On Tue, Jan 12, 2021 at 9:59 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > On Tue, Jan 12, 2021, Sean Christopherson wrote: > > On Tue, Jan 12, 2021, Wei Huang wrote: > > > From: Bandan Das <bsd@xxxxxxxxxx> > > > > > > While running VM related instructions (VMRUN/VMSAVE/VMLOAD), some AMD > > > CPUs check EAX against reserved memory regions (e.g. SMM memory on host) > > > before checking VMCB's instruction intercept. > > > > It would be very helpful to list exactly which CPUs are/aren't affected, even if > > that just means stating something like "all CPUs before XYZ". Given patch 2/2, > > I assume it's all CPUs without the new CPUID flag? > > Ah, despite calling this an 'errata', the bad behavior is explicitly documented > in the APM, i.e. it's an architecture bug, not a silicon bug. > > Can you reword the changelog to make it clear that the premature #GP is the > correct architectural behavior for CPUs without the new CPUID flag? Andrew Cooper points out that there may be a nicer workaround. Make sure that the SMRAM and HT region (FFFD00000000 - FFFFFFFFFFFF) are marked as reserved in the guest, too. --Andy
