From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kai Huang Subject: Re: [PATCH v2 09/11] KVM: MMU: simplify mmu_need_write_protect Date: Thu, 24 Dec 2015 17:21:58 +0800 Message-ID: <567BB936.7060705@linux.intel.com> References: <1450869954-30273-1-git-send-email-guangrong.xiao@linux.intel.com> <1450869954-30273-10-git-send-email-guangrong.xiao@linux.intel.com> <567BAE8E.6080400@linux.intel.com> <567BB6B9.3000200@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, jike.song@intel.com To: Xiao Guangrong , pbonzini@redhat.com Return-path: In-Reply-To: <567BB6B9.3000200@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 12/24/2015 05:11 PM, Xiao Guangrong wrote: > > > On 12/24/2015 04:36 PM, Kai Huang wrote: >> >> >> On 12/23/2015 07:25 PM, Xiao Guangrong wrote: >>> Now, all non-leaf shadow page are page tracked, if gfn is not tracked >>> there is no non-leaf shadow page of gfn is existed, we can directly >>> make the shadow page of gfn to unsync >>> >>> Signed-off-by: Xiao Guangrong >>> --- >>> arch/x86/kvm/mmu.c | 26 ++++++++------------------ >>> 1 file changed, 8 insertions(+), 18 deletions(-) >>> >>> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >>> index 5a2ca73..f89e77f 100644 >>> --- a/arch/x86/kvm/mmu.c >>> +++ b/arch/x86/kvm/mmu.c >>> @@ -2461,41 +2461,31 @@ static void __kvm_unsync_page(struct >>> kvm_vcpu *vcpu, struct kvm_mmu_page *sp) >>> kvm_mmu_mark_parents_unsync(sp); >>> } >>> -static void kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn) >>> +static bool kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn, >>> + bool can_unsync) >>> { >>> struct kvm_mmu_page *s; >>> for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn) { >>> + if (!can_unsync) >>> + return true; >>> + >>> if (s->unsync) >>> continue; >>> WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL); >>> __kvm_unsync_page(vcpu, s); >>> } >>> + >>> + return false; >>> } >> I hate to say but it looks odd to me that kvm_unsync_pages takes a >> bool parameter called can_unsync, >> and return a bool (which looks like suggesting whether the unsync has >> succeeded or not). How about >> calling __kvm_unsync_pages directly in mmu_need_write_protect, and >> leave kvm_unsync_pages unchanged >> (or even remove it as looks it is used nowhere else) ? But again it's >> to you and Paolo. >> > > Make senses, the updated version is attached, count you review it? Sure and it looks good to me. Thanks, -Kai