On 04/27/21 18:21, Lendacky, Thomas wrote: > From: Tom Lendacky <thomas.lenda...@amd.com> > > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3345 > > The MOVZX and MOVSX instructions use the ModRM byte in the instruction, > but the instruction decoding support was not decoding it. This resulted > in invalid decoding and failing of the MMIO operation. Also, when > performing the zero-extend or sign-extend operation, the memory operation > should be using the size, and not the size enumeration value. > > Add the ModRM byte decoding for the MOVZX and MOVSX opcodes and use the > true data size to perform the extend operations. Additionally, add a > DEBUG statement identifying the MMIO address being flagged as encrypted > during the MMIO address validation. > > Fixes: c45f678a1ea2080344e125dc55b14e4b9f98483d > Cc: Laszlo Ersek <ler...@redhat.com> > Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org> > Cc: Jordan Justen <jordan.l.jus...@intel.com> > Cc: Brijesh Singh <brijesh.si...@amd.com> > Cc: Erdem Aktas <erdemak...@google.com> > Cc: James Bottomley <j...@linux.ibm.com> > Cc: Jiewen Yao <jiewen....@intel.com> > Cc: Min Xu <min.m...@intel.com> > Acked-by: Laszlo Ersek <ler...@redhat.com> > Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com> > --- > OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c > b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c > index 24259060fd65..dd117f971134 100644 > --- a/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c > +++ b/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c > @@ -643,6 +643,7 @@ ValidateMmioMemory ( > // > // Any state other than unencrypted is an error, issue a #GP. > // > + DEBUG ((DEBUG_ERROR, "MMIO using encrypted memory: %lx\n", (UINT64) > MemoryAddress));
(1) This line is now too long -- 86 characters. But I'll fix that up on merge, if I find nothing serious in v2. Thanks Laszlo > GpEvent.Uint64 = 0; > GpEvent.Elements.Vector = GP_EXCEPTION; > GpEvent.Elements.Type = GHCB_EVENT_INJECTION_TYPE_EXCEPTION; > @@ -817,6 +818,7 @@ MmioExit ( > // fall through > // > case 0xB7: > + DecodeModRm (Regs, InstructionData); > Bytes = (Bytes != 0) ? Bytes : 2; > > Status = ValidateMmioMemory (Ghcb, InstructionData->Ext.RmData, Bytes); > @@ -835,7 +837,7 @@ MmioExit ( > } > > Register = GetRegisterPointer (Regs, InstructionData->Ext.ModRm.Reg); > - SetMem (Register, InstructionData->DataSize, 0); > + SetMem (Register, (UINTN) (1 << InstructionData->DataSize), 0); > CopyMem (Register, Ghcb->SharedBuffer, Bytes); > break; > > @@ -848,6 +850,7 @@ MmioExit ( > // fall through > // > case 0xBF: > + DecodeModRm (Regs, InstructionData); > Bytes = (Bytes != 0) ? Bytes : 2; > > Status = ValidateMmioMemory (Ghcb, InstructionData->Ext.RmData, Bytes); > @@ -878,7 +881,7 @@ MmioExit ( > } > > Register = GetRegisterPointer (Regs, InstructionData->Ext.ModRm.Reg); > - SetMem (Register, InstructionData->DataSize, SignByte); > + SetMem (Register, (UINTN) (1 << InstructionData->DataSize), SignByte); > CopyMem (Register, Ghcb->SharedBuffer, Bytes); > break; > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#74567): https://edk2.groups.io/g/devel/message/74567 Mute This Topic: https://groups.io/mt/82407851/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
