From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: [PATCH v2 10/10] KVM MMU: optimize sync/update unsync-page Date: Sun, 25 Apr 2010 15:02:24 +0800 Message-ID: <4BD3E900.7030909@cn.fujitsu.com> References: <4BD3E306.4020202@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , KVM list , LKML To: Avi Kivity Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:59888 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753172Ab0DYHFc (ORCPT ); Sun, 25 Apr 2010 03:05:32 -0400 In-Reply-To: <4BD3E306.4020202@cn.fujitsu.com> Sender: kvm-owner@vger.kernel.org List-ID: invlpg only need update unsync page, sp->unsync and sp->unsync_children can help us to find it Now, a gfn may have many shadow pages, when one sp need be synced, we write protect sp->gfn and sync this sp but we keep other shadow pages asynchronous So, while gfn happen page fault, let it not touch unsync page, the unsync page only updated at invlpg/flush TLB time Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 3 ++- arch/x86/kvm/paging_tmpl.h | 23 +++++++++++------------ 2 files changed, 13 insertions(+), 13 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index add4658..3886207 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2697,7 +2697,8 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, restart: hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) { - if (sp->gfn != gfn || sp->role.direct || sp->role.invalid) + if (sp->gfn != gfn || sp->role.direct || sp->role.invalid || + sp->unsync) continue; pte_size = sp->role.cr4_pae ? 8 : 4; misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 38b4d23..b4fb737 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -474,16 +474,16 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) level = iterator.level; sptep = iterator.sptep; + sp = page_header(__pa(sptep)); if (is_last_spte(*sptep, level)) { - sp = page_header(__pa(sptep)); - - if (PTTYPE == 32) { - if (level == PT_DIRECTORY_LEVEL) - offset = PAGE_SHIFT - 4; - else - offset = PT64_LEVEL_BITS; - offset = sp->role.quadrant << offset; - } + if (!sp->unsync) + break; + + WARN_ON(level != PT_PAGE_TABLE_LEVEL); + + if (PTTYPE == 32) + offset = sp->role.quadrant << PT64_LEVEL_BITS; + gfn = sp->gfn; offset = (sptep - sp->spt + offset) * sizeof(pt_element_t); @@ -498,7 +498,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) break; } - if (!is_shadow_present_pte(*sptep)) + if (!is_shadow_present_pte(*sptep) || !sp->unsync_children) break; } @@ -520,8 +520,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) mmu_guess_page_from_pte_write(vcpu, gfn_to_gpa(gfn) + offset, gentry); spin_lock(&vcpu->kvm->mmu_lock); - if (atomic_read(&vcpu->kvm->arch.invlpg_counter) == invlpg_counter && - sp->role.level == PT_PAGE_TABLE_LEVEL) { + if (atomic_read(&vcpu->kvm->arch.invlpg_counter) == invlpg_counter) { ++vcpu->kvm->stat.mmu_pte_updated; FNAME(update_pte)(vcpu, sp, sptep, &gentry); } -- 1.6.1.2