From e40f193f5bb022e927a57a4f5d5194e4f12ddb74 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 10 Dec 2012 10:32:57 -0700 Subject: [PATCH] KVM: Fix iommu map/unmap to handle memory slot moves 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 Signed-off-by: Alex Williamson Signed-off-by: Marcelo Tosatti --- virt/kvm/kvm_main.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index e4d3581..9a56ca2 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -822,6 +822,8 @@ 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. * @@ -837,20 +839,19 @@ 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.dirty_bitmap = NULL; @@ -869,6 +870,8 @@ int __kvm_set_memory_region(struct kvm *kvm, return 0; +out_slots: + kfree(slots); out_free: kvm_free_physmem_slot(&new, &old); out: -- 2.7.4