From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH v4 3/6] KVM: MMU: introduce kvm_clear_all_lpage_info Date: Fri, 03 May 2013 13:57:38 +0800 Message-ID: <518351D2.9050806@linux.vnet.ibm.com> References: <1367032402-13729-1-git-send-email-xiaoguangrong@linux.vnet.ibm.com> <1367032402-13729-4-git-send-email-xiaoguangrong@linux.vnet.ibm.com> <20130503111531.b288fca3287c5f892436ade4@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: mtosatti@redhat.com, gleb@redhat.com, avi.kivity@gmail.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org To: Takuya Yoshikawa Return-path: In-Reply-To: <20130503111531.b288fca3287c5f892436ade4@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 05/03/2013 10:15 AM, Takuya Yoshikawa wrote: > On Sat, 27 Apr 2013 11:13:19 +0800 > Xiao Guangrong wrote: > >> This function is used to reset the large page info of all guest pages >> which will be used in later patch >> >> Signed-off-by: Xiao Guangrong >> --- >> arch/x86/kvm/x86.c | 25 +++++++++++++++++++++++++ >> arch/x86/kvm/x86.h | 2 ++ >> 2 files changed, 27 insertions(+), 0 deletions(-) >> >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index 52b4e97..8e4494c 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -6951,6 +6951,31 @@ static void memslot_set_lpage_disallowed(struct kvm_memory_slot *slot, >> } >> } >> >> +static void clear_memslot_lpage_info(struct kvm_memory_slot *slot) >> +{ >> + int i; >> + >> + for (i = 1; i < KVM_NR_PAGE_SIZES; ++i) { >> + int lpages; >> + int level = i + 1; >> + >> + lpages = gfn_to_index(slot->base_gfn + slot->npages - 1, >> + slot->base_gfn, level) + 1; >> + >> + memset(slot->arch.lpage_info[i - 1], 0, >> + sizeof(*slot->arch.lpage_info[i - 1])); >> + memslot_set_lpage_disallowed(slot, slot->npages, i, lpages); > > This does something other than clearing. Aha, this API *clears* the count set by kvm mmu. It is meaningful enough, i think.