From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 15 Aug 2019 07:43:32 +0000 (+0200)
Subject: Revert "KVM: x86/mmu: Zap only the relevant pages when removing a memslot"
X-Git-Tag: v5.2.11~52
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=2ad350fb4c924f611d174e2b0da4edba8a6e430a;p=users%2Fdwmw2%2Flinux.git

Revert "KVM: x86/mmu: Zap only the relevant pages when removing a memslot"

commit d012a06ab1d23178fc6856d8d2161fbcc4dd8ebd upstream.

This reverts commit 4e103134b862314dc2f2f18f2fb0ab972adc3f5f.
Alex Williamson reported regressions with device assignment with
this patch.  Even though the bug is probably elsewhere and still
latent, this is needed to fix the regression.

Fixes: 4e103134b862 ("KVM: x86/mmu: Zap only the relevant pages when removing a memslot", 2019-02-05)
Reported-by: Alex Willamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8d95c81b2c821..01f04db1fa61c 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5649,38 +5649,7 @@ static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm,
 			struct kvm_memory_slot *slot,
 			struct kvm_page_track_notifier_node *node)
 {
-	struct kvm_mmu_page *sp;
-	LIST_HEAD(invalid_list);
-	unsigned long i;
-	bool flush;
-	gfn_t gfn;
-
-	spin_lock(&kvm->mmu_lock);
-
-	if (list_empty(&kvm->arch.active_mmu_pages))
-		goto out_unlock;
-
-	flush = slot_handle_all_level(kvm, slot, kvm_zap_rmapp, false);
-
-	for (i = 0; i < slot->npages; i++) {
-		gfn = slot->base_gfn + i;
-
-		for_each_valid_sp(kvm, sp, gfn) {
-			if (sp->gfn != gfn)
-				continue;
-
-			kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
-		}
-		if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
-			kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
-			flush = false;
-			cond_resched_lock(&kvm->mmu_lock);
-		}
-	}
-	kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
-
-out_unlock:
-	spin_unlock(&kvm->mmu_lock);
+	kvm_mmu_zap_all(kvm);
 }
 
 void kvm_mmu_init_vm(struct kvm *kvm)