From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Paolo Bonzini <pbonzini@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: Re: [PATCH v3 05/11] KVM: VMX: Do Hyper-V TLB flush iff vCPU's EPTP hasn't been flushed
Date: Thu, 12 Nov 2020 11:47:41 +0100 [thread overview]
Message-ID: <878sb6zwaa.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20201027212346.23409-6-sean.j.christopherson@intel.com>
Sean Christopherson <sean.j.christopherson@intel.com> writes:
> Combine the for-loops for Hyper-V TLB EPTP checking and flushing, and in
> doing so skip flushes for vCPUs whose EPTP matches the target EPTP.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
> arch/x86/kvm/vmx/vmx.c | 23 ++++++++---------------
> 1 file changed, 8 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index f5e9e2f61e10..17b228c4ba19 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -505,33 +505,26 @@ static int hv_remote_flush_tlb_with_range(struct kvm *kvm,
>
> spin_lock(&kvm_vmx->ept_pointer_lock);
>
> - if (kvm_vmx->ept_pointers_match == EPT_POINTERS_CHECK) {
> + if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) {
> kvm_vmx->ept_pointers_match = EPT_POINTERS_MATCH;
> kvm_vmx->hv_tlb_eptp = INVALID_PAGE;
>
> kvm_for_each_vcpu(i, vcpu, kvm) {
> tmp_eptp = to_vmx(vcpu)->ept_pointer;
> - if (!VALID_PAGE(tmp_eptp))
> + if (!VALID_PAGE(tmp_eptp) ||
> + tmp_eptp == kvm_vmx->hv_tlb_eptp)
> continue;
>
> - if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp)) {
> + if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp))
> kvm_vmx->hv_tlb_eptp = tmp_eptp;
> - } else if (kvm_vmx->hv_tlb_eptp != tmp_eptp) {
> - kvm_vmx->hv_tlb_eptp = INVALID_PAGE;
> + else
> kvm_vmx->ept_pointers_match
> = EPT_POINTERS_MISMATCH;
> - break;
> - }
> - }
> - }
>
> - if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) {
> - kvm_for_each_vcpu(i, vcpu, kvm) {
> - /* If ept_pointer is invalid pointer, bypass flush request. */
> - if (VALID_PAGE(to_vmx(vcpu)->ept_pointer))
> - ret |= hv_remote_flush_eptp(to_vmx(vcpu)->ept_pointer,
> - range);
> + ret |= hv_remote_flush_eptp(tmp_eptp, range);
> }
> + if (kvm_vmx->ept_pointers_match == EPT_POINTERS_MISMATCH)
> + kvm_vmx->hv_tlb_eptp = INVALID_PAGE;
> } else if (VALID_PAGE(kvm_vmx->hv_tlb_eptp)) {
> ret = hv_remote_flush_eptp(kvm_vmx->hv_tlb_eptp, range);
> }
It seems this patch makes EPT_POINTERS_MISMATCH an alias for
EPT_POINTERS_CHECK but this all is gone in the next patch, so
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
--
Vitaly
next prev parent reply other threads:[~2020-11-12 10:47 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-27 21:23 [PATCH v3 00/11] KVM: VMX: Clean up Hyper-V PV TLB flush Sean Christopherson
2020-10-27 21:23 ` [PATCH v3 01/11] KVM: x86: Get active PCID only when writing a CR3 value Sean Christopherson
2020-11-12 10:11 ` Vitaly Kuznetsov
2021-01-27 17:30 ` Paolo Bonzini
2020-10-27 21:23 ` [PATCH v3 02/11] KVM: VMX: Track common EPTP for Hyper-V's paravirt TLB flush Sean Christopherson
2020-11-12 10:27 ` Vitaly Kuznetsov
2020-10-27 21:23 ` [PATCH v3 03/11] KVM: VMX: Stash kvm_vmx in a local variable for Hyper-V " Sean Christopherson
2020-10-27 21:23 ` [PATCH v3 04/11] KVM: VMX: Fold Hyper-V EPTP checking into it's only caller Sean Christopherson
2020-11-12 10:41 ` Vitaly Kuznetsov
2020-10-27 21:23 ` [PATCH v3 05/11] KVM: VMX: Do Hyper-V TLB flush iff vCPU's EPTP hasn't been flushed Sean Christopherson
2020-11-12 10:47 ` Vitaly Kuznetsov [this message]
2020-10-27 21:23 ` [PATCH v3 06/11] KVM: VMX: Invalidate hv_tlb_eptp to denote an EPTP mismatch Sean Christopherson
2020-11-12 10:50 ` Vitaly Kuznetsov
2020-10-27 21:23 ` [PATCH v3 07/11] KVM: VMX: Don't invalidate hv_tlb_eptp if the new EPTP matches Sean Christopherson
2020-10-27 21:23 ` [PATCH v3 08/11] KVM: VMX: Explicitly check for hv_remote_flush_tlb when loading pgd Sean Christopherson
2020-10-27 21:23 ` [PATCH v3 09/11] KVM: VMX: Define Hyper-V paravirt TLB flush fields iff Hyper-V is enabled Sean Christopherson
2020-11-12 10:52 ` Vitaly Kuznetsov
2020-10-27 21:23 ` [PATCH v3 10/11] KVM: VMX: Skip additional Hyper-V TLB EPTP flushes if one fails Sean Christopherson
2020-11-12 10:59 ` Vitaly Kuznetsov
2020-10-27 21:23 ` [PATCH v3 11/11] KVM: VMX: Track root HPA instead of EPTP for paravirt Hyper-V TLB flush Sean Christopherson
2020-11-12 11:02 ` Vitaly Kuznetsov
2021-01-27 18:10 ` [PATCH v3 00/11] KVM: VMX: Clean up Hyper-V PV " Paolo Bonzini
2021-03-02 18:56 ` Sean Christopherson
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