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authorAlex Williamson <alex.williamson@redhat.com>2012-12-10 10:32:57 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-12-04 10:50:34 -0800
commit5833570f8e15cd7a40dd6c14ec73cb53736048cf (patch)
tree3fd955b0612b7f75f60e71994fb3d5a79e8b79a5
parent9af88f0e8b1ce5f10786654c3f00adde1c67a2e5 (diff)
downloadlwn-5833570f8e15cd7a40dd6c14ec73cb53736048cf.tar.gz
lwn-5833570f8e15cd7a40dd6c14ec73cb53736048cf.zip
KVM: Fix iommu map/unmap to handle memory slot moves
commit e40f193f5bb022e927a57a4f5d5194e4f12ddb74 upstream. The iommu integration into memory slots expects memory slots to be added or removed and doesn't handle the move case. We can unmap slots from the iommu after we mark them invalid and map them before installing the final memslot array. Also re-order the kmemdup vs map so we don't leave iommu mappings if we get ENOMEM. Reviewed-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Cc: Luis Henriques <luis.henriques@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--virt/kvm/kvm_main.c19
1 files changed, 11 insertions, 8 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f542d79faad2..91a0a2f8cbc7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -790,6 +790,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
old_memslots = kvm->memslots;
rcu_assign_pointer(kvm->memslots, slots);
synchronize_srcu_expedited(&kvm->srcu);
+ /* slot was deleted or moved, clear iommu mapping */
+ kvm_iommu_unmap_pages(kvm, &old);
/* From this point no new shadow pages pointing to a deleted,
* or moved, memslot will be created.
*
@@ -805,20 +807,19 @@ int __kvm_set_memory_region(struct kvm *kvm,
if (r)
goto out_free;
- /* map/unmap the pages in iommu page table */
- if (npages) {
- r = kvm_iommu_map_pages(kvm, &new);
- if (r)
- goto out_free;
- } else
- kvm_iommu_unmap_pages(kvm, &old);
-
r = -ENOMEM;
slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
GFP_KERNEL);
if (!slots)
goto out_free;
+ /* map new memory slot into the iommu */
+ if (npages) {
+ r = kvm_iommu_map_pages(kvm, &new);
+ if (r)
+ goto out_slots;
+ }
+
/* actual memory is freed via old in kvm_free_physmem_slot below */
if (!npages) {
new.rmap = NULL;
@@ -845,6 +846,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
return 0;
+out_slots:
+ kfree(slots);
out_free:
kvm_free_physmem_slot(&new, &old);
out: