Re: [PATCH v2 01/22] KVM: MMU: fix walking shadow page table

Marcelo Tosatti
2011-06-22T17:13:36Z

On Wed, Jun 22, 2011 at 10:28:04PM +0800, Xiao Guangrong wrote:
> Properly check the last mapping, and do not walk to the next level if last spte
> is met
>
> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> ---
> arch/x86/kvm/mmu.c | 9 +++++----
> 1 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 9c629b5..f474e93 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -1517,10 +1517,6 @@ static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)
> if (iterator->level < PT_PAGE_TABLE_LEVEL)
> return false;
>
> - if (iterator->level == PT_PAGE_TABLE_LEVEL)

Change to >= PT_PAGE_TABLE_LEVEL, checks should be in shadow_walk_okay.

> - if (is_large_pte(*iterator->sptep))
> - return false;
> -
> iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);
> iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index;
> return true;