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Commit e23d3fef authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Paolo Bonzini
Browse files

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: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
[Extracted from a bigger patch proposed by Guangrong. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 0a47cd85

arch/x86/kvm/mmu.c

+6 −1
Original line number Diff line number Diff line
@@ -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);