linux-kernel - [PATCH 7/9] KVM: VMX: unify SECONDARY_VM_EXEC

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Date:	Fri, 21 Aug 2015 12:50:09 +0800
From:	Xiao Guangrong <guangrong.xiao@...ux.intel.com>
To:	pbonzini@...hat.com
Cc:	gleb@...nel.org, mtosatti@...hat.com, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Xiao Guangrong <guangrong.xiao@...ux.intel.com>
Subject: [PATCH 7/9] KVM: VMX: unify SECONDARY_VM_EXEC_CONTROL update

Unify the update in vmx_cpuid_update()

Signed-off-by: Xiao Guangrong <guangrong.xiao@...ux.intel.com>
---
 arch/x86/kvm/vmx.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0d68140..4f238b7 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8663,19 +8663,15 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpuid_entry2 *best;
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
-	u32 exec_control;
+	u32 clear_exe_ctrl = 0;
 
 	vmx->rdtscp_enabled = false;
 	if (vmx_rdtscp_supported()) {
-		exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
 		best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
 		if (best && (best->edx & bit(X86_FEATURE_RDTSCP)))
 			vmx->rdtscp_enabled = true;
-		else {
-			exec_control &= ~SECONDARY_EXEC_RDTSCP;
-			vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
-					exec_control);
-		}
+		else
+			clear_exe_ctrl |= SECONDARY_EXEC_RDTSCP;
 
 		if (nested && !vmx->rdtscp_enabled)
 			vmx->nested.nested_vmx_secondary_ctls_high &=
@@ -8687,14 +8683,19 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 	if (vmx_invpcid_supported() && (!best ||
 	    !(best->ebx & bit(X86_FEATURE_INVPCID)) ||
 	    !guest_cpuid_has_pcid(vcpu))) {
-		exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
-		exec_control &= ~SECONDARY_EXEC_ENABLE_INVPCID;
-		vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
+		clear_exe_ctrl |= SECONDARY_EXEC_ENABLE_INVPCID;
 
 		if (best)
 			best->ebx &= ~bit(X86_FEATURE_INVPCID);
 	}
 
+	if (clear_exe_ctrl) {
+		u32 exec_ctl = vmcs_read32(SECONDARY_VM_EXEC_CONTROL);
+
+		exec_ctl &= ~clear_exe_ctrl;
+		vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_ctl);
+	}
+
 	if (!guest_cpuid_has_pcommit(vcpu) && nested)
 		vmx->nested.nested_vmx_secondary_ctls_high &=
 			~SECONDARY_EXEC_PCOMMIT;
-- 
2.4.3

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