From 6cffe8ca4a2adf1ac5003d9cad08fe4434d6eee0 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Mon, 1 Dec 2008 22:32:04 -0200 Subject: [PATCH] KVM: MMU: skip global pgtables on sync due to cr3 switch Skip syncing global pages on cr3 switch (but not on cr4/cr0). This is important for Linux 32-bit guests with PAE, where the kmap page is marked as global. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 6 ++++ arch/x86/kvm/mmu.c | 53 +++++++++++++++++++++++++++++---- arch/x86/kvm/paging_tmpl.h | 10 ++++--- arch/x86/kvm/x86.c | 4 +++ 4 files changed, 63 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 93d0aed3588..65b1ed29569 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -182,6 +182,8 @@ struct kvm_mmu_page { struct list_head link; struct hlist_node hash_link; + struct list_head oos_link; + /* * The following two entries are used to key the shadow page in the * hash table. @@ -200,6 +202,7 @@ 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 */ @@ -356,6 +359,7 @@ struct kvm_arch{ */ struct list_head active_mmu_pages; struct list_head assigned_dev_head; + struct list_head oos_global_pages; struct dmar_domain *intel_iommu_domain; struct kvm_pic *vpic; struct kvm_ioapic *vioapic; @@ -385,6 +389,7 @@ struct kvm_vm_stat { u32 mmu_recycled; u32 mmu_cache_miss; u32 mmu_unsync; + u32 mmu_unsync_global; u32 remote_tlb_flush; u32 lpages; }; @@ -603,6 +608,7 @@ 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 58c35dead32..cbac9e4b156 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -793,9 +793,11 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE); set_page_private(virt_to_page(sp->spt), (unsigned long)sp); list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); + INIT_LIST_HEAD(&sp->oos_link); ASSERT(is_empty_shadow_page(sp->spt)); bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS); sp->multimapped = 0; + sp->global = 1; sp->parent_pte = parent_pte; --vcpu->kvm->arch.n_free_mmu_pages; return sp; @@ -1066,10 +1068,18 @@ 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; } @@ -1615,9 +1625,15 @@ static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) if (s->role.word != sp->role.word) return 1; } - kvm_mmu_mark_parents_unsync(vcpu, 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); + mmu_convert_notrap(sp); return 0; } @@ -1643,12 +1659,21 @@ 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, - gfn_t gfn, pfn_t pfn, bool speculative, + int global, 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 @@ -1717,8 +1742,8 @@ 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, gfn_t gfn, - pfn_t pfn, bool speculative) + int *ptwrite, int largepage, int global, + gfn_t gfn, pfn_t pfn, bool speculative) { int was_rmapped = 0; int was_writeble = is_writeble_pte(*shadow_pte); @@ -1751,7 +1776,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, } } if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault, - dirty, largepage, gfn, pfn, speculative, true)) { + dirty, largepage, global, gfn, pfn, speculative, true)) { if (write_fault) *ptwrite = 1; kvm_x86_ops->tlb_flush(vcpu); @@ -1808,7 +1833,7 @@ static int direct_map_entry(struct kvm_shadow_walk *_walk, || (walk->largepage && level == PT_DIRECTORY_LEVEL)) { mmu_set_spte(vcpu, sptep, ACC_ALL, ACC_ALL, 0, walk->write, 1, &walk->pt_write, - walk->largepage, gfn, walk->pfn, false); + walk->largepage, 0, gfn, walk->pfn, false); ++vcpu->stat.pf_fixed; return 1; } @@ -1995,6 +2020,15 @@ 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); @@ -2002,6 +2036,13 @@ 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 84eee43bbe7..e644d81979b 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -274,7 +274,8 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page, return; kvm_get_pfn(pfn); mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0, - gpte & PT_DIRTY_MASK, NULL, largepage, gpte_to_gfn(gpte), + gpte & PT_DIRTY_MASK, NULL, largepage, + gpte & PT_GLOBAL_MASK, gpte_to_gfn(gpte), pfn, true); } @@ -301,8 +302,9 @@ static int FNAME(shadow_walk_entry)(struct kvm_shadow_walk *_sw, mmu_set_spte(vcpu, sptep, access, gw->pte_access & access, sw->user_fault, sw->write_fault, gw->ptes[gw->level-1] & PT_DIRTY_MASK, - sw->ptwrite, sw->largepage, gw->gfn, sw->pfn, - false); + sw->ptwrite, sw->largepage, + gw->ptes[gw->level-1] & PT_GLOBAL_MASK, + gw->gfn, sw->pfn, false); sw->sptep = sptep; return 1; } @@ -580,7 +582,7 @@ 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, gfn, + is_dirty_pte(gpte), 0, gpte & PT_GLOBAL_MASK, gfn, spte_to_pfn(sp->spt[i]), true, false); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7a2aeba0bfb..774db00d2db 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -104,6 +104,7 @@ 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 } @@ -315,6 +316,7 @@ 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; } @@ -358,6 +360,7 @@ void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) } kvm_x86_ops->set_cr4(vcpu, cr4); vcpu->arch.cr4 = cr4; + kvm_mmu_sync_global(vcpu); kvm_mmu_reset_context(vcpu); } EXPORT_SYMBOL_GPL(kvm_set_cr4); @@ -4113,6 +4116,7 @@ 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 */ -- 2.39.2