefi_vars_sysbus_info); +} + +type_init(uefi_vars_sysbus_register_types) From 03223b665c675f6f7d05555d9c6a69678c9ab875 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:23 +0100 Subject: [PATCH 19/24] hw/uefi-vars-sysbus: qemu platform bus support Add and register function to create an device tree entry when the device is added to the qemu platform bus. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-20-kraxel@redhat.com> --- hw/core/sysbus-fdt.c | 24 ++++++++++++++++++++++++ hw/uefi/var-service-sysbus.c | 1 + 2 files changed, 25 insertions(+) diff --git a/hw/core/sysbus-fdt.c b/hw/core/sysbus-fdt.c index 774c0aed41..e85066b905 100644 --- a/hw/core/sysbus-fdt.c +++ b/hw/core/sysbus-fdt.c @@ -36,6 +36,7 @@ #include "hw/vfio/vfio-calxeda-xgmac.h" #include "hw/vfio/vfio-amd-xgbe.h" #include "hw/display/ramfb.h" +#include "hw/uefi/var-service-api.h" #include "hw/arm/fdt.h" /* @@ -471,6 +472,28 @@ static int add_tpm_tis_fdt_node(SysBusDevice *sbdev, void *opaque) } #endif +static int add_uefi_vars_node(SysBusDevice *sbdev, void *opaque) +{ + PlatformBusFDTData *data = opaque; + PlatformBusDevice *pbus = data->pbus; + const char *parent_node = data->pbus_node_name; + void *fdt = data->fdt; + uint64_t mmio_base; + char *nodename; + + mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, 0); + nodename = g_strdup_printf("%s/%s@%" PRIx64, parent_node, + UEFI_VARS_FDT_NODE, mmio_base); + qemu_fdt_add_subnode(fdt, nodename); + qemu_fdt_setprop_string(fdt, nodename, + "compatible", UEFI_VARS_FDT_COMPAT); + qemu_fdt_setprop_sized_cells(fdt, nodename, "reg", + 1, mmio_base, + 1, UEFI_VARS_REGS_SIZE); + g_free(nodename); + return 0; +} + static int no_fdt_node(SysBusDevice *sbdev, void *opaque) { return 0; @@ -495,6 +518,7 @@ static const BindingEntry bindings[] = { TYPE_BINDING(TYPE_TPM_TIS_SYSBUS, add_tpm_tis_fdt_node), #endif TYPE_BINDING(TYPE_RAMFB_DEVICE, no_fdt_node), + TYPE_BINDING(TYPE_UEFI_VARS_SYSBUS, add_uefi_vars_node), TYPE_BINDING("", NULL), /* last element */ }; diff --git a/hw/uefi/var-service-sysbus.c b/hw/uefi/var-service-sysbus.c index 60072c8815..28572981c2 100644 --- a/hw/uefi/var-service-sysbus.c +++ b/hw/uefi/var-service-sysbus.c @@ -69,6 +69,7 @@ static void uefi_vars_sysbus_class_init(ObjectClass *klass, void *data) dc->realize = uefi_vars_sysbus_realize; dc->vmsd = &vmstate_uefi_vars_sysbus; + dc->user_creatable = true; device_class_set_legacy_reset(dc, uefi_vars_sysbus_reset); device_class_set_props(dc, uefi_vars_sysbus_properties); set_bit(DEVICE_CATEGORY_MISC, dc->categories); From 69392de9138fe6d49f96dfae8adfb9cd64e0578e Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:24 +0100 Subject: [PATCH 20/24] hw/uefi-vars-sysbus: add x64 variant The x86 variant of the device is mapped on the fixed address 0xfef10000 and uses etc/hardware-info instead of FDT to pass the mapping location to the edk2 firmware. The latter allows to move the device to a different location should that turn out to be necessary in the future. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-21-kraxel@redhat.com> --- hw/uefi/var-service-sysbus.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/hw/uefi/var-service-sysbus.c b/hw/uefi/var-service-sysbus.c index 28572981c2..97da8672ee 100644 --- a/hw/uefi/var-service-sysbus.c +++ b/hw/uefi/var-service-sysbus.c @@ -9,6 +9,7 @@ #include "hw/qdev-properties.h" #include "hw/sysbus.h" +#include "hw/uefi/hardware-info.h" #include "hw/uefi/var-service.h" #include "hw/uefi/var-service-api.h" @@ -75,6 +76,7 @@ static void uefi_vars_sysbus_class_init(ObjectClass *klass, void *data) set_bit(DEVICE_CATEGORY_MISC, dc->categories); } +/* generic: hardware discovery via FDT */ static const TypeInfo uefi_vars_sysbus_info = { .name = TYPE_UEFI_VARS_SYSBUS, .parent = TYPE_SYS_BUS_DEVICE, @@ -84,9 +86,39 @@ static const TypeInfo uefi_vars_sysbus_info = { }; module_obj(TYPE_UEFI_VARS_SYSBUS); +static void uefi_vars_x64_realize(DeviceState *dev, Error **errp) +{ + HARDWARE_INFO_SIMPLE_DEVICE hwinfo = { + .mmio_address = cpu_to_le64(0xfef10000), + }; + SysBusDevice *sysbus = SYS_BUS_DEVICE(dev); + + uefi_vars_sysbus_realize(dev, errp); + + hardware_info_register(HardwareInfoQemuUefiVars, + &hwinfo, sizeof(hwinfo)); + sysbus_mmio_map(sysbus, 