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@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?
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.
