target-ppc: dump-guest-memory support

This patch add support for dumping guest memory using dump-guest-memory
monitor command.

Before patch:

(qemu) dump-guest-memory testcrash
this feature or command is not currently supported
(qemu)

After patch:

(qemu) dump-guest-memory testcrash
(qemu)

crash was able to read the file

crash> bt
PID: 0      TASK: c000000000c0d0d0  CPU: 0   COMMAND: "swapper/0"

 R0:  0000000028000084    R1:  c000000000cafa50    R2:  c000000000cb05b0
 R3:  0000000000000000    R4:  c000000000bc4cb0    R5:  0000000000000000
 R6:  001efe93b8000000    R7:  0000000000000000    R8:  0000000000000000
 R9:  b000000000001032    R10: 0000000000000001    R11: 0001eb2117e00d55
....
...

NOTE: Currently crash tools doesn't look at ELF notes in the dump on ppc64.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

include/elf.h

@@ -1359,6 +1359,9 @@ typedef struct elf64_shdr {
 #define NT_S390_TODPREG 0x303           /* s390 TOD programmable register */
 #define NT_S390_TODCMP  0x302           /* s390 TOD clock comparator register */
 #define NT_S390_TIMER   0x301           /* s390 timer register */
+#define NT_PPC_VMX       0x100          /* PowerPC Altivec/VMX registers */
+#define NT_PPC_SPE       0x101          /* PowerPC SPE/EVR registers */
+#define NT_PPC_VSX       0x102          /* PowerPC VSX registers */
 
 
 /* Note header in a PT_NOTE section */

target-ppc/Makefile.objs

@@ -2,7 +2,7 @@ obj-y += cpu-models.o
 obj-y += translate.o
 ifeq ($(CONFIG_SOFTMMU),y)
 obj-y += machine.o mmu_helper.o mmu-hash32.o
-obj-$(TARGET_PPC64) += mmu-hash64.o
+obj-$(TARGET_PPC64) += mmu-hash64.o arch_dump.o
 endif
 obj-$(CONFIG_KVM) += kvm.o kvm_ppc.o
 obj-$(call lnot,$(CONFIG_KVM)) += kvm-stub.o

