aboutsummaryrefslogtreecommitdiffstats
path: root/virt/kvm/kvm_main.c
diff options
context:
space:
mode:
authorTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>2010-04-12 19:35:35 +0900
committerAvi Kivity <avi@redhat.com>2010-04-20 13:06:55 +0300
commit87bf6e7de1134f48681fd2ce4b7c1ec45458cb6d (patch)
treeae8ce63cecab98c036c0d76422de42cf78e042f4 /virt/kvm/kvm_main.c
parent77662e0028c7c63e34257fda03ff9625c59d939d (diff)
downloadmrst-s0i3-test-87bf6e7de1134f48681fd2ce4b7c1ec45458cb6d.tar.gz
mrst-s0i3-test-87bf6e7de1134f48681fd2ce4b7c1ec45458cb6d.tar.xz
mrst-s0i3-test-87bf6e7de1134f48681fd2ce4b7c1ec45458cb6d.zip
KVM: fix the handling of dirty bitmaps to avoid overflows
Int is not long enough to store the size of a dirty bitmap. This patch fixes this problem with the introduction of a wrapper function to calculate the sizes of dirty bitmaps. Note: in mark_page_dirty(), we have to consider the fact that __set_bit() takes the offset as int, not long. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'virt/kvm/kvm_main.c')
-rw-r--r--virt/kvm/kvm_main.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5a0cd194dce..364daacafb5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -648,7 +648,7 @@ skip_lpage:
/* Allocate page dirty bitmap if needed */
if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
- unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
+ unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(&new);
new.dirty_bitmap = vmalloc(dirty_bytes);
if (!new.dirty_bitmap)
@@ -768,7 +768,7 @@ int kvm_get_dirty_log(struct kvm *kvm,
{
struct kvm_memory_slot *memslot;
int r, i;
- int n;
+ unsigned long n;
unsigned long any = 0;
r = -EINVAL;
@@ -780,7 +780,7 @@ int kvm_get_dirty_log(struct kvm *kvm,
if (!memslot->dirty_bitmap)
goto out;
- n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
+ n = kvm_dirty_bitmap_bytes(memslot);
for (i = 0; !any && i < n/sizeof(long); ++i)
any = memslot->dirty_bitmap[i];
@@ -1186,10 +1186,13 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
memslot = gfn_to_memslot_unaliased(kvm, gfn);
if (memslot && memslot->dirty_bitmap) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
+ unsigned long *p = memslot->dirty_bitmap +
+ rel_gfn / BITS_PER_LONG;
+ int offset = rel_gfn % BITS_PER_LONG;
/* avoid RMW */
- if (!generic_test_le_bit(rel_gfn, memslot->dirty_bitmap))
- generic___set_le_bit(rel_gfn, memslot->dirty_bitmap);
+ if (!generic_test_le_bit(offset, p))
+ generic___set_le_bit(offset, p);
}
}