tyler.durden
/
audk
mirror of https://github.com/acidanthera/audk.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

OvmfPkg/VmgExitLib: Add support for RDTSC NAE events 

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a RDTSC intercept generates a #VC exception. VMGEXIT must be
used to allow the hypervisor to handle this intercept.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Tom Lendacky 2020-08-12 15:21:38 -05:00 committed by mergify[bot]
parent 4de7047976
commit 68d18bef41
1 changed files with 43 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
View File

@ -1223,6 +1223,45 @@ CpuidExit (
return 0;
}
/**
Handle a RDTSC event.
Use the VMGEXIT instruction to handle a RDTSC event.
@param[in, out] Ghcb Pointer to the Guest-Hypervisor Communication
Block
@param[in, out] Regs x64 processor context
@param[in] InstructionData Instruction parsing context
@retval 0 Event handled successfully
@return New exception value to propagate
**/
STATIC
UINT64
RdtscExit (
IN OUT GHCB *Ghcb,
IN OUT EFI_SYSTEM_CONTEXT_X64 *Regs,
IN SEV_ES_INSTRUCTION_DATA *InstructionData
)
{
UINT64 Status;
Status = VmgExit (Ghcb, SVM_EXIT_RDTSC, 0, 0);
if (Status != 0) {
return Status;
}
if (!GhcbIsRegValid (Ghcb, GhcbRax) ||
!GhcbIsRegValid (Ghcb, GhcbRdx)) {
return UnsupportedExit (Ghcb, Regs, InstructionData);
}
Regs->Rax = Ghcb->SaveArea.Rax;
Regs->Rdx = Ghcb->SaveArea.Rdx;
return 0;
}
/**
Handle a #VC exception.
@ -1267,6 +1306,10 @@ VmgExitHandleVc (
ExitCode = Regs->ExceptionData;
switch (ExitCode) {
case SVM_EXIT_RDTSC:
NaeExit = RdtscExit;
break;
case SVM_EXIT_CPUID:
NaeExit = CpuidExit;
break;