target-ppc/arch_dump.c

@@ -0,0 +1,253 @@
+/*
+ * writing ELF notes for ppc64 arch
+ *
+ *
+ * Copyright IBM, Corp. 2013
+ *
+ * Authors:
+ * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "cpu.h"
+#include "elf.h"
+#include "exec/cpu-all.h"
+#include "sysemu/dump.h"
+#include "sysemu/kvm.h"
+
+struct PPC64UserRegStruct {
+    uint64_t gpr[32];
+    uint64_t nip;
+    uint64_t msr;
+    uint64_t orig_gpr3;
+    uint64_t ctr;
+    uint64_t link;
+    uint64_t xer;
+    uint64_t ccr;
+    uint64_t softe;
+    uint64_t trap;
+    uint64_t dar;
+    uint64_t dsisr;
+    uint64_t result;
+} QEMU_PACKED;
+
+struct PPC64ElfPrstatus {
+    char pad1[112];
+    struct PPC64UserRegStruct pr_reg;
+    uint64_t pad2[4];
+} QEMU_PACKED;
+
+
+struct PPC64ElfFpregset {
+    uint64_t fpr[32];
+    uint64_t fpscr;
+}  QEMU_PACKED;
+
+
+struct PPC64ElfVmxregset {
+    ppc_avr_t avr[32];
+    ppc_avr_t vscr;
+    union {
+        ppc_avr_t unused;
+        uint32_t value;
+    } vrsave;
+}  QEMU_PACKED;
+
+struct PPC64ElfVsxregset {
+    uint64_t vsr[32];
+}  QEMU_PACKED;
+
+struct PPC64ElfSperegset {
+    uint32_t evr[32];
+    uint64_t spe_acc;
+    uint32_t spe_fscr;
+}  QEMU_PACKED;
+
+typedef struct noteStruct {
+    Elf64_Nhdr hdr;
+    char name[5];
+    char pad3[3];
+    union {
+        struct PPC64ElfPrstatus  prstatus;
+        struct PPC64ElfFpregset  fpregset;
+        struct PPC64ElfVmxregset vmxregset;
+        struct PPC64ElfVsxregset vsxregset;
+        struct PPC64ElfSperegset speregset;
+    } contents;
+} QEMU_PACKED Note;
+
+
+static void ppc64_write_elf64_prstatus(Note *note, PowerPCCPU *cpu)
+{
+    int i;
+    uint64_t cr;
+    struct PPC64ElfPrstatus *prstatus;
+    struct PPC64UserRegStruct *reg;
+
+    note->hdr.n_type = cpu_to_be32(NT_PRSTATUS);
+
+    prstatus = &note->contents.prstatus;
+    memset(prstatus, 0, sizeof(*prstatus));
+    reg = &prstatus->pr_reg;
+
+    for (i = 0; i < 32; i++) {
+        reg->gpr[i] = cpu_to_be64(cpu->env.gpr[i]);
+    }
+    reg->nip = cpu_to_be64(cpu->env.nip);
+    reg->msr = cpu_to_be64(cpu->env.msr);
+    reg->ctr = cpu_to_be64(cpu->env.ctr);
+    reg->link = cpu_to_be64(cpu->env.lr);
+    reg->xer = cpu_to_be64(cpu_read_xer(&cpu->env));
+
+    cr = 0;
+    for (i = 0; i < 8; i++) {
+        cr |= (cpu->env.crf[i] & 15) << (4 * (7 - i));
+    }
+    reg->ccr = cpu_to_be64(cr);
+}
+
+static void ppc64_write_elf64_fpregset(Note *note, PowerPCCPU *cpu)
+{
+    int i;
+    struct PPC64ElfFpregset  *fpregset;
+
+    note->hdr.n_type = cpu_to_be32(NT_PRFPREG);
+
+    fpregset = &note->contents.fpregset;
+    memset(fpregset, 0, sizeof(*fpregset));
+
+    for (i = 0; i < 32; i++) {
+        fpregset->fpr[i] = cpu_to_be64(cpu->env.fpr[i]);
+    }
+    fpregset->fpscr = cpu_to_be64(cpu->env.fpscr);
+}
+
+static void ppc64_write_elf64_vmxregset(Note *note, PowerPCCPU *cpu)
+{
+    int i;
+    struct PPC64ElfVmxregset *vmxregset;
+
+    note->hdr.n_type = cpu_to_be32(NT_PPC_VMX);
+    vmxregset = &note->contents.vmxregset;
+    memset(vmxregset, 0, sizeof(*vmxregset));
+
+    for (i = 0; i < 32; i++) {
+        vmxregset->avr[i].u64[0] = cpu_to_be64(cpu->env.avr[i].u64[0]);
+        vmxregset->avr[i].u64[1] = cpu_to_be64(cpu->env.avr[i].u64[1]);
+    }
+    vmxregset->vscr.u32[3] = cpu_to_be32(cpu->env.vscr);
+}
+static void ppc64_write_elf64_vsxregset(Note *note, PowerPCCPU *cpu)
+{
+    int i;
+    struct PPC64ElfVsxregset *vsxregset;
+
+    note->hdr.n_type = cpu_to_be32(NT_PPC_VSX);
+    vsxregset = &note->contents.vsxregset;
+    memset(vsxregset, 0, sizeof(*vsxregset));
+
+    for (i = 0; i < 32; i++) {
+        vsxregset->vsr[i] = cpu_to_be64(cpu->env.vsr[i]);
+    }
+}
+static void ppc64_write_elf64_speregset(Note *note, PowerPCCPU *cpu)
+{
+    struct PPC64ElfSperegset *speregset;
+    note->hdr.n_type = cpu_to_be32(NT_PPC_SPE);
+    speregset = &note->contents.speregset;
