From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Mon, 3 Aug 2009 17:57:48 +0000 (-0300)
Subject: KVM: take mmu_lock when updating a deleted slot
X-Git-Tag: v2.6.30.6~54
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4877f4a4c8d80472228e0c843fee5957ae1f94d1;p=thirdparty%2Fkernel%2Fstable.git

KVM: take mmu_lock when updating a deleted slot

(cherry picked from commit b43b1901ad282aeb74161837fb403927102687a1)

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 148982913805d..fe0b1eee0898d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1055,8 +1055,10 @@ 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);