Re: [PATCH 1/3 v2] KVM MMU: make kvm_mmu_zap_page() return the number of zapped sp in total.

[Marcelo Tosatti <mtosatti@redhat.com>]

On Fri, Apr 23, 2010 at 01:58:22PM +0800, Gui Jianfeng wrote:
> Currently, in kvm_mmu_change_mmu_pages(kvm, page), "used_pages--" is  performed after calling
> kvm_mmu_zap_page() in spite of that whether "page" is actually reclaimed. Because root sp won't 
> be reclaimed by kvm_mmu_zap_page(). So making kvm_mmu_zap_page() return total number of reclaimed 
> sp makes more sense. A new flag is put into kvm_mmu_zap_page() to indicate whether the top page is
> reclaimed.
> 
> Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
> ---
>  arch/x86/kvm/mmu.c |   53 +++++++++++++++++++++++++++++++++++----------------
>  1 files changed, 36 insertions(+), 17 deletions(-)

Gui, 

There will be only a few pinned roots, and there is no need for
kvm_mmu_change_mmu_pages to be precise at that level (pages will be
reclaimed through kvm_unmap_hva eventually).