MIPS: Yosemite, Emma: Fix off-by-two in arcs_cmdline buffer size check
[linux-2.6/linux-mips.git] / arch / x86 / kvm / mmu_audit.c
blob746ec259d02490bf7b7ce552560ff37e170d9825
1 /*
2 * mmu_audit.c:
4 * Audit code for KVM MMU
6 * Copyright (C) 2006 Qumranet, Inc.
7 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
9 * Authors:
10 * Yaniv Kamay <yaniv@qumranet.com>
11 * Avi Kivity <avi@qumranet.com>
12 * Marcelo Tosatti <mtosatti@redhat.com>
13 * Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
15 * This work is licensed under the terms of the GNU GPL, version 2. See
16 * the COPYING file in the top-level directory.
20 #include <linux/ratelimit.h>
22 #define audit_printk(kvm, fmt, args...) \
23 printk(KERN_ERR "audit: (%s) error: " \
24 fmt, audit_point_name[kvm->arch.audit_point], ##args)
26 typedef void (*inspect_spte_fn) (struct kvm_vcpu *vcpu, u64 *sptep, int level);
28 static void __mmu_spte_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
29 inspect_spte_fn fn, int level)
31 int i;
33 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
34 u64 *ent = sp->spt;
36 fn(vcpu, ent + i, level);
38 if (is_shadow_present_pte(ent[i]) &&
39 !is_last_spte(ent[i], level)) {
40 struct kvm_mmu_page *child;
42 child = page_header(ent[i] & PT64_BASE_ADDR_MASK);
43 __mmu_spte_walk(vcpu, child, fn, level - 1);
48 static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
50 int i;
51 struct kvm_mmu_page *sp;
53 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
54 return;
56 if (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL) {
57 hpa_t root = vcpu->arch.mmu.root_hpa;
59 sp = page_header(root);
60 __mmu_spte_walk(vcpu, sp, fn, PT64_ROOT_LEVEL);
61 return;
64 for (i = 0; i < 4; ++i) {
65 hpa_t root = vcpu->arch.mmu.pae_root[i];
67 if (root && VALID_PAGE(root)) {
68 root &= PT64_BASE_ADDR_MASK;
69 sp = page_header(root);
70 __mmu_spte_walk(vcpu, sp, fn, 2);
74 return;
77 typedef void (*sp_handler) (struct kvm *kvm, struct kvm_mmu_page *sp);
79 static void walk_all_active_sps(struct kvm *kvm, sp_handler fn)
81 struct kvm_mmu_page *sp;
83 list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link)
84 fn(kvm, sp);
87 static void audit_mappings(struct kvm_vcpu *vcpu, u64 *sptep, int level)
89 struct kvm_mmu_page *sp;
90 gfn_t gfn;
91 pfn_t pfn;
92 hpa_t hpa;
94 sp = page_header(__pa(sptep));
96 if (sp->unsync) {
97 if (level != PT_PAGE_TABLE_LEVEL) {
98 audit_printk(vcpu->kvm, "unsync sp: %p "
99 "level = %d\n", sp, level);
100 return;
104 if (!is_shadow_present_pte(*sptep) || !is_last_spte(*sptep, level))
105 return;
107 gfn = kvm_mmu_page_get_gfn(sp, sptep - sp->spt);
108 pfn = gfn_to_pfn_atomic(vcpu->kvm, gfn);
110 if (is_error_pfn(pfn)) {
111 kvm_release_pfn_clean(pfn);
112 return;
115 hpa = pfn << PAGE_SHIFT;
116 if ((*sptep & PT64_BASE_ADDR_MASK) != hpa)
117 audit_printk(vcpu->kvm, "levels %d pfn %llx hpa %llx "
118 "ent %llxn", vcpu->arch.mmu.root_level, pfn,
119 hpa, *sptep);
122 static void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
124 static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
125 unsigned long *rmapp;
126 struct kvm_mmu_page *rev_sp;
127 gfn_t gfn;
129 rev_sp = page_header(__pa(sptep));
130 gfn = kvm_mmu_page_get_gfn(rev_sp, sptep - rev_sp->spt);
132 if (!gfn_to_memslot(kvm, gfn)) {
133 if (!__ratelimit(&ratelimit_state))
134 return;
135 audit_printk(kvm, "no memslot for gfn %llx\n", gfn);
136 audit_printk(kvm, "index %ld of sp (gfn=%llx)\n",
