From patchwork Wed Jun 22 14:33:15 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiao Guangrong X-Patchwork-Id: 905382 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p5MEVpcG027788 for ; Wed, 22 Jun 2011 14:31:51 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758060Ab1FVObV (ORCPT ); Wed, 22 Jun 2011 10:31:21 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:64224 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1757922Ab1FVObS (ORCPT ); Wed, 22 Jun 2011 10:31:18 -0400 Received: from tang.cn.fujitsu.com (tang.cn.fujitsu.com [10.167.250.3]) by song.cn.fujitsu.com (Postfix) with ESMTP id 7B0D5170080; Wed, 22 Jun 2011 22:31:15 +0800 (CST) Received: from mailserver.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id p5MEVEDD001890; Wed, 22 Jun 2011 22:31:14 +0800 Received: from localhost.localdomain ([10.167.225.99]) by mailserver.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.1FP4) with ESMTP id 2011062222305054-642013 ; Wed, 22 Jun 2011 22:30:50 +0800 Message-ID: <4E01FD2B.5090008@cn.fujitsu.com> Date: Wed, 22 Jun 2011 22:33:15 +0800 From: Xiao Guangrong 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 CC: Marcelo Tosatti , LKML , KVM Subject: [PATCH v2 13/22] KVM: MMU: remove bypass_guest_pf References: <4E01FBC9.3020009@cn.fujitsu.com> In-Reply-To: <4E01FBC9.3020009@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-06-22 22:30:50, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-06-22 22:30:50, Serialize complete at 2011-06-22 22:30:50 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 22 Jun 2011 14:31:51 +0000 (UTC) The idea is from Avi: | Maybe it's time to kill off bypass_guest_pf=1. It's not as effective as | it used to be, since unsync pages always use shadow_trap_nonpresent_pte, | and since we convert between the two nonpresent_ptes during sync and unsync. Signed-off-by: Xiao Guangrong --- Documentation/kernel-parameters.txt | 4 -- arch/x86/include/asm/kvm_host.h | 3 - arch/x86/kvm/mmu.c | 83 ++++++++++------------------------- arch/x86/kvm/mmu_audit.c | 12 ----- arch/x86/kvm/paging_tmpl.h | 51 +++------------------ arch/x86/kvm/vmx.c | 11 +---- arch/x86/kvm/x86.c | 1 - 7 files changed, 33 insertions(+), 132 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index fd248a31..a06e4f1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1159,10 +1159,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. for all guests. Default is 1 (enabled) if in 64bit or 32bit-PAE mode - kvm-intel.bypass_guest_pf= - [KVM,Intel] Disables bypassing of guest page faults - on Intel chips. Default is 1 (enabled) - kvm-intel.ept= [KVM,Intel] Disable extended page tables (virtualized MMU) support on capable Intel chips. Default is 1 (enabled) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7b0834a..42e577d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -266,8 +266,6 @@ struct kvm_mmu { gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva, u32 access, struct x86_exception *exception); gpa_t (*translate_gpa)(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access); - void (*prefetch_page)(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *page); int (*sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp); void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva); @@ -638,7 +636,6 @@ void kvm_mmu_module_exit(void); void kvm_mmu_destroy(struct kvm_vcpu *vcpu); int kvm_mmu_create(struct kvm_vcpu *vcpu); int kvm_mmu_setup(struct kvm_vcpu *vcpu); -void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte); void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, u64 dirty_mask, u64 nx_mask, u64 x_mask); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index c6fabf0..2c7b7a0 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -186,8 +186,6 @@ static struct kmem_cache *pte_list_desc_cache; static struct kmem_cache *mmu_page_header_cache; static struct percpu_counter kvm_total_used_mmu_pages; -static u64 __read_mostly shadow_trap_nonpresent_pte; -static u64 __read_mostly shadow_notrap_nonpresent_pte; static u64 __read_mostly shadow_nx_mask; static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */ static u64 __read_mostly