From: Tom Lendacky <thomas.lenda...@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
Under SEV-ES, a VMMCALL intercept generates a #VC exception. VMGEXIT must
be used to allow the hypervisor to handle this intercept.
Cc: Jordan Justen <jordan.l.jus...@intel.com>
Cc: Laszlo Ersek <ler...@redhat.com>
Cc: Ard Biesheuvel <ard.biesheu...@arm.com>
Acked-by: Laszlo Ersek <ler...@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c | 48 ++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
index ddaa19c7bcb4..dbea9c1f6aff 100644
--- a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
+++ b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c
@@ -883,6 +883,50 @@ WbinvdExit (
return VmgExit (Ghcb, SVM_EXIT_WBINVD, 0, 0);
}
+/**
+ Handle a VMMCALL event.
+
+ Use the VMGEXIT instruction to handle a VMMCALL 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
+VmmCallExit (
+ IN OUT GHCB *Ghcb,
+ IN OUT EFI_SYSTEM_CONTEXT_X64 *Regs,
+ IN SEV_ES_INSTRUCTION_DATA *InstructionData
+ )
+{
+ UINT64 Status;
+
+ DecodeModRm (Regs, InstructionData);
+
+ Ghcb->SaveArea.Rax = Regs->Rax;
+ GhcbSetRegValid (Ghcb, GhcbRax);
+ Ghcb->SaveArea.Cpl = (UINT8) (Regs->Cs & 0x3);
+ GhcbSetRegValid (Ghcb, GhcbCpl);
+
+ Status = VmgExit (Ghcb, SVM_EXIT_VMMCALL, 0, 0);
+ if (Status != 0) {
+ return Status;
+ }
+
+ if (!GhcbIsRegValid (Ghcb, GhcbRax)) {
+ return UnsupportedExit (Ghcb, Regs, InstructionData);
+ }
+ Regs->Rax = Ghcb->SaveArea.Rax;
+
+ return 0;
+}
+
/**
Handle an MSR event.
@@ -1397,6 +1441,10 @@ VmgExitHandleVc (
NaeExit = MsrExit;
break;
+ case SVM_EXIT_VMMCALL:
+ NaeExit = VmmCallExit;
+ break;
+
case SVM_EXIT_WBINVD:
NaeExit = WbinvdExit;
break;
--
2.28.0
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#64198): https://edk2.groups.io/g/devel/message/64198
Mute This Topic: https://groups.io/mt/76166997/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
