On Fri, Mar 08, 2019 at 12:32:04PM +0100, Paolo Bonzini wrote: > On 28/02/19 09:44, Yang Weijiang wrote: > >>> if (!vmx_xsaves_supported()) > >>> return 1; > >>> + > >>> /* > >>> - * The only supported bit as of Skylake is bit 8, but > >>> - * it is not supported on KVM. > >>> + * Check bits being set are supported in KVM. > >> I'd drop the comment altogether, it's pretty obvious from the code that > >> were checking which bits are supported. > > you won't see these redundancies in next version ;) > >>> */ > >>> - if (data != 0) > >>> + if (data & ~kvm_supported_xss()) > >>> return 1; > > You should instead check this against CPUID[0xD, 1].EDX:ECX. If CET is > disabled in CPUID, the guest should not be able to set it in MSR_IA32_CSS. > > Paolo Thanks, OK, will change it.