+    memset(speregset, 0, sizeof(*speregset));
+
+    speregset->spe_acc = cpu_to_be64(cpu->env.spe_acc);
+    speregset->spe_fscr = cpu_to_be32(cpu->env.spe_fscr);
+}
+
+struct NoteFuncDescStruct {
+    int contents_size;
+    void (*note_contents_func)(Note *note, PowerPCCPU *cpu);
+} note_func[] = {
+    {sizeof(((Note *)0)->contents.prstatus),  ppc64_write_elf64_prstatus},
+    {sizeof(((Note *)0)->contents.fpregset),  ppc64_write_elf64_fpregset},
+    {sizeof(((Note *)0)->contents.vmxregset), ppc64_write_elf64_vmxregset},
+    {sizeof(((Note *)0)->contents.vsxregset), ppc64_write_elf64_vsxregset},
+    {sizeof(((Note *)0)->contents.speregset), ppc64_write_elf64_speregset},
+    { 0, NULL}
+};
+
+typedef struct NoteFuncDescStruct NoteFuncDesc;
+
+int cpu_get_dump_info(ArchDumpInfo *info,
+                      const struct GuestPhysBlockList *guest_phys_blocks)
+{
+    /*
+     * Currently only handling PPC64 big endian.
+     */
+    info->d_machine = EM_PPC64;
+    info->d_endian = ELFDATA2MSB;
+    info->d_class = ELFCLASS64;
+
+    return 0;
+}
+
+ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
+{
+    int name_size = 8; /* "CORE" or "QEMU" rounded */
+    size_t elf_note_size = 0;
+    int note_head_size;
+    NoteFuncDesc *nf;
+
+    if (class != ELFCLASS64) {
+        return -1;
+    }
+    assert(machine == EM_PPC64);
+
+    note_head_size = sizeof(Elf64_Nhdr);
+
+    for (nf = note_func; nf->note_contents_func; nf++) {
+        elf_note_size = elf_note_size + note_head_size + name_size +
+                        nf->contents_size;
+    }
+
+    return (elf_note_size) * nr_cpus;
+}
+
+static int ppc64_write_all_elf64_notes(const char *note_name,
+                                       WriteCoreDumpFunction f,
+                                       PowerPCCPU *cpu, int id,
+                                       void *opaque)
+{
+    Note note;
+    int ret = -1;
+    int note_size;
+    NoteFuncDesc *nf;
+
+    for (nf = note_func; nf->note_contents_func; nf++) {
+        note.hdr.n_namesz = cpu_to_be32(sizeof(note.name));
+        note.hdr.n_descsz = cpu_to_be32(nf->contents_size);
+        strncpy(note.name, note_name, sizeof(note.name));
+
+        (*nf->note_contents_func)(&note, cpu);
+
+        note_size = sizeof(note) - sizeof(note.contents) + nf->contents_size;
+        ret = f(&note, note_size, opaque);
+        if (ret < 0) {
+            return -1;
+        }
+    }
+    return 0;
+}
+
+int ppc64_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
+                               int cpuid, void *opaque)
+{
+    PowerPCCPU *cpu = POWERPC_CPU(cs);
+    return ppc64_write_all_elf64_notes("CORE", f, cpu, cpuid, opaque);
+}
+
+int ppc64_cpu_write_elf64_qemunote(WriteCoreDumpFunction f,
+                                   CPUState *cpu, void *opaque)
+{
+    return 0;
+}

target-ppc/cpu-qom.h

@@ -108,7 +108,10 @@ void ppc_cpu_dump_statistics(CPUState *cpu, FILE *f,
 hwaddr ppc_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
 int ppc_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
 int ppc_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
-
+int ppc64_cpu_write_elf64_qemunote(WriteCoreDumpFunction f,
+                                   CPUState *cpu, void *opaque);
+int ppc64_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
+                               int cpuid, void *opaque);
 #ifndef CONFIG_USER_ONLY
 extern const struct VMStateDescription vmstate_ppc_cpu;
 #endif

target-ppc/translate_init.c

@@ -8572,6 +8572,10 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
 #ifndef CONFIG_USER_ONLY
     cc->get_phys_page_debug = ppc_cpu_get_phys_page_debug;
     cc->vmsd = &vmstate_ppc_cpu;
+#if defined(TARGET_PPC64)
+    cc->write_elf64_note = ppc64_cpu_write_elf64_note;
+    cc->write_elf64_qemunote = ppc64_cpu_write_elf64_qemunote;
+#endif
 #endif
 
     cc->gdb_num_core_regs = 71;