Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755660Ab0KDKcQ (ORCPT ); Thu, 4 Nov 2010 06:32:16 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:55897 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753271Ab0KDKcN (ORCPT ); Thu, 4 Nov 2010 06:32:13 -0400 Message-ID: <4CD28CB4.9000906@cn.fujitsu.com> Date: Thu, 04 Nov 2010 18:36:36 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.11) Gecko/20100713 Thunderbird/3.0.6 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , Gleb Natapov , LKML , KVM Subject: [PATCH 3/3] KVM: MMU: retry #PF for softmmu References: <4CD28B5F.1040205@cn.fujitsu.com> In-Reply-To: <4CD28B5F.1040205@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-04 18:32:42, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-04 18:32:43, Serialize complete at 2010-11-04 18:32:43 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5751 Lines: 184 Retry #PF for softmmu only when the current vcpu has the same root shadow page as the time when #PF occurs. it means they have same paging environment. Signed-off-by: Xiao Guangrong --- arch/x86/include/asm/kvm_host.h | 6 ++++++ arch/x86/kvm/mmu.c | 33 ++++++++++++++++++++++++++++++++- arch/x86/kvm/x86.c | 16 ++++++++++++++-- virt/kvm/async_pf.c | 1 + 4 files changed, 53 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7f20f2c..b99ef7d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -192,6 +192,8 @@ struct kvm_mmu_page { struct list_head link; struct hlist_node hash_link; + struct kref apfs_counter; + /* * The following two entries are used to key the shadow page in the * hash table. @@ -600,6 +602,7 @@ struct kvm_x86_ops { struct kvm_arch_async_pf { u32 token; gfn_t gfn; + struct kvm_mmu_page *root_sp; }; extern struct kvm_x86_ops *kvm_x86_ops; @@ -697,6 +700,8 @@ void kvm_inject_nmi(struct kvm_vcpu *vcpu); int fx_init(struct kvm_vcpu *vcpu); +struct kvm_mmu_page *get_vcpu_root_sp(struct kvm_vcpu *vcpu, gva_t gva); +void kvm_mmu_release_apf_sp(struct kvm_mmu_page *sp); void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu); void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, int bytes, @@ -822,6 +827,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work); bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu); +void kvm_arch_clear_async_pf(struct kvm_async_pf *work); extern bool kvm_find_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn); #endif /* _ASM_X86_KVM_HOST_H */ diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index f3fad4f..60cc9f9 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -993,6 +993,19 @@ static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, int nr) percpu_counter_add(&kvm_total_used_mmu_pages, nr); } +static void free_shadow_page(struct kref *kref) +{ + struct kvm_mmu_page *sp; + + sp = container_of(kref, struct kvm_mmu_page, apfs_counter); + kmem_cache_free(mmu_page_header_cache, sp); +} + +void kvm_mmu_release_apf_sp(struct kvm_mmu_page *sp) +{ + kref_put(&sp->apfs_counter, free_shadow_page);; +} + static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) { ASSERT(is_empty_shadow_page(sp->spt)); @@ -1001,7 +1014,7 @@ static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) __free_page(virt_to_page(sp->spt)); if (!sp->role.direct) __free_page(virt_to_page(sp->gfns)); - kmem_cache_free(mmu_page_header_cache, sp); + kvm_mmu_release_apf_sp(sp); kvm_mod_used_mmu_pages(kvm, -1); } @@ -1026,6 +1039,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, sp->multimapped = 0; sp->parent_pte = parent_pte; kvm_mod_used_mmu_pages(vcpu->kvm, +1); + kref_init(&sp->apfs_counter); return sp; } @@ -2597,11 +2611,28 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, error_code & PFERR_WRITE_MASK, gfn); } +struct kvm_mmu_page *get_vcpu_root_sp(struct kvm_vcpu *vcpu, gva_t gva) +{ + struct kvm_shadow_walk_iterator iterator; + bool ret; + + shadow_walk_init(&iterator, vcpu, gva); + ret = shadow_walk_okay(&iterator); + WARN_ON(!ret); + + return page_header(__pa(iterator.sptep)); +} + static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn) { struct kvm_arch_async_pf arch; + arch.token = (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; arch.gfn = gfn; + if (!tdp_enabled) { + arch.root_sp = get_vcpu_root_sp(vcpu, gva); + kref_get(&arch.root_sp->apfs_counter); + } return kvm_setup_async_pf(vcpu, gva, gfn, &arch); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index aacc5eb..72d672f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6174,14 +6174,17 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) { int r; - if (!tdp_enabled || is_error_page(work->page)) + if (is_error_page(work->page)) return; r = kvm_mmu_reload(vcpu); + if (unlikely(r)) return; - vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true); + if (tdp_enabled || + get_vcpu_root_sp(vcpu, work->gva) == work->arch.root_sp) + vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true); } static inline u32 kvm_async_pf_hash_fn(gfn_t gfn) @@ -6269,10 +6272,19 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu, } } +void kvm_arch_clear_async_pf(struct kvm_async_pf *work) +{ + if (!tdp_enabled) + kvm_mmu_release_apf_sp(work->arch.root_sp); +} + void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) { trace_kvm_async_pf_ready(work->arch.token, work->gva); + + kvm_arch_clear_async_pf(work); + if (is_error_page(work->page)) work->arch.token = ~0; /* broadcast wakeup */ else diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index 74268b4..c3d4788 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -101,6 +101,7 @@ void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu) typeof(*work), queue); cancel_work_sync(&work->work); list_del(&work->queue); + kvm_arch_clear_async_pf(work); if (!work->done) /* work was canceled */ kmem_cache_free(async_pf_cache, work); } -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/