On Fri, Aug 29, 2025 at 02:47:37PM +0800, Xiaoyao Li wrote: >On 8/21/2025 9:30 PM, Chao Gao wrote: >> From: Yang Weijiang <weijiang.yang@xxxxxxxxx> >> >> Update CPUID.(EAX=0DH,ECX=1).EBX to reflect current required xstate size >> due to XSS MSR modification. >> CPUID(EAX=0DH,ECX=1).EBX reports the required storage size of all enabled >> xstate features in (XCR0 | IA32_XSS). The CPUID value can be used by guest >> before allocate sufficient xsave buffer. >> >> Note, KVM does not yet support any XSS based features, i.e. supported_xss >> is guaranteed to be zero at this time. >> >> Opportunistically return KVM_MSR_RET_UNSUPPORTED if guest CPUID doesn't >> enumerate it. Since KVM_MSR_RET_UNSUPPORTED takes care of host_initiated >> cases, drop the host_initiated check. > >It looks most of this patch is introducing > > vcpu->arch.guest_supported_xss > >and use it to guard the wrmsr of MSR_IA32_XSS instead of KVM global >kvm_caps.supported_xss. > >So it's better to split it into two patches? Yes. it makes sense. will do.
