[edk2-devel] [PATCH V2 1/1] OvmfPkg/VmgExitLig: HALT on #VE when access to private memory
Min Xu
min.m.xu at intel.com
Fri Oct 28 08:24:01 UTC 2022
From: Min M Xu <min.m.xu at intel.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4125
EPT-violation #VE should be always on shared memory, which means the
shared bit of the GuestPA should be set. But in current #VE Handler
it is not checked. When it occurs, stop TD immediately and log out
the error.
Cc: Erdem Aktas <erdemaktas at google.com>
Cc: Gerd Hoffmann <kraxel at redhat.com>
Cc: James Bottomley <jejb at linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Cc: Tom Lendacky <thomas.lendacky at amd.com>
Signed-off-by: Min Xu <min.m.xu at intel.com>
---
.../Library/VmgExitLib/VmTdExitVeHandler.c | 40 ++++++++++++++-----
1 file changed, 29 insertions(+), 11 deletions(-)
diff --git a/OvmfPkg/Library/VmgExitLib/VmTdExitVeHandler.c b/OvmfPkg/Library/VmgExitLib/VmTdExitVeHandler.c
index b73e877c093b..c89268c5d8e8 100644
--- a/OvmfPkg/Library/VmgExitLib/VmTdExitVeHandler.c
+++ b/OvmfPkg/Library/VmgExitLib/VmTdExitVeHandler.c
@@ -300,23 +300,41 @@ MmioExit (
IN TDCALL_VEINFO_RETURN_DATA *Veinfo
)
{
- UINT64 Status;
- UINT32 MmioSize;
- UINT32 RegSize;
- UINT8 OpCode;
- BOOLEAN SeenRex;
- UINT64 *Reg;
- UINT8 *Rip;
- UINT64 Val;
- UINT32 OpSize;
- MODRM ModRm;
- REX Rex;
+ UINT64 Status;
+ UINT32 MmioSize;
+ UINT32 RegSize;
+ UINT8 OpCode;
+ BOOLEAN SeenRex;
+ UINT64 *Reg;
+ UINT8 *Rip;
+ UINT64 Val;
+ UINT32 OpSize;
+ MODRM ModRm;
+ REX Rex;
+ TD_RETURN_DATA TdReturnData;
+ UINT8 Gpaw;
+ UINT64 TdSharedPageMask;
Rip = (UINT8 *)Regs->Rip;
Val = 0;
Rex.Val = 0;
SeenRex = FALSE;
+ Status = TdCall (TDCALL_TDINFO, 0, 0, 0, &TdReturnData);
+ if (Status == TDX_EXIT_REASON_SUCCESS) {
+ Gpaw = (UINT8)(TdReturnData.TdInfo.Gpaw & 0x3f);
+ TdSharedPageMask = 1ULL << (Gpaw - 1);
+ } else {
+ DEBUG ((DEBUG_ERROR, "TDCALL failed with status=%llx\n", Status));
+ return Status;
+ }
+
+ if ((Veinfo->GuestPA & TdSharedPageMask) == 0) {
+ DEBUG ((DEBUG_ERROR, "EPT-violation #VE on private memory is not allowed!"));
+ TdVmCall (TDVMCALL_HALT, 0, 0, 0, 0, 0);
+ CpuDeadLoop ();
+ }
+
//
// Default to 32bit transfer
//
--
2.29.2.windows.2
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