From: Paolo Bonzini <pbonzini@redhat.com>
Date: Mon, 25 Jun 2018 14:04:37 +0200
Subject: KVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR
Git-commit: cd28325249a1ca0d771557ce823e0308ad629f98
Patch-mainline: v4.18-rc6
References: bsc#1106240

This lets userspace read the MSR_IA32_ARCH_CAPABILITIES and check that all
requested features are available on the host.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/kvm/x86.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1049,6 +1049,7 @@ static unsigned num_emulated_msrs;
  */
 static u32 msr_based_features[] = {
 	MSR_F10H_DECFG,
+	MSR_IA32_ARCH_CAPABILITIES,
 };
 
 static unsigned int num_msr_based_features;
@@ -1056,6 +1057,9 @@ static unsigned int num_msr_based_featur
 static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
 {
 	switch (msr->index) {
+	case MSR_IA32_ARCH_CAPABILITIES:
+		rdmsrl_safe(msr->index, &msr->data);
+		break;
 	default:
 		if (kvm_x86_ops->get_msr_feature(msr))
 			return 1;