The FillExchangeInfoDataSevEs() is only called for SEV-SNP guests, but
the name (and comment in MpLib.c) implies that it is also called for
SEV-ES guests. Rename the function to FillExchangeInfoDataSevSnp() to
avoid confusion.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
The SevSnpKnownInitApicId field within the MP_CPU_EXCHANGE_INFO structure
is not guaranteed to be zero when booting an SEV-ES guest. While the check
in SevSnpGetInitCpuNumber() is conditionally guarded by verifying if the
guest is an SEV-SNP guest, the check in SevEsGetApicId() is not similarly
guarded.
This lack of protection can cause SevEsGetApicId() to return to the wrong
location. If the value of the SevSnpKnownInitApicId field contains the
exact random value of 1, the guest will be treated as an SEV-SNP guest
rather than an SEV-ES guest and return to the wrong location in the code
which will lead to a crash.
Ensure that all SEV related fields in MP_CPU_EXCHANGE_INFO structure are
properly initialized, thus removing the need for guarding access to the
SevSnpKnownInitApicId field.
Fixes: dca5d26bc5 ("UefiCpuPkg/MpInitLib: Fix SNP AP creation when using known APIC IDs")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
A typical initial AP boot up will choose a CpuNumber based on the ApIndex
value that it gets back after a locked increment of the ApIndex value.
The ApIndex to APIC ID relationship is random, which is not an issue when
a broadcast INIT-SIPI is performed.
With SNP and a hypervisor that supports retrieval of the known APIC IDs,
the broadcast INIT-SIPI method is replaced by waking each individual vCPU.
In this situation, a specific VMSA is associated with a specific APIC ID.
However, random assignment of an ApIndex can break this association. This
isn't typically an issue, because the AP bring-up finishes with the AP
issuing a HLT instruction, which is intercepted by the hypervisor and the
AP won't run again until the next INIT-SIPI. However, when HLT isn't
intercepted by the hypervisor (Qemu '-overcommit cpu-pm=on' parameter),
then the HLT does not exit to the hypervisor. On the next INIT-SIPI, it
can happen that a VMRUN is executed with a different VMSA address than
was originally used, and if that VMSA is still in a VMRUN on another AP,
then the executing VMRUN will fail, crashing the guest.
To fix this issue, add a CPU exchange info field, SevSnpKnownInitApicId,
that indicates the APs are starting with an already known initial APIC ID
and set the initial APIC ID and APIC ID in the CPU_INFO_IN_HOB HOB.
During AP boot, the SevSnpKnownInitApicId field will result in the
CpuNumber being set to the index with a matching APIC ID (similar to AP
booting when the InitFlag != ApInitConfig).
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Resolves several issues in UefiCpuPkg related to:
1. Unchecked returns leading to potential NULL or uninitialized access.
2. Potential unchecked integer overflows.
3. Incorrect comparison between integers of different sizes.
Co-authored-by: kenlautner <85201046+kenlautner@users.noreply.github.com>
Signed-off-by: Chris Fernald <chfernal@microsoft.com>
The CPUID_EXTENDED_TOPOLOGY CPUID leaf takes a subleaf as input when
returning CPUID information. However, the AsmCpuid() function does not
zero out ECX before the CPUID instruction, so the input leaf is used as
the sub-leaf for the CPUID request and returns erroneous/invalid CPUID
data, since the intent of the request was to get data related to sub-leaf
0. Instead, use AsmCpuidEx() for the CPUID_EXTENDED_TOPOLOGY leaf.
Fixes: d4d7c9ad5f ("UefiCpuPkg/MpInitLib: use BSP to do extended ...")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Initially, the purpose of the Hob was twofold: it served as a way to
transfer information from PEI to DXE. However, during the DXE phase,
only a few fields from the CPU_MP_DATA which collected in PEI phase were
needed. A new Hob was specifically created to transfer information
to the DXE phase. This new Hob contained only the essential fields
required for reuse in DXE. For instance, instead of directly including
the BspNumber in MpHandOff, the DXE phase introduced the use of
GetBspNumber() to collect the BspNumber from ApicID and CpuCount.
