KVM: MMU: check kvm_mmu_pages and mmu_page_path indices

Give a special invalid index to the root of the walk, so that we
can check the consistency of kvm_mmu_pages and mmu_page_path.

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
[Extracted from a bigger patch proposed by Guangrong. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Xiao Guangrong 2016-02-24 09:46:06 +01:00 committed by Paolo Bonzini
parent 0a47cd8583
commit e23d3fef83

View file

@ -1870,6 +1870,8 @@ static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
return nr_unsync_leaf;
}
#define INVALID_INDEX (-1)
static int mmu_unsync_walk(struct kvm_mmu_page *sp,
struct kvm_mmu_pages *pvec)
{
@ -1877,7 +1879,7 @@ static int mmu_unsync_walk(struct kvm_mmu_page *sp,
if (!sp->unsync_children)
return 0;
mmu_pages_add(pvec, sp, 0);
mmu_pages_add(pvec, sp, INVALID_INDEX);
return __mmu_unsync_walk(sp, pvec);
}
@ -2026,6 +2028,8 @@ static int mmu_pages_first(struct kvm_mmu_pages *pvec,
if (pvec->nr == 0)
return 0;
WARN_ON(pvec->page[0].idx != INVALID_INDEX);
sp = pvec->page[0].sp;
level = sp->role.level;
WARN_ON(level == PT_PAGE_TABLE_LEVEL);
@ -2050,6 +2054,7 @@ static void mmu_pages_clear_parents(struct mmu_page_path *parents)
if (!sp)
return;
WARN_ON(idx == INVALID_INDEX);
clear_unsync_child_bit(sp, idx);
level++;
} while (!sp->unsync_children);