From c2d0ee46e6e633a3c23ecbcb9b03ad731906cd79 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Sun, 5 Apr 2009 14:54:47 -0300 Subject: [PATCH] KVM: MMU: remove global page optimization logic Complexity to fix it not worthwhile the gains, as discussed in http://article.gmane.org/gmane.comp.emulators.kvm.devel/28649. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 4 ---- arch/x86/kvm/mmu.c | 50 +++++------------------------------------ arch/x86/kvm/paging_tmpl.h | 6 ++--- arch/x86/kvm/x86.c | 4 ---- 4 files changed, 8 insertions(+), 56 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 3fc4623..0e3a7c6 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -213,7 +213,6 @@ struct kvm_mmu_page { int multimapped; /* More than one parent_pte? */ int root_count; /* Currently serving as active root */ bool unsync; - bool global; unsigned int unsync_children; union { u64 *parent_pte; /* !multimapped */ @@ -395,7 +394,6 @@ struct kvm_arch{ */ struct list_head active_mmu_pages; struct list_head assigned_dev_head; - struct list_head oos_global_pages; struct iommu_domain *iommu_domain; struct kvm_pic *vpic; struct kvm_ioapic *vioapic; @@ -425,7 +423,6 @@ struct kvm_vm_stat { u32 mmu_recycled; u32 mmu_cache_miss; u32 mmu_unsync; - u32 mmu_unsync_global; u32 remote_tlb_flush; u32 lpages; }; @@ -640,7 +637,6 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu); int kvm_mmu_load(struct kvm_vcpu *vcpu); void kvm_mmu_unload(struct kvm_vcpu *vcpu); void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu); -void kvm_mmu_sync_global(struct kvm_vcpu *vcpu); int kvm_emulate_hypercall(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index b582add..b39ec62 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1075,18 +1075,10 @@ static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn) return NULL; } -static void kvm_unlink_unsync_global(struct kvm *kvm, struct kvm_mmu_page *sp) -{ - list_del(&sp->oos_link); - --kvm->stat.mmu_unsync_global; -} - static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) { WARN_ON(!sp->unsync); sp->unsync = 0; - if (sp->global) - kvm_unlink_unsync_global(kvm, sp); --kvm->stat.mmu_unsync; } @@ -1249,7 +1241,6 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word); sp->gfn = gfn; sp->role = role; - sp->global = 0; hlist_add_head(&sp->hash_link, bucket); if (!direct) { if (rmap_write_protect(vcpu->kvm, gfn)) @@ -1647,11 +1638,7 @@ static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) ++vcpu->kvm->stat.mmu_unsync; sp->unsync = 1; - if (sp->global) { - list_add(&sp->oos_link, &vcpu->kvm->arch.oos_global_pages); - ++vcpu->kvm->stat.mmu_unsync_global; - } else - kvm_mmu_mark_parents_unsync(vcpu, sp); + kvm_mmu_mark_parents_unsync(vcpu, sp); mmu_convert_notrap(sp); return 0; @@ -1678,21 +1665,12 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn, static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, unsigned pte_access, int user_fault, int write_fault, int dirty, int largepage, - int global, gfn_t gfn, pfn_t pfn, bool speculative, + gfn_t gfn, pfn_t pfn, bool speculative, bool can_unsync) { u64 spte; int ret = 0; u64 mt_mask = shadow_mt_mask; - struct kvm_mmu_page *sp = page_header(__pa(shadow_pte)); - - if (!global && sp->global) { - sp->global = 0; - if (sp->unsync) { - kvm_unlink_unsync_global(vcpu->kvm, sp); - kvm_mmu_mark_parents_unsync(vcpu, sp); - } - } /* * We don't set the accessed bit, since we sometimes want to see @@ -1766,8 +1744,8 @@ set_pte: static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, unsigned pt_access, unsigned pte_access, int user_fault, int write_fault, int dirty, - int *ptwrite, int largepage, int global, - gfn_t gfn, pfn_t