From: Paolo Bonzini <pbonzini@redhat.com>
Date: Mon, 25 Jun 2018 12:04:37 +0000 (+0200)
Subject: KVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR
X-Git-Tag: v4.1.12-124.31.3~612
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=2c9e90e967d5225c3762600bfdf82f8e1202d0c9;p=users%2Fjedix%2Flinux-maple.git

KVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR

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>

Orabug: 28220625
CVE: CVE-2018-3646

(cherry picked from commit cd28325249a1ca0d771557ce823e0308ad629f98)

Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Conflicts:
	arch/x86/kvm/x86.c
Contextual: different content
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 28265fb63571..039ea0392285 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -970,6 +970,7 @@ static const u32 emulated_msrs[] = {
  * can be used by a hypervisor to validate requested CPU features.
  */
 static u32 msr_based_features[] = {
+	MSR_IA32_ARCH_CAPABILITIES,
 };
 
 static unsigned int num_msr_based_features;
@@ -977,6 +978,9 @@ static unsigned int num_msr_based_features;
 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;