0, hwinfo.mmio_address); +} + +static void uefi_vars_x64_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = uefi_vars_x64_realize; +} + +/* x64: hardware discovery via etc/hardware-info fw_cfg */ +static const TypeInfo uefi_vars_x64_info = { + .name = TYPE_UEFI_VARS_X64, + .parent = TYPE_UEFI_VARS_SYSBUS, + .class_init = uefi_vars_x64_class_init, +}; +module_obj(TYPE_UEFI_VARS_X64); + static void uefi_vars_sysbus_register_types(void) { type_register_static(&uefi_vars_sysbus_info); + type_register_static(&uefi_vars_x64_info); } type_init(uefi_vars_sysbus_register_types) From 22ebb90e62e97a431ec50edf7ddb19412a934555 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:25 +0100 Subject: [PATCH 21/24] hw/uefi-vars-sysbus: allow for arm virt Allow the device being added to aarch64 virt VMs. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-22-kraxel@redhat.com> --- hw/arm/virt.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index ee69081ef4..904c698b14 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -82,6 +82,7 @@ #include "hw/mem/pc-dimm.h" #include "hw/mem/nvdimm.h" #include "hw/acpi/generic_event_device.h" +#include "hw/uefi/var-service-api.h" #include "hw/virtio/virtio-md-pci.h" #include "hw/virtio/virtio-iommu.h" #include "hw/char/pl011.h" @@ -3162,6 +3163,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data) machine_class_allow_dynamic_sysbus_dev(mc, TYPE_VFIO_AMD_XGBE); machine_class_allow_dynamic_sysbus_dev(mc, TYPE_RAMFB_DEVICE); machine_class_allow_dynamic_sysbus_dev(mc, TYPE_VFIO_PLATFORM); + machine_class_allow_dynamic_sysbus_dev(mc, TYPE_UEFI_VARS_SYSBUS); #ifdef CONFIG_TPM machine_class_allow_dynamic_sysbus_dev(mc, TYPE_TPM_TIS_SYSBUS); #endif From 918b8a12247090a03ac8db61ac19a97170a553df Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:26 +0100 Subject: [PATCH 22/24] hw/uefi-vars-sysbus: allow for pc and q35 Allow the device being added to x86_64 pc and q35 VMs. Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-23-kraxel@redhat.com> --- hw/i386/pc_piix.c | 2 ++ hw/i386/pc_q35.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 04d2957adc..6c91e2d292 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -65,6 +65,7 @@ #include "system/numa.h" #include "hw/hyperv/vmbus-bridge.h" #include "hw/mem/nvdimm.h" +#include "hw/uefi/var-service-api.h" #include "hw/i386/acpi-build.h" #include "target/i386/cpu.h" @@ -468,6 +469,7 @@ static void pc_i440fx_machine_options(MachineClass *m) m->no_parallel = !module_object_class_by_name(TYPE_ISA_PARALLEL); machine_class_allow_dynamic_sysbus_dev(m, TYPE_RAMFB_DEVICE); machine_class_allow_dynamic_sysbus_dev(m, TYPE_VMBUS_BRIDGE); + machine_class_allow_dynamic_sysbus_dev(m, TYPE_UEFI_VARS_X64); object_class_property_add_enum(oc, "x-south-bridge", "PCSouthBridgeOption", &PCSouthBridgeOption_lookup, diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index 77536dd697..fd96d0345c 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -58,6 +58,7 @@ #include "system/numa.h" #include "hw/hyperv/vmbus-bridge.h" #include "hw/mem/nvdimm.h" +#include "hw/uefi/var-service-api.h" #include "hw/i386/acpi-build.h" #include "target/i386/cpu.h" @@ -355,6 +356,7 @@ static void pc_q35_machine_options(MachineClass *m) machine_class_allow_dynamic_sysbus_dev(m, TYPE_INTEL_IOMMU_DEVICE); machine_class_allow_dynamic_sysbus_dev(m, TYPE_RAMFB_DEVICE); machine_class_allow_dynamic_sysbus_dev(m, TYPE_VMBUS_BRIDGE); + machine_class_allow_dynamic_sysbus_dev(m, TYPE_UEFI_VARS_X64); compat_props_add(m->compat_props, pc_q35_compat_defaults, pc_q35_compat_defaults_len); } From 06fa8ec6f656af28624ab2da20541ce5d6e8c18e Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:27 +0100 Subject: [PATCH 23/24] hw/uefi: add MAINTAINERS entry Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-24-kraxel@redhat.com> --- MAINTAINERS | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 2e7fc6fa91..27cdfbebdd 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2820,6 +2820,12 @@ F: hw/misc/ivshmem-flat.c F: include/hw/misc/ivshmem-flat.h F: docs/system/devices/ivshmem-flat.rst +UEFI variable service +M: Gerd Hoffmann +S: Maintained +F: hw/uefi/ +F: include/hw/uefi/ + Subsystems ---------- Overall Audio backends From 