Patch "KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kvm-x86-mmu-ensure-tlbs-are-flushed-for-tdp-mmu-duri.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit dda7303a7f509cdc90dea0941d99667faa65e2ae
Author: Sean Christopherson <seanjc@xxxxxxxxxx>
Date:   Sat Apr 10 11:12:27 2021 -0400

    KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping
    
    [ 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@xxxxxxxxxxxxxxx
    Cc: Ben Gardon <bgardon@xxxxxxxxxx>
    Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
    Message-Id: <20210325200119.1359384-3-seanjc@xxxxxxxxxx>
    Reviewed-by: Ben Gardon <bgardon@xxxxxxxxxx>
    Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index dacbd13d32c6..354f9926a183 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5972,6 +5972,8 @@ 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);
@@ -5993,19 +5995,20 @@ static void kvm_recover_nx_lpages(struct kvm *kvm)
 				      lpage_disallowed_link);
 		WARN_ON_ONCE(!sp->lpage_disallowed);
 		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);
 			WARN_ON_ONCE(sp->lpage_disallowed);
 		}
 
 		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);
 			cond_resched_lock(&kvm->mmu_lock);
+			flush = false;
 		}
 	}
-	kvm_mmu_commit_zap_page(kvm, &invalid_list);
+	kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
 
 	spin_unlock(&kvm->mmu_lock);
 	srcu_read_unlock(&kvm->srcu, rcu_idx);