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

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>

1 files changed, 1 insertions, 32 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 24843cf49579..218b277bfda3 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5653,38 +5653,7 @@ 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)