shadow_user_mask; @@ -199,13 +197,6 @@ static inline u64 rsvd_bits(int s, int e) return ((1ULL << (e - s + 1)) - 1) << s; } -void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte) -{ - shadow_trap_nonpresent_pte = trap_pte; - shadow_notrap_nonpresent_pte = notrap_pte; -} -EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes); - void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, u64 dirty_mask, u64 nx_mask, u64 x_mask) { @@ -229,8 +220,7 @@ static int is_nx(struct kvm_vcpu *vcpu) static int is_shadow_present_pte(u64 pte) { - return pte != shadow_trap_nonpresent_pte - && pte != shadow_notrap_nonpresent_pte; + return pte != 0ull; } static int is_large_pte(u64 pte) @@ -777,9 +767,9 @@ static int set_spte_track_bits(u64 *sptep, u64 new_spte) return 1; } -static void drop_spte(struct kvm *kvm, u64 *sptep, u64 new_spte) +static void drop_spte(struct kvm *kvm, u64 *sptep) { - if (set_spte_track_bits(sptep, new_spte)) + if (set_spte_track_bits(sptep, 0ull)) rmap_remove(kvm, sptep); } @@ -814,8 +804,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn) BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)); pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn); if (is_writable_pte(*spte)) { - drop_spte(kvm, spte, - shadow_trap_nonpresent_pte); + drop_spte(kvm, spte); --kvm->stat.lpages; spte = NULL; write_protected = 1; @@ -836,7 +825,7 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, while ((spte = rmap_next(kvm, rmapp, NULL))) { BUG_ON(!(*spte & PT_PRESENT_MASK)); rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte); - drop_spte(kvm, spte, shadow_trap_nonpresent_pte); + drop_spte(kvm, spte); need_tlb_flush = 1; } return need_tlb_flush; @@ -858,7 +847,7 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte, *spte); need_flush = 1; if (pte_write(*ptep)) { - drop_spte(kvm, spte, shadow_trap_nonpresent_pte); + drop_spte(kvm, spte); spte = rmap_next(kvm, rmapp, NULL); } else { new_spte = *spte &~ (PT64_BASE_ADDR_MASK); @@ -1088,7 +1077,7 @@ static void drop_parent_pte(struct kvm_mmu_page *sp, u64 *parent_pte) { mmu_page_remove_parent_pte(sp, parent_pte); - __set_spte(parent_pte, shadow_trap_nonpresent_pte); + __set_spte(parent_pte, 0ull); } static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, @@ -1130,15 +1119,6 @@ static void mark_unsync(u64 *spte) kvm_mmu_mark_parents_unsync(sp); } -static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp) -{ - int i; - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - sp->spt[i] = shadow_trap_nonpresent_pte; -} - static int nonpaging_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) { @@ -1420,6 +1400,14 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu, } } +static void init_shadow_page_table(struct kvm_mmu_page *sp) +{ + int i; + + for (i = 0; i < PT64_ENT_PER_PAGE; ++i) + sp->spt[i] = 0ull; +} + static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gaddr, @@ -1482,10 +1470,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, account_shadowed(vcpu->kvm, gfn); } - if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte) - vcpu->arch.mmu.prefetch_page(vcpu, sp); - else - nonpaging_prefetch_page(vcpu, sp); + init_shadow_page_table(sp); trace_kvm_mmu_get_page(sp, true); return sp; } @@ -1546,7 +1531,7 @@ static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp) static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) { if (is_large_pte(*sptep)) { - drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte); + drop_spte(vcpu->kvm, sptep); kvm_flush_remote_tlbs(vcpu->kvm); } } @@ -1582,13 +1567,13 @@ static void mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, pte = *spte; if (is_shadow_present_pte(pte)) { if (is_last_spte(pte, sp->role.level)) - drop_spte(kvm, spte, shadow_trap_nonpresent_pte); + drop_spte(kvm, spte); else { child = page_header(pte & PT64_BASE_ADDR_MASK); drop_parent_pte(child, spte); } } - __set_spte(spte, shadow_trap_nonpresent_pte); + if (is_large_pte(pte)) --kvm->stat.lpages; } @@ -1769,20 +1754,6 @@ static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn) __set_bit(slot, sp->slot_bitmap); } -static void mmu_convert_notrap(struct kvm_mmu_page *sp) -{ - int i; - u64 *pt = sp->spt; - - if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte) - return; - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { - if (pt[i] == shadow_notrap_nonpresent_pte) - __set_spte(&pt[i], shadow_trap_nonpresent_pte); - } -} - /* * The function is based on mtrr_type_lookup() in * arch/x86/kernel/cpu/mtrr/generic.c @@ -1895,7 +1866,6 @@ static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) sp->unsync = 1; kvm_mmu_mark_parents_unsync(sp); - mmu_convert_notrap(sp); } static void kvm_unsync_pages(struct kvm_vcpu *vcpu, gfn_t gfn) @@ -1980,7 +1950,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, if (level > PT_PAGE_TABLE_LEVEL && has_wrprotected_page(vcpu->kvm, gfn, level)) { ret = 1; - drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte); + drop_spte(vcpu->kvm, sptep); goto done; } @@ -2066,7 +2036,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, } else if (pfn != spte_to_pfn(*sptep)) { pgprintk("hfn old %llx new %llx\n", spte_to_pfn(*sptep), pfn); - drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte); + drop_spte(vcpu->kvm, sptep); kvm_flush_remote_tlbs(vcpu->kvm); } else was_rmapped = 1; @@ -2162,7 +2132,7 @@ static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, spte = sp->spt + i; for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { - if (*spte != shadow_trap_nonpresent_pte || spte == sptep) { + if (is_shadow_present_pte(*spte) || spte == sptep) { if (!start) continue; if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) @@ -2214,7 +2184,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, break; } - if (*iterator.sptep == shadow_trap_nonpresent_pte) { + if (!is_shadow_present_pte(*iterator.sptep)) { u64 base_addr = iterator.addr; base_addr &= PT64_LVL_ADDR_MASK(iterator.level); @@ -2748,7 +2718,6 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu, context->page_fault = nonpaging_page_fault; context->gva_to_gpa = nonpaging_gva_to_gpa; context->free = nonpaging_free; - context->prefetch_page = nonpaging_prefetch_page; context->sync_page = nonpaging_sync_page; context->invlpg = nonpaging_invlpg; context->update_pte = nonpaging_update_pte; @@ -2878,7 +2847,6 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, context->new_cr3 = paging_new_cr3; context->page_fault = paging64_page_fault; context->gva_to_gpa = paging64_gva_to_gpa; - context->prefetch_page = paging64_prefetch_page; context->sync_page = paging64_sync_page; context->invlpg = paging64_invlpg; context->update_pte = paging64_update_pte; @@ -2907,7 +2875,6 @@ static int paging32_init_context(struct kvm_vcpu *vcpu, context->page_fault = paging32_page_fault; context->gva_to_gpa = paging32_gva_to_gpa; context->free = paging_free; - context->prefetch_page = paging32_prefetch_page; context->sync_page = paging32_sync_page; context->invlpg = paging32_invlpg; context->update_pte = paging32_update_pte; @@ -2932,7 +2899,6 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) context->new_cr3 = nonpaging_new_cr3; context->page_fault = tdp_page_fault; context->free = nonpaging_free; - context->prefetch_page = nonpaging_prefetch_page; context->sync_page = nonpaging_sync_page; context->invlpg = nonpaging_invlpg; context->update_pte = nonpaging_update_pte; @@ -3453,8 +3419,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) continue; if (is_large_pte(pt[i])) { - drop_spte(kvm, &pt[i], - shadow_trap_nonpresent_pte); + drop_spte(kvm, &pt[i]); --kvm->stat.lpages; continue; } diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c index 5f6223b..2460a26 100644 --- a/arch/x86/kvm/mmu_audit.c +++ b/arch/x86/kvm/mmu_audit.c @@ -99,18 +99,6 @@ static void audit_mappings(struct kvm_vcpu *vcpu, u64 *sptep, int level) "level = %d\n", sp, level); return; } - - if (*sptep == shadow_notrap_nonpresent_pte) { - audit_printk(vcpu->kvm, "notrap spte in unsync " - "sp: %p\n", sp); - return; - } - } - - if (sp->role.direct && *sptep == shadow_notrap_nonpresent_pte) { - audit_printk(vcpu->kvm, "notrap spte in direct sp: %p\n", - sp); - return; } if (!is_shadow_present_pte(*sptep) || !is_last_spte(*sptep, level)) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 1e534e0..58a29d0 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -343,16 +343,11 @@ static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, u64 *spte, pt_element_t gpte) { - u64 nonpresent = shadow_trap_nonpresent_pte; - if (is_rsvd_bits_set(&vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL)) goto no_present; - if (!is_present_gpte(gpte)) { - if (!sp->unsync) - nonpresent = shadow_notrap_nonpresent_pte; + if (!is_present_gpte(gpte)) goto no_present; - } if (!