BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
Under SEV-ES, a MSR_PROT intercept generates a #VC exception. VMGEXIT must be used to allow the hypervisor to handle this intercept. Add support to construct the required GHCB values to support an MSR_PROT NAE event. Parse the instruction that generated the #VC exception to determine whether it is RDMSR or WRMSR, setting the required register register values in the GHCB and creating the proper SW_EXIT_INFO1 value in the GHCB. Cc: Eric Dong <[email protected]> Cc: Ray Ni <[email protected]> Cc: Laszlo Ersek <[email protected]> Signed-off-by: Tom Lendacky <[email protected]> --- .../X64/ArchAMDSevVcHandler.c | 49 +++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchAMDSevVcHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchAMDSevVcHandler.c index 970ee8752253..6f91cfff5fc8 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchAMDSevVcHandler.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/X64/ArchAMDSevVcHandler.c @@ -294,6 +294,51 @@ UnsupportedExit ( return Status; } +STATIC +UINT64 +MsrExit ( + GHCB *Ghcb, + EFI_SYSTEM_CONTEXT_X64 *Regs, + SEV_ES_INSTRUCTION_DATA *InstructionData + ) +{ + UINT64 ExitInfo1, Status; + + ExitInfo1 = 0; + + switch (*(InstructionData->OpCodes + 1)) { + case 0x30: // WRMSR + ExitInfo1 = 1; + Ghcb->SaveArea.Rax = Regs->Rax; + GhcbSetRegValid (Ghcb, GhcbRax); + Ghcb->SaveArea.Rdx = Regs->Rdx; + GhcbSetRegValid (Ghcb, GhcbRdx); + /* Fallthrough */ + case 0x32: // RDMSR + Ghcb->SaveArea.Rcx = Regs->Rcx; + GhcbSetRegValid (Ghcb, GhcbRcx); + break; + default: + return UnsupportedExit (Ghcb, Regs, InstructionData); + } + + Status = VmgExit (Ghcb, SvmExitMsr, ExitInfo1, 0); + if (Status) { + return Status; + } + + if (!ExitInfo1) { + if (!GhcbIsRegValid (Ghcb, GhcbRax) || + !GhcbIsRegValid (Ghcb, GhcbRdx)) { + return UnsupportedExit (Ghcb, Regs, InstructionData); + } + Regs->Rax = Ghcb->SaveArea.Rax; + Regs->Rdx = Ghcb->SaveArea.Rdx; + } + + return 0; +} + #define IOIO_TYPE_STR (1 << 2) #define IOIO_TYPE_IN 1 #define IOIO_TYPE_INS (IOIO_TYPE_IN | IOIO_TYPE_STR) @@ -558,6 +603,10 @@ DoVcCommon ( NaeExit = IoioExit; break; + case SvmExitMsr: + NaeExit = MsrExit; + break; + default: NaeExit = UnsupportedExit; } -- 2.17.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#55254): https://edk2.groups.io/g/devel/message/55254 Mute This Topic: https://groups.io/mt/71687806/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
