Messages in this thread | | | Subject | Re: [PATCH 1/2] KVM: x86: Add emulation support for #GP triggered by VM instructions | From | Wei Huang <> | Date | Tue, 12 Jan 2021 23:03:58 -0600 |
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On 1/12/21 11:59 AM, Sean Christopherson wrote: > On Tue, Jan 12, 2021, Sean Christopherson wrote: >> On Tue, Jan 12, 2021, Wei Huang wrote: >>> From: Bandan Das <bsd@redhat.com> >>> >>> 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?
This behavior was dated back to fairly old CPUs. It is fair to assume that _most_ CPUs without this CPUID bit can demonstrate such behavior.
> > 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?
Sure, will do in the next version.
>
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