From 9457a18847e7b62ac1da6f422e3da1bba4aa2304 Mon Sep 17 00:00:00 2001
From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Tue, 21 Jul 2009 20:33:52 -0300
Subject: [PATCH 1/2] KVM: take mmu_lock when updating a deleted slot

kvm_handle_hva relies on mmu_lock protection to safely access
the memslot structures.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
(cherry picked from commit cbb776efc4c8aeeb0a584784d829cbb41983802c)
Bugzilla: 513098
Message-ID: <20090721233352.GB10796@amt.cnet>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
RH-Upstream-status: backport-from-upstream
Acked-by: Izik Eidus <ieidus@redhat.com>
Acked-by: Glauber Costa <glommer@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Juan Quintela <quintela@redhat.com>
---
 virt/kvm/kvm_main.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9b3b379..80fe706 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1206,8 +1206,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
 
 	kvm_free_physmem_slot(&old, npages ? &new : NULL);
 	/* Slot deletion case: we have to update the current slot */
+	spin_lock(&kvm->mmu_lock);
 	if (!npages)
 		*memslot = old;
+	spin_unlock(&kvm->mmu_lock);
 #ifdef CONFIG_DMAR
 	/* map the pages in iommu page table */
 	r = kvm_iommu_map_pages(kvm, base_gfn, npages);
-- 
1.6.3.rc4.29.g8146