This is a note to let you know that I've just added the patch titled
KVM: Fix iommu map/unmap to handle memory slot moves
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-fix-iommu-map-unmap-to-handle-memory-slot-moves.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e40f193f5bb022e927a57a4f5d5194e4f12ddb74 Mon Sep 17 00:00:00 2001
From: Alex Williamson <alex.williamson@xxxxxxxxxx>
Date: Mon, 10 Dec 2012 10:32:57 -0700
Subject: KVM: Fix iommu map/unmap to handle memory slot moves
From: Alex Williamson <alex.williamson@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Cc: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
virt/kvm/kvm_main.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -790,6 +790,8 @@ int __kvm_set_memory_region(struct 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 *
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 *
return 0;
+out_slots:
+ kfree(slots);
out_free:
kvm_free_physmem_slot(&new, &old);
out:
Patches currently in stable-queue which might be from alex.williamson@xxxxxxxxxx are
queue-3.4/kvm-fix-iommu-map-unmap-to-handle-memory-slot-moves.patch
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