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authorXiao Guangrong <xiaoguangrong@cn.fujitsu.com>2010-08-30 14:24:10 +0400
committerAvi Kivity <avi@redhat.com>2010-10-24 12:51:57 +0400
commit2f4f337248cd5660040b7e09b7287a7a0a861f3f (patch)
tree262aac82066af397975f7680707965cf4a2ce969 /arch/x86/kvm/mmu_audit.c
parent8b1fe17cc7a8b2c62b400dcbfaebd96da6b4f58e (diff)
downloadlinux-2f4f337248cd5660040b7e09b7287a7a0a861f3f.tar.xz
KVM: MMU: move audit to a separate file
Move the audit code from arch/x86/kvm/mmu.c to arch/x86/kvm/mmu_audit.c Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu_audit.c')
-rw-r--r--arch/x86/kvm/mmu_audit.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c
new file mode 100644
index 000000000000..fb8a461333c5
--- /dev/null
+++ b/arch/x86/kvm/mmu_audit.c
@@ -0,0 +1,297 @@
+/*
+ * mmu_audit.c:
+ *
+ * Audit code for KVM MMU
+ *
+ * Copyright (C) 2006 Qumranet, Inc.
+ * Copyright 2010 Red Hat, Inc. and/or its affilates.
+ *
+ * Authors:
+ * Yaniv Kamay <yaniv@qumranet.com>
+ * Avi Kivity <avi@qumranet.com>
+ * Marcelo Tosatti <mtosatti@redhat.com>
+ * Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+static const char *audit_msg;
+
+typedef void (*inspect_spte_fn) (struct kvm *kvm, u64 *sptep);
+
+static void __mmu_spte_walk(struct kvm *kvm, struct kvm_mmu_page *sp,
+ inspect_spte_fn fn)
+{
+ int i;
+
+ for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
+ u64 ent = sp->spt[i];
+
+ if (is_shadow_present_pte(ent)) {
+ if (!is_last_spte(ent, sp->role.level)) {
+ struct kvm_mmu_page *child;
+ child = page_header(ent & PT64_BASE_ADDR_MASK);
+ __mmu_spte_walk(kvm, child, fn);
+ } else
+ fn(kvm, &sp->spt[i]);
+ }
+ }
+}
+
+static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
+{
+ int i;
+ struct kvm_mmu_page *sp;
+
+ if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
+ return;
+ if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
+ hpa_t root = vcpu->arch.mmu.root_hpa;
+ sp = page_header(root);
+ __mmu_spte_walk(vcpu->kvm, sp, fn);
+ return;
+ }
+ for (i = 0; i < 4; ++i) {
+ hpa_t root = vcpu->arch.mmu.pae_root[i];
+
+ if (root && VALID_PAGE(root)) {
+ root &= PT64_BASE_ADDR_MASK;
+ sp = page_header(root);
+ __mmu_spte_walk(vcpu->kvm, sp, fn);
+ }
+ }
+ return;
+}
+
+static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
+ gva_t va, int level)
+{
+ u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
+ int i;
+ gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
+
+ for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
+ u64 *sptep = pt + i;
+ struct kvm_mmu_page *sp;
+ gfn_t gfn;
+ pfn_t pfn;
+ hpa_t hpa;
+
+ sp = page_header(__pa(sptep));
+
+ if (sp->unsync) {
+ if (level != PT_PAGE_TABLE_LEVEL) {
+ printk(KERN_ERR "audit: (%s) error: unsync sp: %p level = %d\n",
+ audit_msg, sp, level);
+ return;
+ }
+
+ if (*sptep == shadow_notrap_nonpresent_pte) {
+ printk(KERN_ERR "audit: (%s) error: notrap spte in unsync sp: %p\n",
+ audit_msg, sp);
+ return;
+ }
+ }
+
+ if (sp->role.direct && *sptep == shadow_notrap_nonpresent_pte) {
+ printk(KERN_ERR "audit: (%s) error: notrap spte in direct sp: %p\n",
+ audit_msg, sp);
+ return;
+ }
+
+ if (!is_shadow_present_pte(*sptep) ||
+ !is_last_spte(*sptep, level))
+ return;
+
+ gfn = kvm_mmu_page_get_gfn(sp, sptep - sp->spt);
+ pfn = gfn_to_pfn_atomic(vcpu->kvm, gfn);
+
+ if (is_error_pfn(pfn)) {
+ kvm_release_pfn_clean(pfn);
+ return;
+ }
+
+ hpa = pfn << PAGE_SHIFT;
+
+ if ((*sptep & PT64_BASE_ADDR_MASK) != hpa)
+ printk(KERN_ERR "xx audit error: (%s) levels %d"
+ " gva %lx pfn %llx hpa %llx ent %llxn",
+ audit_msg, vcpu->arch.mmu.root_level,
+ va, pfn, hpa, *sptep);
