[v3,11/11] KVM: MMU: trace pte prefetch

Message ID	4C2AFBB8.7090605@cn.fujitsu.com (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.4/8.14.3) with ESMTP id o5U8DJh8026634 for <patchwork-kvm@patchwork.kernel.org>; Wed, 30 Jun 2010 08:13:19 GMT Message-ID: <4C2AFBB8.7090605@cn.fujitsu.com> Date: Wed, 30 Jun 2010 16:09:28 +0800 From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Avi Kivity <avi@redhat.com> CC: Marcelo Tosatti <mtosatti@redhat.com>, LKML <linux-kernel@vger.kernel.org>, KVM list <kvm@vger.kernel.org> Subject: [PATCH v3 11/11] KVM: MMU: trace pte prefetch References: <4C2AF9FA.9020601@cn.fujitsu.com> In-Reply-To: <4C2AF9FA.9020601@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index fadfafe..0894ed8 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -91,6 +91,12 @@ module_param(oos_shadow, bool, 0644); #define PTE_PREFETCH_NUM 16 +#define PREFETCH_SUCCESS 0 +#define PREFETCH_ERR_GFN2PFN 1 +#define PREFETCH_ERR_ALLOC_MEM 2 +#define PREFETCH_ERR_RSVD_BITS_SET 3 +#define PREFETCH_ERR_MMIO 4 + #define PT_FIRST_AVAIL_BITS_SHIFT 9 #define PT64_SECOND_AVAIL_BITS_SHIFT 52 @@ -2004,7 +2010,7 @@ static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, - u64 *start, u64 *end) + u64 *start, u64 *end, u64 address) { gfn_t gfn; struct page *pages[PTE_PREFETCH_NUM]; @@ -2015,36 +2021,52 @@ static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, int entry, j, ret; addr = gfn_to_hva_many(vcpu->kvm, gfn, &entry); - if (kvm_is_error_hva(addr)) + if (kvm_is_error_hva(addr)) { + trace_pte_prefetch(true, address, 0, + PREFETCH_ERR_MMIO); return -1; + } entry = min(entry, (int)(end - start)); ret = __get_user_pages_fast(addr, entry, 1, pages); - if (ret <= 0) + if (ret <= 0) { + trace_pte_prefetch(true, address, 0, + PREFETCH_ERR_GFN2PFN); return -1; + } - for (j = 0; j < ret; j++, gfn++, start++) + for (j = 0; j < ret; j++, gfn++, start++) { + trace_pte_prefetch(true, address, 0, + PREFETCH_SUCCESS); mmu_set_spte(vcpu, start, ACC_ALL, sp->role.access, 0, 0, 1, NULL, sp->role.level, gfn, page_to_pfn(pages[j]), true, false); + } - if (ret < entry) + if (ret < entry) { + trace_pte_prefetch(true, address, 0, + PREFETCH_ERR_GFN2PFN); return -1; + } } return 0; } static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp, u64 *sptep) + struct kvm_mmu_page *sp, u64 *sptep, + u64 addr) { u64 *start = NULL; int index, i, max; WARN_ON(!sp->role.direct); - if (pte_prefetch_topup_memory_cache(vcpu)) + if (pte_prefetch_topup_memory_cache(vcpu)) { + trace_pte_prefetch(true, addr, 0, + PREFETCH_ERR_ALLOC_MEM); return; + } index = sptep - sp->spt; i = index & ~(PTE_PREFETCH_NUM - 1); @@ -2056,7 +2078,8 @@ static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, if (*spte != shadow_trap_nonpresent_pte || spte == sptep) { if (!start) continue; - if (direct_pte_prefetch_many(vcpu, sp, start, spte) < 0) + if (direct_pte_prefetch_many(vcpu, sp, start, + spte, addr) < 0) break; start = NULL; } else if (!start) @@ -2064,7 +2087,7 @@ static void __direct_pte_prefetch(struct kvm_vcpu *vcpu, } } -static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) +static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep, u64 addr) { struct kvm_mmu_page *sp; @@ -2081,7 +2104,7 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep) if (sp->role.level > PT_PAGE_TABLE_LEVEL) return; - __direct_pte_prefetch(vcpu, sp, sptep); + __direct_pte_prefetch(vcpu, sp, sptep, addr); } static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, @@ -2097,7 +2120,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL, 0, write, 