On 12 Dec 2019, at 19:57, Jim Mattson jmattson@google.com wrote:
On Thu, Dec 12, 2019 at 9:53 AM Liran Alon liran.alon@oracle.com wrote:
Why should CPU VMX features be treated differently than standard CPUID deduced features?
Do we have the right Intel people on the recipient list to answer this question? Presumably, Intel felt that this information should be available in supervisor mode only.
Sean?
Good question. Probably because it just makes sense that Ring3 will never need to use this info as all VMX instructions are privileged. i.e. Can only be executed in Ring0.
De-facto in KVM we have discovered this assumption to be problematic BTW, as KVM created an interface to query VMX MSRs values to properly define the requested vCPU model. :P (See kvm_get_msr_feature())