(gpte & PT_ACCESSED_MASK)) goto no_present; @@ -360,7 +355,7 @@ static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu, return false; no_present: - drop_spte(vcpu->kvm, spte, nonpresent); + drop_spte(vcpu->kvm, spte); return true; } @@ -443,7 +438,7 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, if (spte == sptep) continue; - if (*spte != shadow_trap_nonpresent_pte) + if (is_shadow_present_pte(*spte)) continue; gpte = gptep[i]; @@ -693,11 +688,10 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) if (is_shadow_present_pte(*sptep)) { if (is_large_pte(*sptep)) --vcpu->kvm->stat.lpages; - drop_spte(vcpu->kvm, sptep, - shadow_trap_nonpresent_pte); + drop_spte(vcpu->kvm, sptep); need_flush = 1; - } else - __set_spte(sptep, shadow_trap_nonpresent_pte); + } + break; } @@ -757,36 +751,6 @@ static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gva_t vaddr, return gpa; } -static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp) -{ - int i, j, offset, r; - pt_element_t pt[256 / sizeof(pt_element_t)]; - gpa_t pte_gpa; - - if (sp->role.direct - || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) { - nonpaging_prefetch_page(vcpu, sp); - return; - } - - pte_gpa = gfn_to_gpa(sp->gfn); - if (PTTYPE == 32) { - offset = sp->role.quadrant << PT64_LEVEL_BITS; - pte_gpa += offset * sizeof(pt_element_t); - } - - for (i = 0; i < PT64_ENT_PER_PAGE; i += ARRAY_SIZE(pt)) { - r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, pt, sizeof pt); - pte_gpa += ARRAY_SIZE(pt) * sizeof(pt_element_t); - for (j = 0; j < ARRAY_SIZE(pt); ++j) - if (r || is_present_gpte(pt[j])) - sp->spt[i+j] = shadow_trap_nonpresent_pte; - else - sp->spt[i+j] = shadow_notrap_nonpresent_pte; - } -} - /* * Using the cached information from sp->gfns is safe because: * - The spte has a reference to the struct page, so the pfn for a given gfn @@ -839,8 +803,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) } if (gfn != sp->gfns[i]) { - drop_spte(vcpu->kvm, &sp->spt[i], - shadow_trap_nonpresent_pte); + drop_spte(vcpu->kvm, &sp->spt[i]); vcpu->kvm->tlbs_dirty++; continue; } diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index f5b49c7..a644acb 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -49,9 +49,6 @@ MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); -static int __read_mostly bypass_guest_pf = 1; -module_param(bypass_guest_pf, bool, S_IRUGO); - static int __read_mostly enable_vpid = 1; module_param_named(vpid, enable_vpid, bool, 0444); @@ -3632,8 +3629,8 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx) vmcs_write32(PLE_WINDOW, ple_window); } - vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, !!bypass_guest_pf); - vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, !!bypass_guest_pf); + vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, 0); + vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, 0); vmcs_write32(CR3_TARGET_COUNT, 0); /* 22.2.1 */ vmcs_write16(HOST_FS_SELECTOR, 0); /* 22.2.4 */ @@ -7103,16 +7100,12 @@ static int __init vmx_init(void) vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_EIP, false); if (enable_ept) { - bypass_guest_pf = 0; kvm_mmu_set_mask_ptes(0ull, 0ull, 0ull, 0ull, VMX_EPT_EXECUTABLE_MASK); kvm_enable_tdp(); } else kvm_disable_tdp(); - if (bypass_guest_pf) - kvm_mmu_set_nonpresent_ptes(~0xffeull, 0ull); - return 0; out3: diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 40ffbc5..78d5519 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5065,7 +5065,6 @@ int kvm_arch_init(void *opaque) kvm_init_msr_list(); kvm_x86_ops = ops; - kvm_mmu_set_nonpresent_ptes(0ull, 0ull); kvm_mmu_set_mask_ptes(PT_USER_MASK, PT_ACCESSED_MASK, PT_DIRTY_MASK, PT64_NX_MASK, 0);