1, &pt_write, level, gfn, pfn, false, true); - direct_pte_prefetch(vcpu, iterator.sptep); + direct_pte_prefetch(vcpu, iterator.sptep, gfn << PAGE_SHIFT); ++vcpu->stat.pf_fixed; break; } diff --git a/arch/x86/kvm/mmutrace.h b/arch/x86/kvm/mmutrace.h index 3aab0f0..c07b6a6 100644 --- a/arch/x86/kvm/mmutrace.h +++ b/arch/x86/kvm/mmutrace.h @@ -195,6 +195,39 @@ DEFINE_EVENT(kvm_mmu_page_class, kvm_mmu_prepare_zap_page, TP_ARGS(sp) ); + +#define pte_prefetch_err \ + {PREFETCH_SUCCESS, "SUCCESS" }, \ + {PREFETCH_ERR_GFN2PFN, "ERR_GFN2PFN" }, \ + {PREFETCH_ERR_ALLOC_MEM, "ERR_ALLOC_MEM" }, \ + {PREFETCH_ERR_RSVD_BITS_SET, "ERR_RSVD_BITS_SET"}, \ + {PREFETCH_ERR_MMIO, "ERR_MMIO" } + +TRACE_EVENT( + pte_prefetch, + TP_PROTO(bool direct, u64 addr, u64 gpte, int err_code), + + TP_ARGS(direct, addr, gpte, err_code), + + TP_STRUCT__entry( + __field(bool, direct) + __field(u64, addr) + __field(u64, gpte) + __field(int, err_code) + ), + + TP_fast_assign( + __entry->direct = direct; + __entry->addr = addr; + __entry->gpte = gpte; + __entry->err_code = err_code; + ), + + TP_printk("%s address:%llx gpte:%llx %s", + __entry->direct ? "direct" : "indirect", + __entry->addr, __entry->gpte, + __print_symbolic(__entry->err_code, pte_prefetch_err)) + ); #endif /* _TRACE_KVMMMU_H */ #undef TRACE_INCLUDE_PATH diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 3e047b4..ec7f148 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -318,7 +318,7 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, } static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, - struct guest_walker *gw, u64 *sptep) + struct guest_walker *gw, u64 *sptep, u64 addr) { struct kvm_mmu_page *sp; pt_element_t *gptep; @@ -331,7 +331,7 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, return; if (sp->role.direct) - return __direct_pte_prefetch(vcpu, sp, sptep); + return __direct_pte_prefetch(vcpu, sp, sptep, addr); index = sptep - sp->spt; i = index & ~(PTE_PREFETCH_NUM - 1); @@ -339,8 +339,10 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, gptep = gw->prefetch_ptes; - if (pte_prefetch_topup_memory_cache(vcpu)) + if (pte_prefetch_topup_memory_cache(vcpu)) { + trace_pte_prefetch(false, addr, 0, PREFETCH_ERR_ALLOC_MEM); return; + } for (j = 0; i < max; i++, j++) { pt_element_t gpte; @@ -357,15 +359,21 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, gpte = gptep[j]; - if (is_rsvd_bits_set(vcpu, gpte, PT_PAGE_TABLE_LEVEL)) + if (is_rsvd_bits_set(vcpu, gpte, PT_PAGE_TABLE_LEVEL)) { + trace_pte_prefetch(false, addr, gpte, + PREFETCH_ERR_RSVD_BITS_SET); break; + } if (!(gpte & PT_ACCESSED_MASK)) continue; if (!is_present_gpte(gpte)) { - if (!sp->unsync) + if (!sp->unsync) { + trace_pte_prefetch(false, addr, gpte, + PREFETCH_SUCCESS); __set_spte(spte, shadow_notrap_nonpresent_pte); + } continue; } @@ -373,10 +381,13 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, pfn = gfn_to_pfn_atomic(vcpu->kvm, gfn); if (is_error_pfn(pfn)) { + trace_pte_prefetch(false, addr, gpte, + PREFETCH_ERR_GFN2PFN); kvm_release_pfn_clean(pfn); break; } + trace_pte_prefetch(false, addr, gpte, PREFETCH_SUCCESS); pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte); mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0, is_dirty_gpte(gpte), NULL, sp->role.level, gfn, @@ -420,7 +431,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, user_fault, write_fault, dirty, ptwrite, level, gw->gfn, pfn, false, true); - FNAME(pte_prefetch)(vcpu, gw, sptep); + FNAME(pte_prefetch)(vcpu, gw, sptep, addr); break; }

[v3,11/11] KVM: MMU: trace pte prefetch

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Patch