The SaveCpuMpData() function was updated to construct the MP_HAND_OFF
Hob. Additionally, the function introduced the MP_HAND_OFF_SIGNAL,
which solely served the purpose of awakening the APs
and transitioning their context from PEI to DXE. The
WaitLoopExecutionMode field indicated whether the bit mode of PEI
matched that of DXE. Both of them were filled only if the ApLoopMode
was not ApInHltLoop. In the case of ApInHltLoop, it remained necessary
to wake up the APs using the init-sipi-sipi sequence. This improvement
still allow INIT-SIPI-SIPI even APs are wait in Run/Mwait loop mode.
The function GetMpHandOffHob() was added to facilitate access to the
collected MpHandOff in the DXE phase. The CpuMpData in the DXE phase
was updated by gathering information from MpHandOff. Since MpHandOff
replaced the usage of OldCpuMpData and contained essential information
from the PEI phase to the DXE phase. AmdSevUpdateCpuMpData was included
to maintain the original implementation of AmdSev, ensuring that
OldCpuMpData->NewCpuMpData pointed to CpuMpData.
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4123
APIs which are defined in CcExitLib.h are added with the CcExit prefix.
This is to make the APIs' name more meaningful.
This change impacts OvmfPkg/UefiCpuPkg.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4123
VmgExitLib once was designed to provide interfaces to support #VC handler
and issue VMGEXIT instruction. After TDVF (enable TDX feature in OVMF) is
introduced, this library is updated to support #VE as well. Now the name
of VmgExitLib cannot reflect what the lib does.
This patch renames VmgExitLib to CcExitLib (Cc means Confidential
Computing). This is a simple renaming and there is no logic changes.
After renaming all the VmgExitLib related codes are updated with
CcExitLib. These changes are in OvmfPkg/UefiCpuPkg/UefiPayloadPkg.
Cc: Guo Dong <guo.dong@intel.com>
Cc: Sean Rhodes <sean@starlabs.systems>
Cc: James Lu <james.lu@intel.com>
Cc: Gua Guo <gua.guo@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: James Lu <james.lu@intel.com>
Reviewed-by: Gua Guo <gua.guo@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Today's implementation allocates below 1MB memory for the 16bit, 32bit
and 64bit code.
But it's not necessary since now the 32bit and 64bit code run at high
memory no matter in PEI and DXE phase.
The patch simplifies the logic to remove the code that handles the
case when WakeupBufferHigh is 0.
It also reduce the memory foot print under 1MB by allocating
memory for 16bit code only.
MP_CPU_EXCHANGE_INFO is still under 1MB which is immediate
after the 16bit code.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
During AP bringup, just after switching to long mode, APs will do some
cpuid calls to verify that the extended topology leaf (0xB) is available
so they can fetch their x2 APIC IDs from it. In the case of SEV-ES,
these cpuid instructions must be handled by direct use of the GHCB MSR
protocol to fetch the values from the hypervisor, since a #VC handler
is not yet available due to the AP's stack not being set up yet.
For SEV-SNP, rather than relying on the GHCB MSR protocol, it is
expected that these values would be obtained from the SEV-SNP CPUID
table instead. The actual x2 APIC ID (and 8-bit APIC IDs) would still
be fetched from hypervisor using the GHCB MSR protocol however, so
introducing support for the SEV-SNP CPUID table in that part of the AP
bring-up code would only be to handle the checks/validation of the
extended topology leaf.
Rather than introducing all the added complexity needed to handle these
checks via the CPUID table, instead let the BSP do the check in advance,
since it can make use of the #VC handler to avoid the need to scan the
SNP CPUID table directly, and add a flag in ExchangeInfo to communicate
the result of this check to APs.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Ray Ni <ray.ni@intel.com>
Suggested-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
Move all the SEV specific function in AmdSev.c.
No functional change intended.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Suggested-by: Jiewen Yao <Jiewen.yao@intel.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
