On 5/22/20 9:19 AM, Laszlo Ersek wrote:
On 05/19/20 23:50, Lendacky, Thomas wrote:
BZ:
https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D2198&data=02%7C01%7Cthomas.lendacky%40amd.com%7Cfc8d0918a2474d08139808d7fe5b2a93%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637257539824804827&sdata=aiIeMfwp9GQCrgqOw2si6NzLZOZzRRV%2Bzu3dpT6S%2F5k%3D&reserved=0
Under SEV-ES, a WBINVD 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>
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
.../Library/VmgExitLib/X64/VmgExitVcHandler.c | 36 +++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c
b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c
index 50199845ceef..0cf26c052b32 100644
--- a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c
+++ b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c
@@ -843,6 +843,38 @@ MmioExit (
return Status;
}
+/**
+ Handle a WBINVD event.
+
+ Use the VMGEXIT instruction to handle a WBINVD 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
+ @retval Others New exception value to propagate
+
+**/
+STATIC
+UINT64
+WbinvdExit (
+ IN OUT GHCB *Ghcb,
+ IN OUT EFI_SYSTEM_CONTEXT_X64 *Regs,
+ IN SEV_ES_INSTRUCTION_DATA *InstructionData
+ )
+{
+ UINT64 Status;
+
+ Status = VmgExit (Ghcb, SVM_EXIT_WBINVD, 0, 0);
+ if (Status) {
+ return Status;
+ }
+
+ return 0;
(1) I'd simplify:
return VmgExit (Ghcb, SVM_EXIT_WBINVD, 0, 0);
unless you want to keep the Status variable (maybe for inserting DEBUG
statements more easily, if needed). Even in that case:
Status = VmgExit (Ghcb, SVM_EXIT_WBINVD, 0, 0);
return Status;
With either option adopted:
Acked-by: Laszlo Ersek <ler...@redhat.com>
(The real wart I'm trying to address here is the evaluation of "Status"
in a logical context, as usual.)
Yup, I'm going through all of the patches.
Thanks!
Tom
Thanks,
Laszlo
+}
+
/**
Handle an MSR event.
@@ -1238,6 +1270,10 @@ VmgExitHandleVc (
NaeExit = MsrExit;
break;
+ case SVM_EXIT_WBINVD:
+ NaeExit = WbinvdExit;
+ break;
+
case SVM_EXIT_NPF:
NaeExit = MmioExit;
break;
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