+ }
+}
+
+static void audit_mappings(struct kvm_vcpu *vcpu)
+{
+ unsigned i;
+
+ if (vcpu->arch.mmu.root_level == 4)
+ audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
+ else
+ for (i = 0; i < 4; ++i)
+ if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
+ audit_mappings_page(vcpu,
+ vcpu->arch.mmu.pae_root[i],
+ i << 30,
+ 2);
+}
+
+void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
+{
+ unsigned long *rmapp;
+ struct kvm_mmu_page *rev_sp;
+ gfn_t gfn;
+
+
+ rev_sp = page_header(__pa(sptep));
+ gfn = kvm_mmu_page_get_gfn(rev_sp, sptep - rev_sp->spt);
+
+ if (!gfn_to_memslot(kvm, gfn)) {
+ if (!printk_ratelimit())
+ return;
+ printk(KERN_ERR "%s: no memslot for gfn %llx\n",
+ audit_msg, gfn);
+ printk(KERN_ERR "%s: index %ld of sp (gfn=%llx)\n",
+ audit_msg, (long int)(sptep - rev_sp->spt),
+ rev_sp->gfn);
+ dump_stack();
+ return;
+ }
+
+ rmapp = gfn_to_rmap(kvm, gfn, rev_sp->role.level);
+ if (!*rmapp) {
+ if (!printk_ratelimit())
+ return;
+ printk(KERN_ERR "%s: no rmap for writable spte %llx\n",
+ audit_msg, *sptep);
+ dump_stack();
+ }
+}
+
+void audit_sptes_have_rmaps(struct kvm_vcpu *vcpu)
+{
+ mmu_spte_walk(vcpu, inspect_spte_has_rmap);
+}
+
+static void check_mappings_rmap(struct kvm_vcpu *vcpu)
+{
+ struct kvm_mmu_page *sp;
+ int i;
+
+ list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
+ u64 *pt = sp->spt;
+
+ if (sp->role.level != PT_PAGE_TABLE_LEVEL)
+ continue;
+
+ for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
+ if (!is_rmap_spte(pt[i]))
+ continue;
+
+ inspect_spte_has_rmap(vcpu->kvm, &pt[i]);
+ }
+ }
+ return;
+}
+
+static void audit_rmap(struct kvm_vcpu *vcpu)
+{
+ check_mappings_rmap(vcpu);
+}
+
+static void audit_write_protection(struct kvm_vcpu *vcpu)
+{
+ struct kvm_mmu_page *sp;
+ struct kvm_memory_slot *slot;
+ unsigned long *rmapp;
+ u64 *spte;
+
+ list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
+ if (sp->role.direct)
+ continue;
+ if (sp->unsync)
+ continue;
+ if (sp->role.invalid)
+ continue;
+
+ slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
+ rmapp = &slot->rmap[sp->gfn - slot->base_gfn];
+
+ spte = rmap_next(vcpu->kvm, rmapp, NULL);
+ while (spte) {
+ if (is_writable_pte(*spte))
+ printk(KERN_ERR "%s: (%s) shadow page has "
+ "writable mappings: gfn %llx role %x\n",
+ __func__, audit_msg, sp->gfn,
+ sp->role.word);
+ spte = rmap_next(vcpu->kvm, rmapp, spte);
+ }
+ }
+}
+
+static void kvm_mmu_audit(void *ignore, struct kvm_vcpu *vcpu, int audit_point)
+{
+ audit_msg = audit_point_name[audit_point];
+ audit_rmap(vcpu);
+ audit_write_protection(vcpu);
+ if (strcmp("pre pte write", audit_msg) != 0)
+ audit_mappings(vcpu);
+ audit_sptes_have_rmaps(vcpu);
+}
+
+static bool mmu_audit;
+
+static void mmu_audit_enable(void)
+{
+ int ret;
+
+ if (mmu_audit)
+ return;
+
+ ret = register_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);
+ WARN_ON(ret);
+
+ mmu_audit = true;
+}
+
+static void mmu_audit_disable(void)
+{
+ if (!mmu_audit)
+ return;
+
+ unregister_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);
+ tracepoint_synchronize_unregister();
+ mmu_audit = false;
+}
+
+static int mmu_audit_set(const char *val, const struct kernel_param *kp)
+{
+ int ret;
+ unsigned long enable;
+
+ ret = strict_strtoul(val, 10, &enable);
+ if (ret < 0)
+ return -EINVAL;
+
+ switch (enable) {
+ case 0:
+ mmu_audit_disable();
+ break;
+ case 1:
+ mmu_audit_enable();
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static struct kernel_param_ops audit_param_ops = {
+ .set = mmu_audit_set,
+ .get = param_get_bool,
+};
+
+module_param_cb(mmu_audit, &audit_param_ops, &mmu_audit, 0644);