Re: [PATCH v4 18/20] KVM:x86: Enable guest CET supervisor xstate bit support

[Chao Gao]

On Thu, Jul 20, 2023 at 11:03:50PM -0400, Yang Weijiang wrote:
> 
> u64 __read_mostly host_efer;
> EXPORT_SYMBOL_GPL(host_efer);
>@@ -9638,6 +9639,7 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
> 	if (boot_cpu_has(X86_FEATURE_XSAVES)) {
> 		rdmsrl(MSR_IA32_XSS, host_xss);
> 		kvm_caps.supported_xss = host_xss & KVM_SUPPORTED_XSS;

>+		kvm_caps.supported_xss |= XFEATURE_MASK_CET_KERNEL;

Hardware may not support S_CET state management via XSAVES. we need to
consult CPUID.0xD.1[bit12].