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FAILED: patch "[PATCH] KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX" failed to apply to 5.10-stable tree

PATCH [email protected] 1 participant 1 message Apr 10, 2021

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The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 048f49809c526348775425420fb5b8e84fd9a133 Mon Sep 17 00:00:00 2001
From: Sean Christopherson <[email protected]>
Date: Thu, 25 Mar 2021 13:01:18 -0700
Subject: [PATCH] KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX
zapping

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 [email protected]
Cc Ben Gardon <[email protected]>
Signed-off-by Sean Christopherson <[email protected]>

Message-Id: <[email protected]>

Reviewed-by Ben Gardon <[email protected]>
Signed-off-by Paolo Bonzini <[email protected]>
arch/x86/kvm/mmu/mmu.c +7 -4
index d75524bc8423..2705f9fa22b9 100644
@@ -5884,6 +5884,8 @@ static void kvm_recover_nx_lpages(struct kvm *kvm)
 	struct kvm_mmu_page *sp;
 	unsigned int ratio;
 	LIST_HEAD(invalid_list);
+	bool flush = false;
+	gfn_t gfn_end;
 	ulong to_zap;
 
 	rcu_idx = srcu_read_lock(&kvm->srcu);

@@ -5905,19 +5907,20 @@ static void kvm_recover_nx_lpages(struct kvm *kvm)
 				      lpage_disallowed_link);
 		WARN_ON_ONCE(!sp->lpage_disallowed);
 		if (is_tdp_mmu_page(sp)) {
-			kvm_tdp_mmu_zap_gfn_range(kvm, sp->gfn,
-				sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level));
+			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);
 			WARN_ON_ONCE(sp->lpage_disallowed);
 		}
 
 		if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) {
-			kvm_mmu_commit_zap_page(kvm, &invalid_list);
+			kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
 			cond_resched_rwlock_write(&kvm->mmu_lock);
+			flush = false;
 		}
 	}
-	kvm_mmu_commit_zap_page(kvm, &invalid_list);
+	kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
 
 	write_unlock(&kvm->mmu_lock);
 	srcu_read_unlock(&kvm->srcu, rcu_idx);