On Thu, Aug 27, 2020 at 05:53:16PM +0200, Jan Beulich wrote: > On 20.08.2020 17:08, Roger Pau Monne wrote: > > @@ -181,6 +182,18 @@ int guest_rdmsr(struct vcpu *v, uint32_t msr, uint64_t > > *val) > > /* Not offered to guests. */ > > goto gp_fault; > > > > + case MSR_IA32_FEATURE_CONTROL: > > + if ( !(cp->x86_vendor & X86_VENDOR_INTEL) ) > > + goto gp_fault; > > Can we really do it this way round, rather than raising #GP when > we know the MSR isn't there (AMD / Hygon)? I realized code e.g. > ... > > > + *val = IA32_FEATURE_CONTROL_LOCK; > > + if ( vmce_has_lmce(v) ) > > + *val |= IA32_FEATURE_CONTROL_LMCE_ON; > > + if ( nestedhvm_enabled(d) ) > > + *val |= IA32_FEATURE_CONTROL_ENABLE_VMXON_OUTSIDE_SMX; > > + break; > > + > > + > > case MSR_IA32_PLATFORM_ID: > > if ( !(cp->x86_vendor & X86_VENDOR_INTEL) || > > !(boot_cpu_data.x86_vendor & X86_VENDOR_INTEL) ) > > ... in context right here does it the same way, but I still > wonder whether we wouldn't better switch existing instances, too.
Hm, no idea really. Right now it seems better to check for != Intel rather than AMD | Hygon | Centaur | Shanghai, as that's a MSR specific to Intel. Do those MSRs exist in Centaur / Shanghai? Thanks, Roger.
