Re: [PATCH v3 2/2] KVM: SVM: Add support for Virtual SPEC_CTRL

[Sean Christopherson]

On Wed, Jan 20, 2021, Babu Moger wrote:
> 
> On 1/19/21 5:45 PM, Sean Christopherson wrote:

> > Potentially harebrained alternative...
> > 
> > From an architectural SVM perspective, what are the rules for VMCB fields that
> > don't exist (on the current hardware)?  E.g. are they reserved MBZ?  If not,
> > does the SVM architecture guarantee that reserved fields will not be modified?
> > I couldn't (quickly) find anything in the APM that explicitly states what
> > happens with defined-but-not-existent fields.
> 
> I checked with our hardware design team about this. They dont want
> software to make any assumptions about these fields.

Drat, I should have begged for forgiveness instead of asking for permission :-D