137 (long int)(sptep - rev_sp->spt), rev_sp->gfn);
138 dump_stack();
139 return;
142 rmapp = gfn_to_rmap(kvm, gfn, rev_sp->role.level);
143 if (!*rmapp) {
144 if (!__ratelimit(&ratelimit_state))
145 return;
146 audit_printk(kvm, "no rmap for writable spte %llx\n",
147 *sptep);
148 dump_stack();
152 static void audit_sptes_have_rmaps(struct kvm_vcpu *vcpu, u64 *sptep, int level)
154 if (is_shadow_present_pte(*sptep) && is_last_spte(*sptep, level))
155 inspect_spte_has_rmap(vcpu->kvm, sptep);
158 static void audit_spte_after_sync(struct kvm_vcpu *vcpu, u64 *sptep, int level)
160 struct kvm_mmu_page *sp = page_header(__pa(sptep));
162 if (vcpu->kvm->arch.audit_point == AUDIT_POST_SYNC && sp->unsync)
163 audit_printk(vcpu->kvm, "meet unsync sp(%p) after sync "
164 "root.\n", sp);
167 static void check_mappings_rmap(struct kvm *kvm, struct kvm_mmu_page *sp)
169 int i;
171 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
172 return;
174 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
175 if (!is_rmap_spte(sp->spt[i]))
176 continue;
178 inspect_spte_has_rmap(kvm, sp->spt + i);
182 static void audit_write_protection(struct kvm *kvm, struct kvm_mmu_page *sp)
184 struct kvm_memory_slot *slot;
185 unsigned long *rmapp;
186 u64 *spte;
188 if (sp->role.direct || sp->unsync || sp->role.invalid)
189 return;
191 slot = gfn_to_memslot(kvm, sp->gfn);
192 rmapp = &slot->rmap[sp->gfn - slot->base_gfn];
194 spte = rmap_next(kvm, rmapp, NULL);
195 while (spte) {
196 if (is_writable_pte(*spte))
197 audit_printk(kvm, "shadow page has writable "
198 "mappings: gfn %llx role %x\n",
199 sp->gfn, sp->role.word);
200 spte = rmap_next(kvm, rmapp, spte);
204 static void audit_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
206 check_mappings_rmap(kvm, sp);
207 audit_write_protection(kvm, sp);
210 static void audit_all_active_sps(struct kvm *kvm)
212 walk_all_active_sps(kvm, audit_sp);
215 static void audit_spte(struct kvm_vcpu *vcpu, u64 *sptep, int level)
217 audit_sptes_have_rmaps(vcpu, sptep, level);
218 audit_mappings(vcpu, sptep, level);
219 audit_spte_after_sync(vcpu, sptep, level);
222 static void audit_vcpu_spte(struct kvm_vcpu *vcpu)
224 mmu_spte_walk(vcpu, audit_spte);
227 static void kvm_mmu_audit(void *ignore, struct kvm_vcpu *vcpu, int point)
229 static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
231 if (!__ratelimit(&ratelimit_state))
232 return;
234 vcpu->kvm->arch.audit_point = point;
235 audit_all_active_sps(vcpu->kvm);
236 audit_vcpu_spte(vcpu);
239 static bool mmu_audit;
241 static void mmu_audit_enable(void)
243 int ret;
245 if (mmu_audit)
246 return;
248 ret = register_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);
249 WARN_ON(ret);
251 mmu_audit = true;
254 static void mmu_audit_disable(void)
256 if (!mmu_audit)
257 return;
259 unregister_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);
260 tracepoint_synchronize_unregister();
261 mmu_audit = false;
264 static int mmu_audit_set(const char *val, const struct kernel_param *kp)
266 int ret;
267 unsigned long enable;
269 ret = strict_strtoul(val, 10, &enable);
270 if (ret < 0)
271 return -EINVAL;
273 switch (enable) {
274 case 0:
275 mmu_audit_disable();
276 break;
277 case 1:
278 mmu_audit_enable();
279 break;
280 default:
281 return -EINVAL;
284 return 0;
287 static struct kernel_param_ops audit_param_ops = {
288 .set = mmu_audit_set,
289 .get = param_get_bool,
292 module_param_cb(mmu_audit, &audit_param_ops, &mmu_audit, 0644);