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[5.10/5.11,7/9] KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping

Message ID 20210410151229.4062930-8-pbonzini@redhat.com (mailing list archive)
State New, archived
Headers show
Series Fix missing TLB flushes in TDP MMU | expand

Commit Message

Paolo Bonzini April 10, 2021, 3:12 p.m. UTC
From: Sean Christopherson <seanjc@google.com>

[ Upstream commit 048f49809c526348775425420fb5b8e84fd9a133 ]

Honor the "flush needed" return from kvm_tdp_mmu_zap_gfn_range(), which
does the flush itself if and only if it yields (which it will never do in
this particular scenario), and otherwise expects the caller to do the
flush.  If pages are zapped from the TDP MMU but not the legacy MMU, then
no flush will occur.

Fixes: 29cf0f5007a2 ("kvm: x86/mmu: NX largepage recovery for TDP MMU")
Cc: stable@vger.kernel.org
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210325200119.1359384-3-seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
 arch/x86/kvm/mmu/mmu.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)
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diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index ed861245ecf0..64ac8ae4f7a1 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5985,6 +5985,8 @@  static void kvm_recover_nx_lpages(struct kvm *kvm)
 	struct kvm_mmu_page *sp;
 	unsigned int ratio;
+	bool flush = false;
+	gfn_t gfn_end;
 	ulong to_zap;
 	rcu_idx = srcu_read_lock(&kvm->srcu);
@@ -6006,19 +6008,20 @@  static void kvm_recover_nx_lpages(struct kvm *kvm)
 		if (sp->tdp_mmu_page)
-			kvm_tdp_mmu_zap_gfn_range(kvm, sp->gfn,
-				sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level));
-		else {
+			gfn_end = sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level);
+			flush = kvm_tdp_mmu_zap_gfn_range(kvm, sp->gfn, gfn_end);
+		} else {
 			kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
 		if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
-			kvm_mmu_commit_zap_page(kvm, &invalid_list);
+			kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
+			flush = false;
-	kvm_mmu_commit_zap_page(kvm, &invalid_list);
+	kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
 	srcu_read_unlock(&kvm->srcu, rcu_idx);