[PATCH v6 06/31] KVM: nSVM: Refactor checking LBRV enablement in vmcb12 into a helper

[Yosry Ahmed <yosry@kernel.org>]

Refactor the vCPU cap and vmcb12 flag checks into a helper. The
unlikely() annotation is dropped, it's unlikely (huh) to make a
difference and the CPU will probably predict it better on its own.

CC: stable@vger.kernel.org
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
---
 arch/x86/kvm/svm/nested.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index fab0d3d5baa27..d11cf4968adbe 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -639,6 +639,12 @@ void nested_vmcb02_compute_g_pat(struct vcpu_svm *svm)
 	svm->nested.vmcb02.ptr->save.g_pat = svm->vmcb01.ptr->save.g_pat;
 }
 
+static bool nested_vmcb12_has_lbrv(struct kvm_vcpu *vcpu)
+{
+	return guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) &&
+		(to_svm(vcpu)->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK);
+}
+
 static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12)
 {
 	bool new_vmcb12 = false;
@@ -703,8 +709,7 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12
 		vmcb_mark_dirty(vmcb02, VMCB_DR);
 	}
 
-	if (unlikely(guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) &&
-		     (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) {
+	if (nested_vmcb12_has_lbrv(vcpu)) {
 		/*
 		 * Reserved bits of DEBUGCTL are ignored.  Be consistent with
 		 * svm_set_msr's definition of reserved bits.
@@ -1232,8 +1237,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 	if (!nested_exit_on_intr(svm))
 		kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
 
-	if (unlikely(guest_cpu_cap_has(vcpu, X86_FEATURE_LBRV) &&
-		     (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) {
+	if (nested_vmcb12_has_lbrv(vcpu)) {
 		svm_copy_lbrs(&vmcb12->save, &vmcb02->save);
 	} else {
 		svm_copy_lbrs(&vmcb01->save, &vmcb02->save);
-- 
2.53.0.414.gf7e9f6c205-goog