Re: [edk2-devel] [PATCH v2] OvmfPkg/IncompatiblePciDeviceSupportDxe: Ignore OptionRom in Sev guest

["Ard Biesheuvel" <ardb@kernel.org>]

On Mon, 29 Aug 2022 at 11:32, Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> On Fri, Aug 26, 2022 at 11:15:20PM +0800, Lee, Chun-Yi wrote:
> > Reference: https://bugzilla.tianocore.org/show_bug.cgi?id=4031
> >
> > This patch is similar to the c477b2783f patch for Td guest.
> >
> > Host VMM may inject OptionRom which is untrusted in Sev guest. So PCI
> > OptionRom needs to be ignored if it is Sev guest. According to
> > "Table 20. ACPI 2.0 & 3.0 QWORD Address Space Descriptor Usage"
> > PI spec 1.7, type-specific flags can be set to 0 when Address
> > Translation Offset == 6 to skip device option ROM.
> >
> > Without this patch, Sev guest may shows invalid MMIO opcode error
> > as following:
> >
> > Invalid MMIO opcode (F6)
> > ASSERT /home/abuild/rpmbuild/BUILD/edk2-edk2-stable202202/OvmfPkg/Library/VmgExitLib/VmgExitVcHandler.c(1041): ((BOOLEAN)(0==1))
> >
> > The OptionRom must be disabled both on Td and Sev guests, so we direct
> > use CcProbe().
> >
> > v2: Use CcProbe() instead of TdIsEnabled() and MemEncryptSevIsEnabled().
>
> Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
>

Merged as #3298