2bc10b15deb4b29391628e10b18701bfbcf4be17 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 25 Feb 2025 17:30:28 +0100 Subject: [PATCH 24/24] docs: add uefi variable service documentation Signed-off-by: Gerd Hoffmann Message-ID: <20250225163031.1409078-25-kraxel@redhat.com> --- docs/devel/index-internals.rst | 1 + docs/devel/uefi-vars.rst | 68 ++++++++++++++++++++++++++++++++++ hw/uefi/LIMITATIONS.md | 7 ++++ 3 files changed, 76 insertions(+) create mode 100644 docs/devel/uefi-vars.rst create mode 100644 hw/uefi/LIMITATIONS.md diff --git a/docs/devel/index-internals.rst b/docs/devel/index-internals.rst index bca597c658..7a0678cbdd 100644 --- a/docs/devel/index-internals.rst +++ b/docs/devel/index-internals.rst @@ -20,6 +20,7 @@ Details about QEMU's various subsystems including how to add features to them. s390-cpu-topology s390-dasd-ipl tracing + uefi-vars vfio-iommufd writing-monitor-commands virtio-backends diff --git a/docs/devel/uefi-vars.rst b/docs/devel/uefi-vars.rst new file mode 100644 index 0000000000..0151a26a0a --- /dev/null +++ b/docs/devel/uefi-vars.rst @@ -0,0 +1,68 @@ +============== +UEFI variables +============== + +Guest UEFI variable management +============================== + +The traditional approach for UEFI Variable storage in qemu guests is +to work as close as possible to physical hardware. That means +providing pflash as storage and leaving the management of variables +and flash to the guest. + +Secure boot support comes with the requirement that the UEFI variable +storage must be protected against direct access by the OS. All update +requests must pass the sanity checks. (Parts of) the firmware must +run with a higher privilege level than the OS so this can be enforced +by the firmware. On x86 this has been implemented using System +Management Mode (SMM) in qemu and kvm, which again is the same +approach taken by physical hardware. Only privileged code running in +SMM mode is allowed to access flash storage. + +Communication with the firmware code running in SMM mode works by +serializing the requests to a shared buffer, then trapping into SMM +mode via SMI. The SMM code processes the request, stores the reply in +the same buffer and returns. + +Host UEFI variable service +========================== + +Instead of running the privileged code inside the guest we can run it +on the host. The serialization protocol can be reused. The +communication with the host uses a virtual device, which essentially +configures the shared buffer location and size, and traps to the host +to process the requests. + +The ``uefi-vars`` device implements the UEFI virtual device. It comes +in ``uefi-vars-x86`` and ``uefi-vars-sysbus`` flavours. The device +reimplements the handlers needed, specifically +``EfiSmmVariableProtocol`` and ``VarCheckPolicyLibMmiHandler``. It +also consumes events (``EfiEndOfDxeEventGroup``, +``EfiEventReadyToBoot`` and ``EfiEventExitBootServices``). + +The advantage of the approach is that we do not need a special +privilege level for the firmware to protect itself, i.e. it does not +depend on SMM emulation on x64, which allows the removal of a bunch of +complex code for SMM emulation from the linux kernel +(CONFIG_KVM_SMM=n). It also allows support for secure boot on arm +without implementing secure world (el3) emulation in kvm. + +Of course there are also downsides. The added device increases the +attack surface of the host, and we are adding some code duplication +because we have to reimplement some edk2 functionality in qemu. + +usage on x86_64 +--------------- + +.. code:: + + qemu-system-x86_64 \ + -device uefi-vars-x86,jsonfile=/path/to/vars.json + +usage on aarch64 +---------------- + +.. code:: + + qemu-system-aarch64 -M virt \ + -device uefi-vars-sysbus,jsonfile=/path/to/vars.json diff --git a/hw/uefi/LIMITATIONS.md b/hw/uefi/LIMITATIONS.md new file mode 100644 index 0000000000..29308bd587 --- /dev/null +++ b/hw/uefi/LIMITATIONS.md @@ -0,0 +1,7 @@ +known issues and limitations +---------------------------- + +* works only on little endian hosts + - accessing structs in guest ram is done without endian conversion. +* works only for 64-bit guests + - UINTN is mapped to uint64_t, for 32-bit guests that would be uint32_t