linux-kernel - [PATCH v2 05/10] KVM: VMX: Invalidate hv_tlb

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Message-Id: <20201020215613.8972-6-sean.j.christopherson@intel.com>
Date:   Tue, 20 Oct 2020 14:56:08 -0700
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2 05/10] KVM: VMX: Invalidate hv_tlb_eptp to denote an EPTP mismatch

Drop the dedicated 'ept_pointers_match' field in favor of stuffing
'hv_tlb_eptp' with INVALID_PAGE to mark it as invalid, i.e. to denote
that there is at least one EPTP mismatch.  Use a local variable to
track whether or not a mismatch is detected so that hv_tlb_eptp can be
used to skip redundant flushes.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/kvm/vmx/vmx.c | 16 ++++++++--------
 arch/x86/kvm/vmx/vmx.h |  7 -------
 2 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 52cb9eec1db3..4dfde8b64750 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -498,13 +498,13 @@ static int hv_remote_flush_tlb_with_range(struct kvm *kvm,
 	struct kvm_vmx *kvm_vmx = to_kvm_vmx(kvm);
 	struct kvm_vcpu *vcpu;
 	int ret = 0, i;
+	bool mismatch;
 	u64 tmp_eptp;
 
 	spin_lock(&kvm_vmx->ept_pointer_lock);
 
-	if (kvm_vmx->ept_pointers_match != EPT_POINTERS_MATCH) {
-		kvm_vmx->ept_pointers_match = EPT_POINTERS_MATCH;
-		kvm_vmx->hv_tlb_eptp = INVALID_PAGE;
+	if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp)) {
+		mismatch = false;
 
 		kvm_for_each_vcpu(i, vcpu, kvm) {
 			tmp_eptp = to_vmx(vcpu)->ept_pointer;
@@ -515,12 +515,13 @@ static int hv_remote_flush_tlb_with_range(struct kvm *kvm,
 			if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp))
 				kvm_vmx->hv_tlb_eptp = tmp_eptp;
 			else
-				kvm_vmx->ept_pointers_match
-					= EPT_POINTERS_MISMATCH;
+				mismatch = true;
 
 			ret |= hv_remote_flush_eptp(tmp_eptp, range);
 		}
-	} else if (VALID_PAGE(kvm_vmx->hv_tlb_eptp)) {
+		if (mismatch)
+			kvm_vmx->hv_tlb_eptp = INVALID_PAGE;
+	} else {
 		ret = hv_remote_flush_eptp(kvm_vmx->hv_tlb_eptp, range);
 	}
 
@@ -3042,8 +3043,7 @@ 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)->ept_pointers_match
-				= EPT_POINTERS_CHECK;
+			to_kvm_vmx(kvm)->hv_tlb_eptp = INVALID_PAGE;
 			spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock);
 		}
 
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 3d557a065c01..e8d7d07b2020 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -288,12 +288,6 @@ struct vcpu_vmx {
 	} shadow_msr_intercept;
 };
 
-enum ept_pointers_status {
-	EPT_POINTERS_CHECK = 0,
-	EPT_POINTERS_MATCH = 1,
-	EPT_POINTERS_MISMATCH = 2
-};
-
 struct kvm_vmx {
 	struct kvm kvm;
 
@@ -302,7 +296,6 @@ struct kvm_vmx {
 	gpa_t ept_identity_map_addr;
 
 	hpa_t hv_tlb_eptp;
-	enum ept_pointers_status ept_pointers_match;
 	spinlock_t ept_pointer_lock;
 };
 
-- 
2.28.0