From a1f4d39500ad8ed61825eff061debff42386ab5b Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Mon, 21 Jun 2010 11:44:20 +0300 Subject: [PATCH] KVM: Remove memory alias support As advertised in feature-removal-schedule.txt. Equivalent support is provided by overlapping memory regions. Signed-off-by: Avi Kivity --- Documentation/feature-removal-schedule.txt | 11 -- Documentation/kvm/api.txt | 12 +- arch/ia64/kvm/kvm-ia64.c | 5 - arch/powerpc/kvm/powerpc.c | 5 - arch/s390/kvm/kvm-s390.c | 5 - arch/x86/include/asm/kvm_host.h | 21 ---- arch/x86/kvm/mmu.c | 17 +-- arch/x86/kvm/paging_tmpl.h | 3 +- arch/x86/kvm/x86.c | 125 --------------------- arch/x86/kvm/x86.h | 7 -- include/linux/kvm.h | 1 + include/linux/kvm_host.h | 6 - virt/kvm/kvm_main.c | 18 +-- 13 files changed, 11 insertions(+), 225 deletions(-) diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 1571c0c83dba..ad1e90dd2780 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -538,17 +538,6 @@ Who: Jan Kiszka ---------------------------- -What: KVM memory aliases support -When: July 2010 -Why: Memory aliasing support is used for speeding up guest vga access - through the vga windows. - - Modern userspace no longer uses this feature, so it's just bitrotted - code and can be removed with no impact. -Who: Avi Kivity - ----------------------------- - What: xtime, wall_to_monotonic When: 2.6.36+ Files: kernel/time/timekeeping.c include/linux/time.h diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt index ffba03f55bdf..7e415943a11e 100644 --- a/Documentation/kvm/api.txt +++ b/Documentation/kvm/api.txt @@ -226,17 +226,7 @@ Type: vm ioctl Parameters: struct kvm_memory_alias (in) Returns: 0 (success), -1 (error) -struct kvm_memory_alias { - __u32 slot; /* this has a different namespace than memory slots */ - __u32 flags; - __u64 guest_phys_addr; - __u64 memory_size; - __u64 target_phys_addr; -}; - -Defines a guest physical address space region as an alias to another -region. Useful for aliased address, for example the VGA low memory -window. Should not be used with userspace memory. +This ioctl is obsolete and has been removed. 4.9 KVM_RUN diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 91760e80e268..bd510beb43af 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -1946,11 +1946,6 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) return vcpu->arch.timer_fired; } -gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) -{ - return gfn; -} - int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) { return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE) || diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index b5ebdfbed20b..72a4ad86ee91 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -36,11 +36,6 @@ #define CREATE_TRACE_POINTS #include "trace.h" -gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) -{ - return gfn; -} - int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) { return !(v->arch.msr & MSR_WE) || !!(v->arch.pending_exceptions); diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 08a3b35d30be..4fe68650535c 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -723,11 +723,6 @@ void kvm_arch_flush_shadow(struct kvm *kvm) { } -gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) -{ - return gfn; -} - static int __init kvm_s390_init(void) { int ret; diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 2ec2e27a403e..a57cdeacc4d2 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -69,8 +69,6 @@ #define IOPL_SHIFT 12 -#define KVM_ALIAS_SLOTS 4 - #define KVM_PERMILLE_MMU_PAGES 20 #define KVM_MIN_ALLOC_MMU_PAGES 64 #define KVM_MMU_HASH_SHIFT 10 @@ -362,24 +360,7 @@ struct kvm_vcpu_arch { u64 hv_vapic; }; -struct kvm_mem_alias { - gfn_t base_gfn; - unsigned long npages; - gfn_t target_gfn; -#define KVM_ALIAS_INVALID 1UL - unsigned long flags; -}; - -#define KVM_ARCH_HAS_UNALIAS_INSTANTIATION - -struct kvm_mem_aliases { - struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS]; - int naliases; -}; - struct kvm_arch { - struct kvm_mem_aliases *aliases; - unsigned int n_free_mmu_pages; unsigned int n_requested_mmu_pages; unsigned int n_alloc_mmu_pages; @@ -655,8 +636,6 @@ void kvm_disable_tdp(void); int complete_pio(struct kvm_vcpu *vcpu); bool kvm_check_iopl(struct kvm_vcpu *vcpu); -struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn); - static inline struct kvm_mmu_page *page_header(hpa_t shadow_page) { struct page *page = pfn_to_page(shadow_page >> PAGE_SHIFT); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 8c2f580956d9..c5501bc10106 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -434,9 +434,7 @@ static void account_shadowed(struct kvm *kvm, gfn_t gfn) int *write_count; int i; - gfn = unalias_gfn(kvm, gfn); - - slot = gfn_to_memslot_unaliased(kvm, gfn); + slot = gfn_to_memslot(kvm, gfn); for (i = PT_DIRECTORY_LEVEL; i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) { write_count = slot_largepage_idx(gfn, slot, i); @@ -450,8 +448,7 @@ static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn) int *write_count; int i; - gfn = unalias_gfn(kvm, gfn); - slot = gfn_to_memslot_unaliased(kvm, gfn); + slot = gfn_to_memslot(kvm, gfn); for (i = PT_DIRECTORY_LEVEL; i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) { write_count = slot_largepage_idx(gfn, slot, i); @@ -467,8 +464,7 @@ static int has_wrprotected_page(struct kvm *kvm, struct kvm_memory_slot *slot; int *largepage_idx; - gfn = unalias_gfn(kvm, gfn); - slot = gfn_to_memslot_unaliased(kvm, gfn); + slot = gfn_to_memslot(kvm, gfn); if (slot) { largepage_idx = slot_largepage_idx(gfn, slot, level); return *largepage_idx; @@ -521,7 +517,6 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn) /* * Take gfn and return the reverse mapping to it. - * Note: gfn must be unaliased before this function get called */ static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int level) @@ -561,7 +556,6 @@ static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) if (!is_rmap_spte(*spte)) return count; - gfn = unalias_gfn(vcpu->kvm, gfn); sp = page_header(__pa(spte)); kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn); rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level); @@ -698,7 +692,6 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn) u64 *spte; int i, write_protected = 0; - gfn = unalias_gfn(kvm, gfn); rmapp = gfn_to_rmap(kvm, gfn, PT_PAGE_TABLE_LEVEL); spte = rmap_next(kvm, rmapp, NULL); @@ -885,7 +878,6 @@ static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) sp = page_header(__pa(spte)); - gfn = unalias_gfn(vcpu->kvm, gfn); rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level); kvm_unmap_rmapp(vcpu->kvm, rmapp, 0); @@ -3510,8 +3502,7 @@ static void audit_write_protection(struct kvm_vcpu *vcpu) if (sp->unsync) continue; - gfn = unalias_gfn(vcpu->kvm, sp->gfn); - slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn); + slot = gfn_to_memslot(vcpu->kvm, sp->gfn); rmapp = &slot->rmap[gfn - slot->base_gfn]; spte = rmap_next(vcpu->kvm, rmapp, NULL); diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 863920f649fb..a21a86ef9e20 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -576,7 +576,6 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu, * 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 * can't change unless all sptes pointing to it are nuked first. - * - Alias changes zap the entire shadow cache. */ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, bool clear_unsync) @@ -611,7 +610,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, return -EINVAL; gfn = gpte_to_gfn(gpte); - if (unalias_gfn(vcpu->kvm, gfn) != sp->gfns[i] || + if (gfn != sp->gfns[i] || !is_present_gpte(gpte) || !