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authorXiao Guangrong <guangrong.xiao@linux.intel.com>2016-02-24 09:46:06 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2016-03-04 12:35:24 +0100
commite23d3fef83df8e303fded0ab55b379beec0dd604 (patch)
tree3dd0a917c2639a42ecdcf55ad6871cb2f004ba6c /arch
parent0a47cd85833e56574a926cad309726f4f7859544 (diff)
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/mmu.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 609fa5322f6a..0a4dc9b54181 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -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);