[v2,08/22] KVM: MMU: optimize to handle dirty bit

Message ID	4E01FCBF.1030005@cn.fujitsu.com (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p5METa4e004450 for <patchwork-kvm@patchwork.kernel.org>; Wed, 22 Jun 2011 14:29:37 GMT Message-ID: <4E01FCBF.1030005@cn.fujitsu.com> Date: Wed, 22 Jun 2011 22:31:27 +0800 From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc15 Thunderbird/3.1.10 MIME-Version: 1.0 To: Avi Kivity <avi@redhat.com> CC: Marcelo Tosatti <mtosatti@redhat.com>, LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org> Subject: [PATCH v2 08/22] KVM: MMU: optimize to handle dirty bit References: <4E01FBC9.3020009@cn.fujitsu.com> In-Reply-To: <4E01FBC9.3020009@cn.fujitsu.com> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 7f53210..9e35577 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1923,7 +1923,7 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn, static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access, int user_fault, - int write_fault, int dirty, int level, + int write_fault, int level, gfn_t gfn, pfn_t pfn, bool speculative, bool can_unsync, bool host_writable) { @@ -1938,8 +1938,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, spte = PT_PRESENT_MASK; if (!speculative) spte |= shadow_accessed_mask; - if (!dirty) - pte_access &= ~ACC_WRITE_MASK; + if (pte_access & ACC_EXEC_MASK) spte |= shadow_x_mask; else @@ -2023,7 +2022,7 @@ done: static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pt_access, unsigned pte_access, - int user_fault, int write_fault, int dirty, + int user_fault, int write_fault, int *ptwrite, int level, gfn_t gfn, pfn_t pfn, bool speculative, bool host_writable) @@ -2059,7 +2058,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, } if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault, - dirty, level, gfn, pfn, speculative, true, + level, gfn, pfn, speculative, true, host_writable)) { if (write_fault) *ptwrite = 1; @@ -2129,7 +2128,7 @@ static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, for (i = 0; i < ret; i++, gfn++, start++) mmu_set_spte(vcpu, start, ACC_ALL, - access, 0, 0, 1, NULL, + access, 0, 0, NULL, sp->role.level, gfn, page_to_pfn(pages[i]), true, true); @@ -2193,7 +2192,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, unsigned pte_access = ACC_ALL; mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, pte_access, - 0, write, 1, &pt_write, + 0, write, &pt_write, level, gfn, pfn, prefault, map_writable); direct_pte_prefetch(vcpu, iterator.sptep); ++vcpu->stat.pf_fixed; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 13978dc..e06c9e4 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -101,11 +101,15 @@ static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, return (ret != orig_pte); } -static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte) +static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte, + bool last) { unsigned access; access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK; + if (last && !is_dirty_gpte(gpte)) + access &= ~ACC_WRITE_MASK; + #if PTTYPE == 64 if (vcpu->arch.mmu.nx) access &= ~(gpte >> PT64_NX_SHIFT); @@ -227,8 +231,6 @@ walk: pte |= PT_ACCESSED_MASK; } - pte_access = pt_access & FNAME(gpte_access)(vcpu, pte); - walker->ptes[walker->level - 1] = pte; if ((walker->level == PT_PAGE_TABLE_LEVEL) || @@ -269,7 +271,7 @@ walk: break; } - pt_access = pte_access; + pt_access &= FNAME(gpte_access)(vcpu, pte, false); --walker->level; } @@ -293,6 +295,7 @@ walk: walker->ptes[walker->level - 1] = pte; } + pte_access = pt_access & FNAME(gpte_access)(vcpu, pte, true); walker->pt_access = pt_access; walker->pte_access = pte_access; pgprintk("%s: pte %llx pte_access %x pt_access %x\n", @@ -373,7 +376,7 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, return; pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte); - pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte); + pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte, true); pfn = gfn_to_pfn_atomic(vcpu->kvm, gpte_to_gfn(gpte)); if (is_error_pfn(pfn)) { kvm_release_pfn_clean(pfn); @@ -385,7 +388,7 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, * vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1). */ mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0, - is_dirty_gpte(gpte), NULL, PT_PAGE_TABLE_LEVEL, + NULL, PT_PAGE_TABLE_LEVEL, gpte_to_gfn(gpte), pfn, true, true); } @@ -436,7 +439,6 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, unsigned pte_access; gfn_t gfn; pfn_t pfn; - bool dirty; if (spte == sptep) continue; @@ -449,18 +451,18 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte)) continue; - pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte); + pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte, + true); gfn = gpte_to_gfn(gpte); - dirty = is_dirty_gpte(gpte); pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn, - (pte_access & ACC_WRITE_MASK) && dirty); + pte_access & ACC_WRITE_MASK); if (is_error_pfn(pfn)) { kvm_release_pfn_clean(pfn); break; } mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0, - dirty, NULL, PT_PAGE_TABLE_LEVEL, gfn, + NULL, PT_PAGE_TABLE_LEVEL, gfn, pfn, true, true); } } @@ -476,7 +478,6 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, { unsigned access = gw->pt_access; struct kvm_mmu_page *sp = NULL; - bool dirty = is_dirty_gpte(gw->ptes[gw->level - 1]); int top_level; unsigned direct_access; struct kvm_shadow_walk_iterator it; @@ -485,8 +486,6 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, return NULL; direct_access = gw->pt_access & gw->pte_access; - if (!dirty) - direct_access &= ~ACC_WRITE_MASK; top_level = vcpu->arch.mmu.root_level; if (top_level == PT32E_ROOT_LEVEL) @@ -545,7 +544,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, } mmu_set_spte(vcpu, it.sptep, access, gw->pte_access & access, - user_fault, write_fault, dirty, ptwrite, it.level, + user_fault, write_fault, ptwrite, it.level, gw->gfn, pfn, prefault, map_writable); FNAME(pte_prefetch)(vcpu, gw, it.sptep); @@ -628,17 +627,9 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, return 0; /* mmio */ - if (is_error_pfn(pfn)) { - unsigned access = walker.pte_access; - bool dirty = is_dirty_gpte(walker.ptes[walker.level - 1]); - - if (dirty) - access &= ~ACC_WRITE_MASK; - + if (is_error_pfn(pfn)) return kvm_handle_bad_page(vcpu, mmu_is_nested(vcpu) ? 0 : - addr, access, walker.gfn, pfn); - } - + addr, walker.pte_access, walker.gfn, pfn); spin_lock(&vcpu->kvm->mmu_lock); if (mmu_notifier_retry(vcpu, mmu_seq)) goto out_unlock; @@ -855,11 +846,12 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) } nr_present++; - pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte); + pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte, + true); host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE; set_spte(vcpu, &sp->spt[i], pte_access, 0, 0, - is_dirty_gpte(gpte), PT_PAGE_TABLE_LEVEL, gfn, + PT_PAGE_TABLE_LEVEL, gfn, spte_to_pfn(sp->spt[i]), true, false, host_writable); }

[v2,08/22] KVM: MMU: optimize to handle dirty bit

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Patch