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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 v3 10/11] KVM: VMX: Skip additional Hyper-V TLB EPTP flushes if one fails
Date: Tue, 27 Oct 2020 14:23:45 -0700	[thread overview]
Message-ID: <20201027212346.23409-11-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20201027212346.23409-1-sean.j.christopherson@intel.com>

Skip additional EPTP flushes if one fails when processing EPTPs for
Hyper-V's paravirt TLB flushing.  If _any_ flush fails, KVM falls back
to a full global flush, i.e. additional flushes are unnecessary (and
will likely fail anyways).

Continue processing the loop unless a mismatch was already detected,
e.g. to handle the case where the first flush fails and there is a
yet-to-be-detected mismatch.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5b7c5b2fd2c7..40a67dd45c8c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -528,7 +528,15 @@ static int hv_remote_flush_tlb_with_range(struct kvm *kvm,
 			if (++nr_unique_valid_eptps == 1)
 				kvm_vmx->hv_tlb_eptp = tmp_eptp;
 
-			ret |= hv_remote_flush_eptp(tmp_eptp, range);
+			if (!ret)
+				ret = hv_remote_flush_eptp(tmp_eptp, range);
+
+			/*
+			 * Stop processing EPTPs if a failure occurred and
+			 * there is already a detected EPTP mismatch.
+			 */
+			if (ret && nr_unique_valid_eptps > 1)
+				break;
 		}
 
 		/*
-- 
2.28.0


  parent reply	other threads:[~2020-10-27 21:34 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
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 ` Sean Christopherson [this message]
2020-11-12 10:59   ` [PATCH v3 10/11] KVM: VMX: Skip additional Hyper-V TLB EPTP flushes if one fails 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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