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KVM: MMU: clear unsync_child_bitmap completely

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In current code, some page's unsync_child_bitmap is not cleared completely
in mmu_sync_children(), for example, if two PDPEs shard one PDT, one of
PDPE's unsync_child_bitmap is not cleared.

Currently, it not harm anything just little overload, but it's the prepare
work for the later patch

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Xiao Guangrong 2010-06-11 21:34:04 +08:00 committed by Avi Kivity
parent ebdea638df
commit 7a8f1a74e4
1 changed files with 27 additions and 22 deletions
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49
arch/x86/kvm/mmu.c
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@ -1149,33 +1149,38 @@ static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
int i, ret, nr_unsync_leaf = 0;
for_each_unsync_children(sp->unsync_child_bitmap, i) {
struct kvm_mmu_page *child;
u64 ent = sp->spt[i];
if (is_shadow_present_pte(ent) && !is_large_pte(ent)) {
struct kvm_mmu_page *child;
child = page_header(ent & PT64_BASE_ADDR_MASK);
if (!is_shadow_present_pte(ent) || is_large_pte(ent))
goto clear_child_bitmap;
if (child->unsync_children) {
if (mmu_pages_add(pvec, child, i))
return -ENOSPC;
child = page_header(ent & PT64_BASE_ADDR_MASK);
ret = __mmu_unsync_walk(child, pvec);
if (!ret) {
__clear_bit(i, sp->unsync_child_bitmap);
sp->unsync_children--;
WARN_ON((int)sp->unsync_children < 0);
} else if (ret > 0)
nr_unsync_leaf += ret;
else
return ret;
}
if (child->unsync_children) {
if (mmu_pages_add(pvec, child, i))
return -ENOSPC;
if (child->unsync) {
nr_unsync_leaf++;
if (mmu_pages_add(pvec, child, i))
return -ENOSPC;
}
}
ret = __mmu_unsync_walk(child, pvec);
if (!ret)
goto clear_child_bitmap;
else if (ret > 0)
nr_unsync_leaf += ret;
else
return ret;
} else if (child->unsync) {
nr_unsync_leaf++;
if (mmu_pages_add(pvec, child, i))
return -ENOSPC;
} else
goto clear_child_bitmap;
continue;
clear_child_bitmap:
__clear_bit(i, sp->unsync_child_bitmap);
sp->unsync_children--;
WARN_ON((int)sp->unsync_children < 0);
}