From 9f7e0d0adee2fe9cf84d9458b98b2ee5db8d9e44 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Wed, 12 Aug 2020 15:21:39 -0500 Subject: [PATCH] OvmfPkg/VmgExitLib: Add support for MWAIT/MWAITX NAE events BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198 Under SEV-ES, a MWAIT/MWAITX intercept generates a #VC exception. VMGEXIT must be used to allow the hypervisor to handle this intercept. Cc: Jordan Justen Cc: Laszlo Ersek Cc: Ard Biesheuvel Acked-by: Laszlo Ersek Signed-off-by: Tom Lendacky Regression-tested-by: Laszlo Ersek --- OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c | 36 +++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c index 1e8b8ce424..a741b080dd 100644 --- a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c +++ b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c @@ -858,6 +858,38 @@ MmioExit ( return Status; } +/** + Handle a MWAIT event. + + Use the VMGEXIT instruction to handle a MWAIT 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 +MwaitExit ( + IN OUT GHCB *Ghcb, + IN OUT EFI_SYSTEM_CONTEXT_X64 *Regs, + IN SEV_ES_INSTRUCTION_DATA *InstructionData + ) +{ + DecodeModRm (Regs, InstructionData); + + Ghcb->SaveArea.Rax = Regs->Rax; + GhcbSetRegValid (Ghcb, GhcbRax); + Ghcb->SaveArea.Rcx = Regs->Rcx; + GhcbSetRegValid (Ghcb, GhcbRcx); + + return VmgExit (Ghcb, SVM_EXIT_MWAIT, 0, 0); +} + /** Handle a MONITOR event. @@ -1534,6 +1566,10 @@ VmgExitHandleVc ( NaeExit = MonitorExit; break; + case SVM_EXIT_MWAIT: + NaeExit = MwaitExit; + break; + case SVM_EXIT_NPF: NaeExit = MmioExit; break; -- 2.39.5