linux-kernel - [PATCH 2/2] KVM: nVMX: Skip IPBP when switching between vmcs01 and vmcs02, redux

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Date:   Wed,  6 May 2020 16:58:50 -0700
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] KVM: nVMX: Skip IPBP when switching between vmcs01 and vmcs02, redux

Skip the Indirect Branch Prediction Barrier that is triggered on a VMCS
switch when temporarily loading vmcs02 to synchronize it to vmcs12, i.e.
give copy_vmcs02_to_vmcs12_rare() the same treatment as
vmx_switch_vmcs().

Make vmx_vcpu_load() static now that it's only referenced within vmx.c.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/kvm/vmx/nested.c | 4 ++--
 arch/x86/kvm/vmx/vmx.c    | 2 +-
 arch/x86/kvm/vmx/vmx.h    | 1 -
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 7d1e19149ef46..4f770eed66cc9 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3915,12 +3915,12 @@ static void copy_vmcs02_to_vmcs12_rare(struct kvm_vcpu *vcpu,
 
 	cpu = get_cpu();
 	vmx->loaded_vmcs = &vmx->nested.vmcs02;
-	vmx_vcpu_load(&vmx->vcpu, cpu);
+	vmx_vcpu_load_vmcs(vcpu, cpu, &vmx->vmcs01);
 
 	sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
 
 	vmx->loaded_vmcs = &vmx->vmcs01;
-	vmx_vcpu_load(&vmx->vcpu, cpu);
+	vmx_vcpu_load_vmcs(vcpu, cpu, &vmx->nested.vmcs02);
 	put_cpu();
 }
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ddbd8fae24927..bc5e5cf1d4cc8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1383,7 +1383,7 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu,
  * Switches to specified vcpu, until a matching vcpu_put(), but assumes
  * vcpu mutex is already taken.
  */
-void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 4a6f382b05b49..298ddef79d009 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -322,7 +322,6 @@ struct kvm_vmx {
 bool nested_vmx_allowed(struct kvm_vcpu *vcpu);
 void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu,
 			struct loaded_vmcs *buddy);
-void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
 int allocate_vpid(void);
 void free_vpid(int vpid);
 void vmx_set_constant_host_state(struct vcpu_vmx *vmx);
-- 
2.26.0