Be good citizens by clearing both CPUID.(EAX=0DH,ECX=0):EAX.XTILECFG[bit-17] and CPUID.(EAX=0DH,ECX=0):EAX.XTILEDATA[bit-18] if they are both not set. That way userspace or a guest doesn't fail if it attempts to set XCR0 with the user xfeature bits, i.e. EDX:EAX of CPUID.(EAX=0DH,ECX=0). Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Aaron Lewis <aaronlewis@xxxxxxxxxx> --- arch/x86/kvm/cpuid.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 0b5bf013fcb8e..2d9910847786a 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -977,6 +977,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) u64 permitted_xcr0 = kvm_caps.supported_xcr0 & xstate_get_guest_group_perm(); u64 permitted_xss = kvm_caps.supported_xss; + if (!(permitted_xcr0 & XFEATURE_MASK_XTILE_CFG) || + !(permitted_xcr0 & XFEATURE_MASK_XTILE_DATA)) + permitted_xcr0 &= ~XFEATURE_MASK_XTILE; + entry->eax &= permitted_xcr0; entry->ebx = xstate_required_size(permitted_xcr0, false); entry->ecx = entry->ebx; -- 2.39.0.314.g84b9a713c41-goog