(gpte & PT_ACCESSED_MASK)) { u64 nonpresent; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8e60b6c9c0b0..62596d373a49 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2740,115 +2740,6 @@ static int kvm_vm_ioctl_get_nr_mmu_pages(struct kvm *kvm) return kvm->arch.n_alloc_mmu_pages; } -gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn) -{ - int i; - struct kvm_mem_alias *alias; - struct kvm_mem_aliases *aliases; - - aliases = kvm_aliases(kvm); - - for (i = 0; i < aliases->naliases; ++i) { - alias = &aliases->aliases[i]; - if (alias->flags & KVM_ALIAS_INVALID) - continue; - if (gfn >= alias->base_gfn - && gfn < alias->base_gfn + alias->npages) - return alias->target_gfn + gfn - alias->base_gfn; - } - return gfn; -} - -gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) -{ - int i; - struct kvm_mem_alias *alias; - struct kvm_mem_aliases *aliases; - - aliases = kvm_aliases(kvm); - - for (i = 0; i < aliases->naliases; ++i) { - alias = &aliases->aliases[i]; - if (gfn >= alias->base_gfn - && gfn < alias->base_gfn + alias->npages) - return alias->target_gfn + gfn - alias->base_gfn; - } - return gfn; -} - -/* - * Set a new alias region. Aliases map a portion of physical memory into - * another portion. This is useful for memory windows, for example the PC - * VGA region. - */ -static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm, - struct kvm_memory_alias *alias) -{ - int r, n; - struct kvm_mem_alias *p; - struct kvm_mem_aliases *aliases, *old_aliases; - - r = -EINVAL; - /* General sanity checks */ - if (alias->memory_size & (PAGE_SIZE - 1)) - goto out; - if (alias->guest_phys_addr & (PAGE_SIZE - 1)) - goto out; - if (alias->slot >= KVM_ALIAS_SLOTS) - goto out; - if (alias->guest_phys_addr + alias->memory_size - < alias->guest_phys_addr) - goto out; - if (alias->target_phys_addr + alias->memory_size - < alias->target_phys_addr) - goto out; - - r = -ENOMEM; - aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL); - if (!aliases) - goto out; - - mutex_lock(&kvm->slots_lock); - - /* invalidate any gfn reference in case of deletion/shrinking */ - memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases)); - aliases->aliases[alias->slot].flags |= KVM_ALIAS_INVALID; - old_aliases = kvm->arch.aliases; - rcu_assign_pointer(kvm->arch.aliases, aliases); - synchronize_srcu_expedited(&kvm->srcu); - kvm_mmu_zap_all(kvm); - kfree(old_aliases); - - r = -ENOMEM; - aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL); - if (!aliases) - goto out_unlock; - - memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases)); - - p = &aliases->aliases[alias->slot]; - p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT; - p->npages = alias->memory_size >> PAGE_SHIFT; - p->target_gfn = alias->target_phys_addr >> PAGE_SHIFT; - p->flags &= ~(KVM_ALIAS_INVALID); - - for (n = KVM_ALIAS_SLOTS; n > 0; --n) - if (aliases->aliases[n - 1].npages) - break; - aliases->naliases = n; - - old_aliases = kvm->arch.aliases; - rcu_assign_pointer(kvm->arch.aliases, aliases); - synchronize_srcu_expedited(&kvm->srcu); - kfree(old_aliases); - r = 0; - -out_unlock: - mutex_unlock(&kvm->slots_lock); -out: - return r; -} - static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip) { int r; @@ -3056,7 +2947,6 @@ long kvm_arch_vm_ioctl(struct file *filp, union { struct kvm_pit_state ps; struct kvm_pit_state2 ps2; - struct kvm_memory_alias alias; struct kvm_pit_config pit_config; } u; @@ -3101,14 +2991,6 @@ long kvm_arch_vm_ioctl(struct file *filp, case KVM_GET_NR_MMU_PAGES: r = kvm_vm_ioctl_get_nr_mmu_pages(kvm); break; - case KVM_SET_MEMORY_ALIAS: - r = -EFAULT; - if (copy_from_user(&u.alias, argp, sizeof(struct kvm_memory_alias))) - goto out; - r = kvm_vm_ioctl_set_memory_alias(kvm, &u.alias); - if (r) - goto out; - break; case KVM_CREATE_IRQCHIP: { struct kvm_pic *vpic; @@ -5559,12 +5441,6 @@ struct kvm *kvm_arch_create_vm(void) if (!kvm) return ERR_PTR(-ENOMEM); - kvm->arch.aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL); - if (!kvm->arch.aliases) { - kfree(kvm); - return ERR_PTR(-ENOMEM); - } - INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); INIT_LIST_HEAD(&kvm->arch.assigned_dev_head); @@ -5622,7 +5498,6 @@ void kvm_arch_destroy_vm(struct kvm *kvm) if (kvm->arch.ept_identity_pagetable) put_page(kvm->arch.ept_identity_pagetable); cleanup_srcu_struct(&kvm->srcu); - kfree(kvm->arch.aliases); kfree(kvm); } diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index f4b54458285b..b7a404722d2b 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -65,13 +65,6 @@ static inline int is_paging(struct kvm_vcpu *vcpu) return kvm_read_cr0_bits(vcpu, X86_CR0_PG); } -static inline struct kvm_mem_aliases *kvm_aliases(struct kvm *kvm) -{ - return rcu_dereference_check(kvm->arch.aliases, - srcu_read_lock_held(&kvm->srcu) - || lockdep_is_held(&kvm->slots_lock)); -} - void kvm_before_handle_nmi(struct kvm_vcpu *vcpu); void kvm_after_handle_nmi(struct kvm_vcpu *vcpu); diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 6fd40f540a8e..636fc381c897 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -619,6 +619,7 @@ struct kvm_clock_data { */ #define KVM_CREATE_VCPU _IO(KVMIO, 0x41) #define KVM_GET_DIRTY_LOG _IOW(KVMIO, 0x42, struct kvm_dirty_log) +/* KVM_SET_MEMORY_ALIAS is obsolete: */ #define KVM_SET_MEMORY_ALIAS _IOW(KVMIO, 0x43, struct kvm_memory_alias) #define KVM_SET_NR_MMU_PAGES _IO(KVMIO, 0x44) #define KVM_GET_NR_MMU_PAGES _IO(KVMIO, 0x45) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2d96555cd4ed..240e460777bc 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -286,8 +286,6 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, int user_alloc); void kvm_disable_largepages(void); void kvm_arch_flush_shadow(struct kvm *kvm); -gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn); -gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn); struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn); @@ -564,10 +562,6 @@ static inline int mmu_notifier_retry(struct kvm_vcpu *vcpu, unsigned long mmu_se } #endif -#ifndef KVM_ARCH_HAS_UNALIAS_INSTANTIATION -#define unalias_gfn_instantiation unalias_gfn -#endif - #ifdef CONFIG_HAVE_KVM_IRQCHIP #define KVM_MAX_IRQ_ROUTES 1024 diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 84a090644d9d..65417e3d8462 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -841,7 +841,7 @@ int kvm_is_error_hva(unsigned long addr) } EXPORT_SYMBOL_GPL(kvm_is_error_hva); -struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn) +struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) { int i; struct kvm_memslots *slots = kvm_memslots(kvm); @@ -855,20 +855,13 @@ struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn) } return NULL; } -EXPORT_SYMBOL_GPL(gfn_to_memslot_unaliased); - -struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) -{ - gfn = unalias_gfn(kvm, gfn); - return gfn_to_memslot_unaliased(kvm, gfn); -} +EXPORT_SYMBOL_GPL(gfn_to_memslot); int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { int i; struct kvm_memslots *slots = kvm_memslots(kvm); - gfn = unalias_gfn_instantiation(kvm, gfn); for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { struct kvm_memory_slot *memslot = &slots->memslots[i]; @@ -913,7 +906,6 @@ int memslot_id(struct kvm *kvm, gfn_t gfn) struct kvm_memslots *slots = kvm_memslots(kvm); struct kvm_memory_slot *memslot = NULL; - gfn = unalias_gfn(kvm, gfn); for (i = 0; i < slots->nmemslots; ++i) { memslot = &slots->memslots[i]; @@ -934,8 +926,7 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *slot; - gfn = unalias_gfn_instantiation(kvm, gfn); - slot = gfn_to_memslot_unaliased(kvm, gfn); + slot = gfn_to_memslot(kvm, gfn); if (!slot || slot->flags & KVM_MEMSLOT_INVALID) return bad_hva(); return gfn_to_hva_memslot(slot, gfn); @@ -1202,8 +1193,7 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *memslot; - gfn = unalias_gfn(kvm, gfn); - memslot = gfn_to_memslot_unaliased(kvm, gfn); + memslot = gfn_to_memslot(kvm, gfn); if (memslot && memslot->dirty_bitmap) { unsigned long rel_gfn = gfn - memslot->base_gfn; -- 2.30.2