summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAlex Williamson <alex.williamson@redhat.com>2012-11-29 14:07:59 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-17 08:50:42 -0800
commit9d4c74b86237ac64376b92c54cf7b471e7e75f76 (patch)
tree62dbe4253920ec2cc4419e3f6446fb531d6b7a2a
parent91534f7365982fa0c29192e73416dd798397310a (diff)
downloadlinux-3.10-9d4c74b86237ac64376b92c54cf7b471e7e75f76.tar.gz
linux-3.10-9d4c74b86237ac64376b92c54cf7b471e7e75f76.tar.bz2
linux-3.10-9d4c74b86237ac64376b92c54cf7b471e7e75f76.zip
KVM: Fix user memslot overlap check
commit 5419369ed6bd4cf711fdda5e52a5999b940413f5 upstream. Prior to memory slot sorting this loop compared all of the user memory slots for overlap with new entries. With memory slot sorting, we're just checking some number of entries in the array that may or may not be user slots. Instead, walk all the slots with kvm_for_each_memslot, which has the added benefit of terminating early when we hit the first empty slot, and skip comparison to private slots. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--virt/kvm/kvm_main.c13
1 files changed, 5 insertions, 8 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9739b533ca2..71b9036644a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -693,8 +693,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
int r;
gfn_t base_gfn;
unsigned long npages;
- unsigned long i;
- struct kvm_memory_slot *memslot;
+ struct kvm_memory_slot *memslot, *slot;
struct kvm_memory_slot old, new;
struct kvm_memslots *slots, *old_memslots;
@@ -741,13 +740,11 @@ int __kvm_set_memory_region(struct kvm *kvm,
/* Check for overlaps */
r = -EEXIST;
- for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
- struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
-
- if (s == memslot || !s->npages)
+ kvm_for_each_memslot(slot, kvm->memslots) {
+ if (slot->id >= KVM_MEMORY_SLOTS || slot == memslot)
continue;
- if (!((base_gfn + npages <= s->base_gfn) ||
- (base_gfn >= s->base_gfn + s->npages)))
+ if (!((base_gfn + npages <= slot->base_gfn) ||
+ (base_gfn >= slot->base_gfn + slot->npages)))
goto out_free;
}