From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Sean Christopherson <sean.j.christopherson@intel.com>
Subject: [PATCH v4 07/11] KVM: VMX: Don't invalidate hv_tlb_eptp if the new EPTP matches
Date: Fri, 5 Mar 2021 10:31:19 -0800 [thread overview]
Message-ID: <20210305183123.3978098-8-seanjc@google.com> (raw)
In-Reply-To: <20210305183123.3978098-1-seanjc@google.com>
From: Sean Christopherson <sean.j.christopherson@intel.com>
Don't invalidate the common EPTP, and thus trigger rechecking of EPTPs
across all vCPUs, if the new EPTP matches the old/common EPTP. In all
likelihood this is a meaningless optimization, but there are (uncommon)
scenarios where KVM can reload the same EPTP.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/vmx/vmx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2582df5ae64d..cd0d787b0a85 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3117,7 +3117,8 @@ static void vmx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
if (kvm_x86_ops.tlb_remote_flush) {
spin_lock(&to_kvm_vmx(kvm)->ept_pointer_lock);
to_vmx(vcpu)->ept_pointer = eptp;
- to_kvm_vmx(kvm)->hv_tlb_eptp = INVALID_PAGE;
+ if (eptp != to_kvm_vmx(kvm)->hv_tlb_eptp)
+ to_kvm_vmx(kvm)->hv_tlb_eptp = INVALID_PAGE;
spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock);
}
--
2.30.1.766.gb4fecdf3b7-goog
next prev parent reply other threads:[~2021-03-05 18:35 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 18:31 [PATCH v4 00/11] KVM: VMX: Clean up Hyper-V PV TLB flush Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 01/11] KVM: x86: Get active PCID only when writing a CR3 value Sean Christopherson
2021-03-08 10:05 ` Vitaly Kuznetsov
2021-03-05 18:31 ` [PATCH v4 02/11] KVM: VMX: Track common EPTP for Hyper-V's paravirt TLB flush Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 03/11] KVM: VMX: Stash kvm_vmx in a local variable for Hyper-V " Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 04/11] KVM: VMX: Fold Hyper-V EPTP checking into it's only caller Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 05/11] KVM: VMX: Do Hyper-V TLB flush iff vCPU's EPTP hasn't been flushed Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 06/11] KVM: VMX: Invalidate hv_tlb_eptp to denote an EPTP mismatch Sean Christopherson
2021-03-05 18:31 ` Sean Christopherson [this message]
2021-03-05 18:31 ` [PATCH v4 08/11] KVM: VMX: Explicitly check for hv_remote_flush_tlb when loading pgd Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 09/11] KVM: VMX: Define Hyper-V paravirt TLB flush fields iff Hyper-V is enabled Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 10/11] KVM: VMX: Skip additional Hyper-V TLB EPTP flushes if one fails Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 11/11] KVM: VMX: Track root HPA instead of EPTP for paravirt Hyper-V TLB flush Sean Christopherson
2021-03-05 18:33 ` [PATCH v4 00/11] KVM: VMX: Clean up Hyper-V PV " Sean Christopherson
2021-03-08 11:50 ` Paolo Bonzini
2021-03-09 1:18 ` Sean Christopherson
2021-03-09 8:35 ` Paolo Bonzini
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