linux-kernel - [PATCH 1/2] KVM: VMX: Don't advertise EPT switching if EPT itself is not exposed

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Date:   Sat, 14 Oct 2017 19:31:09 -0700
From:   Wanpeng Li <kernellwp@...il.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Wanpeng Li <wanpeng.li@...mail.com>
Subject: [PATCH 1/2] KVM: VMX: Don't advertise EPT switching if EPT itself is not exposed

From: Wanpeng Li <wanpeng.li@...mail.com>

EPT switching is advertised unconditionally since it is emulated, however, it can 
be treated as an extended feature for EPT, it should be not advertised if EPT itself
is not exposed. This patch fixes it.

Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Radim Krčmář <rkrcmar@...hat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@...mail.com>
---
 arch/x86/kvm/vmx.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c460b0b..3644540 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2842,8 +2842,9 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx)
 		 * Advertise EPTP switching unconditionally
 		 * since we emulate it
 		 */
-		vmx->nested.nested_vmx_vmfunc_controls =
-			VMX_VMFUNC_EPTP_SWITCHING;
+		if (enable_ept)
+			vmx->nested.nested_vmx_vmfunc_controls =
+				VMX_VMFUNC_EPTP_SWITCHING;
 	}
 
 	/*
-- 
2.7.4