linux-kernel - [PATCH 2/3] KVM: eVMCS: check if nesting is enabled

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Date:   Fri, 17 Apr 2020 12:44:12 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>
Subject: [PATCH 2/3] KVM: eVMCS: check if nesting is enabled

In the next patch nested_get_evmcs_version will be always set in kvm_x86_ops for
VMX, even if nesting is disabled.  Therefore, check whether VMX (aka nesting)
is available in the function, the caller will not do the check anymore.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/vmx/evmcs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index 73f3e07c1852..48dc77de9337 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -4,6 +4,7 @@
 #include <linux/smp.h>
 
 #include "../hyperv.h"
+#include "../cpuid.h"
 #include "evmcs.h"
 #include "vmcs.h"
 #include "vmx.h"
@@ -333,7 +334,8 @@ uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu)
         * maximum supported version. KVM supports versions from 1 to
         * KVM_EVMCS_VERSION.
         */
-       if (vmx->nested.enlightened_vmcs_enabled)
+       if (kvm_cpu_cap_get(X86_FEATURE_VMX) &&
+	   vmx->nested.enlightened_vmcs_enabled)
                return (KVM_EVMCS_VERSION << 8) | 1;
 
        return 0;
-- 
2.18.2