pfn, bool speculative) + int *ptwrite, int largepage, gfn_t gfn, + pfn_t pfn, bool speculative) { int was_rmapped = 0; int was_writeble = is_writeble_pte(*shadow_pte); @@ -1796,7 +1774,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, was_rmapped = 1; } if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault, - dirty, largepage, global, gfn, pfn, speculative, true)) { + dirty, largepage, gfn, pfn, speculative, true)) { if (write_fault) *ptwrite = 1; kvm_x86_ops->tlb_flush(vcpu); @@ -1844,7 +1822,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, || (largepage && iterator.level == PT_DIRECTORY_LEVEL)) { mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL, 0, write, 1, &pt_write, - largepage, 0, gfn, pfn, false); + largepage, gfn, pfn, false); ++vcpu->stat.pf_fixed; break; } @@ -2015,15 +1993,6 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu) } } -static void mmu_sync_global(struct kvm_vcpu *vcpu) -{ - struct kvm *kvm = vcpu->kvm; - struct kvm_mmu_page *sp, *n; - - list_for_each_entry_safe(sp, n, &kvm->arch.oos_global_pages, oos_link) - kvm_sync_page(vcpu, sp); -} - void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) { spin_lock(&vcpu->kvm->mmu_lock); @@ -2031,13 +2000,6 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) spin_unlock(&vcpu->kvm->mmu_lock); } -void kvm_mmu_sync_global(struct kvm_vcpu *vcpu) -{ - spin_lock(&vcpu->kvm->mmu_lock); - mmu_sync_global(vcpu); - spin_unlock(&vcpu->kvm->mmu_lock); -} - static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr) { return vaddr; diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 09782a9..258e459 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -268,8 +268,7 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page, kvm_get_pfn(pfn); mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0, gpte & PT_DIRTY_MASK, NULL, largepage, - gpte & PT_GLOBAL_MASK, gpte_to_gfn(gpte), - pfn, true); + gpte_to_gfn(gpte), pfn, true); } /* @@ -303,7 +302,6 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, user_fault, write_fault, gw->ptes[gw->level-1] & PT_DIRTY_MASK, ptwrite, largepage, - gw->ptes[gw->level-1] & PT_GLOBAL_MASK, gw->gfn, pfn, false); break; } @@ -592,7 +590,7 @@ 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); set_spte(vcpu, &sp->spt[i], pte_access, 0, 0, - is_dirty_pte(gpte), 0, gpte & PT_GLOBAL_MASK, gfn, + is_dirty_pte(gpte), 0, gfn, spte_to_pfn(sp->spt[i]), true, false); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bb04f11..b5ac1b7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -108,7 +108,6 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "mmu_recycled", VM_STAT(mmu_recycled) }, { "mmu_cache_miss", VM_STAT(mmu_cache_miss) }, { "mmu_unsync", VM_STAT(mmu_unsync) }, - { "mmu_unsync_global", VM_STAT(mmu_unsync_global) }, { "remote_tlb_flush", VM_STAT(remote_tlb_flush) }, { "largepages", VM_STAT(lpages) }, { NULL } @@ -322,7 +321,6 @@ void kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) kvm_x86_ops->set_cr0(vcpu, cr0); vcpu->arch.cr0 = cr0; - kvm_mmu_sync_global(vcpu); kvm_mmu_reset_context(vcpu); return; } @@ -371,7 +369,6 @@ void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) kvm_x86_ops->set_cr4(vcpu, cr4); vcpu->arch.cr4 = cr4; vcpu->arch.mmu.base_role.cr4_pge = (cr4 & X86_CR4_PGE) && !tdp_enabled; - kvm_mmu_sync_global(vcpu); kvm_mmu_reset_context(vcpu); } EXPORT_SYMBOL_GPL(kvm_set_cr4); @@ -4364,7 +4361,6 @@ struct kvm *kvm_arch_create_vm(void) return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); - INIT_LIST_HEAD(&kvm->arch.oos_global_pages); INIT_LIST_HEAD(&kvm->arch.assigned_dev_head); /* Reserve bit 0 of irq_sources_bitmap for userspace irq source */ -- 1.8.2.3