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authorSean Christopherson <sean.j.christopherson@intel.com>2020-03-20 14:28:23 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2020-04-21 09:12:54 -0400
commit1196cb970b996be69a2fcd9756117b394f8e7526 (patch)
treeba521037746c95a0d36811044f3ba9718c8e551d /arch
parentc51e1ffee50121a2b2e00208f517a695493ee85d (diff)
KVM: nVMX: Reload APIC access page on nested VM-Exit only if necessary
Defer reloading L1's APIC page by logging the need for a reload and processing it during nested VM-Exit instead of unconditionally reloading the APIC page on nested VM-Exit. This eliminates a TLB flush on the majority of VM-Exits as the APIC page rarely needs to be reloaded. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200320212833.3507-28-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/vmx/nested.c9
-rw-r--r--arch/x86/kvm/vmx/vmx.c10
-rw-r--r--arch/x86/kvm/vmx/vmx.h1
3 files changed, 12 insertions, 8 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index deddf0f0f6e7..a7a526a21292 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4346,11 +4346,10 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
kvm_vcpu_unmap(vcpu, &vmx->nested.pi_desc_map, true);
vmx->nested.pi_desc = NULL;
- /*
- * We are now running in L2, mmu_notifier will force to reload the
- * page's hpa for L2 vmcs. Need to reload it for L1 before entering L1.
- */
- kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu);
+ if (vmx->nested.reload_vmcs01_apic_access_page) {
+ vmx->nested.reload_vmcs01_apic_access_page = false;
+ kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu);
+ }
if ((exit_reason != -1) && (enable_shadow_vmcs || vmx->nested.hv_evmcs))
vmx->nested.need_vmcs12_to_shadow_sync = true;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d958cee52f41..4739b780c74e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6142,10 +6142,14 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
static void vmx_set_apic_access_page_addr(struct kvm_vcpu *vcpu, hpa_t hpa)
{
- if (!is_guest_mode(vcpu)) {
- vmcs_write64(APIC_ACCESS_ADDR, hpa);
- vmx_flush_tlb_current(vcpu);
+ /* Defer reload until vmcs01 is the current VMCS. */
+ if (is_guest_mode(vcpu)) {
+ to_vmx(vcpu)->nested.reload_vmcs01_apic_access_page = true;
+ return;
}
+
+ vmcs_write64(APIC_ACCESS_ADDR, hpa);
+ vmx_flush_tlb_current(vcpu);
}
static void vmx_hwapic_isr_update(struct kvm_vcpu *vcpu, int max_isr)
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 4c7b0713b438..31d7252df163 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -136,6 +136,7 @@ struct nested_vmx {
bool vmcs02_initialized;
bool change_vmcs01_virtual_apic_mode;
+ bool reload_vmcs01_apic_access_page;
/*
* Enlightened VMCS has been enabled. It does not mean that L1 has to