On Wed, Feb 10, 2021 at 03:31:57AM -0500,
"Michael S. Tsirkin" <m...@redhat.com> wrote:
> On Tue, Feb 09, 2021 at 12:02:58PM -0800, Isaku Yamahata wrote:
> > > > + * When the method of _CRS is called to determine MMCONFIG region,
> > > > + * only port io is allowed to access PCI configuration space.
> > > > + * It means qword access isn't allowed.
> > > > + *
> > > > + * Device(DRAC)
> > > > + * {
> > > > + * Name(_HID, EisaId("PNP0C01"))
> > > > + * OperationRegion(DRR0, PCI_Config, 0x0000000000000060, 0x8)
> > > > + * Field(DRR0, DWordAcc, Lock, Preserve)
> > > > + * {
> > > > + * PEBL, 4,
> > > > + * PEBH, 4
> > > > + * }
> > >
> > > why are you trying to fetch it dynamically?
> > > what prevents you from getting MMCONFIG address in QEMU when building
> > > ACPI tables and encode _CRS statically at that time?
> >
> > My motivation is to prepare for TDX where ACPI tables will be part of
> > measurement. I wanted ACPI tables to remain same irrelevant of chipset
> > configuration which guest can change.
>
> I mean we are encoding lots of things like PCI description which is
> guest controllable. Is there reason to think mmconfig specifically will
> change after measurement?
No in fact.
I'll switch to use MMCONFIG address in qemu.
--
Isaku Yamahata <isaku.yamah...@gmail.com>
