From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.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
Subject: [PATCH v2 06/10] KVM: VMX: Don't invalidate hv_tlb_eptp if the new EPTP matches
Date: Tue, 20 Oct 2020 14:56:09 -0700 [thread overview]
Message-ID: <20201020215613.8972-7-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20201020215613.8972-1-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.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.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 4dfde8b64750..e6569bafacdc 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3043,7 +3043,8 @@ static void vmx_load_mmu_pgd(struct kvm_vcpu *vcpu, unsigned long pgd,
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);
}
--
2.28.0
next prev parent reply other threads:[~2020-10-20 21:57 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-20 21:56 [PATCH v2 00/10] KVM: VMX: Clean up Hyper-V PV TLB flush Sean Christopherson
2020-10-20 21:56 ` [PATCH v2 01/10] KVM: VMX: Track common EPTP for Hyper-V's paravirt " Sean Christopherson
2020-10-21 11:57 ` Vitaly Kuznetsov
2020-10-20 21:56 ` [PATCH v2 02/10] KVM: VMX: Stash kvm_vmx in a local variable for Hyper-V " Sean Christopherson
2020-10-21 12:00 ` Vitaly Kuznetsov
2020-10-20 21:56 ` [PATCH v2 03/10] KVM: VMX: Fold Hyper-V EPTP checking into it's only caller Sean Christopherson
2020-10-21 12:08 ` Vitaly Kuznetsov
2020-10-20 21:56 ` [PATCH v2 04/10] KVM: VMX: Do Hyper-V TLB flush iff vCPU's EPTP hasn't been flushed Sean Christopherson
2020-10-21 12:23 ` Vitaly Kuznetsov
2020-10-20 21:56 ` [PATCH v2 05/10] KVM: VMX: Invalidate hv_tlb_eptp to denote an EPTP mismatch Sean Christopherson
2020-10-21 12:39 ` Vitaly Kuznetsov
2020-10-21 16:38 ` Sean Christopherson
2020-10-22 9:03 ` Vitaly Kuznetsov
2020-10-20 21:56 ` Sean Christopherson [this message]
2020-10-21 13:47 ` [PATCH v2 06/10] KVM: VMX: Don't invalidate hv_tlb_eptp if the new EPTP matches Vitaly Kuznetsov
2020-10-20 21:56 ` [PATCH v2 07/10] KVM: VMX: Explicitly check for hv_remote_flush_tlb when loading pgd Sean Christopherson
[not found] ` <87r1pr4q8z.fsf@vitty.brq.redhat.com>
2020-10-21 17:30 ` Sean Christopherson
2020-10-20 21:56 ` [PATCH v2 08/10] KVM: VMX: Define Hyper-V paravirt TLB flush fields iff Hyper-V is enabled Sean Christopherson
2020-10-21 14:20 ` Vitaly Kuznetsov
2020-10-20 21:56 ` [PATCH v2 09/10] KVM: VMX: Skip additional Hyper-V TLB EPTP flushes if one fails Sean Christopherson
2020-10-21 14:22 ` Vitaly Kuznetsov
2020-10-20 21:56 ` [PATCH v2 10/10] KVM: VMX: Track PGD instead of EPTP for paravirt Hyper-V TLB flush Sean Christopherson
[not found] ` <87imb34p9b.fsf@vitty.brq.redhat.com>
2020-10-21 17:59 ` Sean Christopherson
2020-10-21 9:18 ` [PATCH v2 00/10] KVM: VMX: Clean up Hyper-V PV " Vitaly Kuznetsov
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