[PATCH v3 1/2] KVM: VMX: enable X86_FEATURE_WAITPKG in KVM capabilities

[Maxim Levitsky <mlevitsk@redhat.com>]

Even though we might not allow the guest to use WAITPKG's new instructions,
we should tell KVM that the feature is supported by the host CPU.

Note that vmx_waitpkg_supported checks that WAITPKG _can_ be set in the
secondary execution controls as specified by VMX capability MSR,
rather that indicate that we actually enable it for a guest.

Fixes: e69e72faa3a07 (KVM: x86: Add support for user wait instructions)

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
---
 arch/x86/kvm/vmx/vmx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 55712dd86bafa..fca493d4517c5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7298,6 +7298,9 @@ static __init void vmx_set_cpu_caps(void)
 	/* CPUID 0x80000001 */
 	if (!cpu_has_vmx_rdtscp())
 		kvm_cpu_cap_clear(X86_FEATURE_RDTSCP);
+
+	if (vmx_waitpkg_supported())
+		kvm_cpu_cap_check_and_set(X86_FEATURE_WAITPKG);
 }
 
 static void vmx_request_immediate_exit(struct kvm_vcpu *vcpu)
-- 
2.26.2