>>> On 04.01.17 at 13:39, <andrew.coop...@citrix.com> wrote:
> @@ -380,14 +385,42 @@ void guest_cpuid(const struct vcpu *v, unsigned int
> leaf,
> case 0x80000000 ... 0x80000000 + CPUID_GUEST_NR_EXTD - 1:
> if ( leaf > p->extd.max_leaf )
> return;
> - break;
> + goto legacy;
>
> default:
> return;
> }
>
> + /* Skip dynamic adjustments if we are in the wrong context. */
> + if ( v != curr )
> + return;
> +
> + /*
> + * Second pass:
> + * - Dynamic adjustments
> + */
> + switch ( leaf )
> + {
> + case 0x7:
> + switch ( subleaf )
> + {
> + case 0:
> + /* OSPKE clear in policy. Fast-forward CR4 back in. */
> + if ( (is_pv_vcpu(v)
> + ? v->arch.pv_vcpu.ctrlreg[4]
> + : v->arch.hvm_vcpu.guest_cr[4]) & X86_CR4_PKE )
> + res->c |= cpufeat_mask(X86_FEATURE_OSPKE);
What's wrong with doing this adjustment when v != curr? By
the time the caller looks at the result, the state of guest
software controlled bits can't be relied upon anyway. Which
then raises the question whether a second switch() statement
for the a second pass is all that useful in the first place (I
realize this may depend on future plans of yours).
Jan
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