[PATCH 2/4] KVM: MMU: improve active sp audit

Xiao Guangrong
2010-08-28T12:01:30Z

Both audit_rmap() and audit_write_protection() need to walk all active sp, so we can do
these checking in a sp walking

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/kvm/mmu_debug.c | 80 +++++++++++++++++++++++----------------------
1 files changed, 41 insertions(+), 39 deletions(-)

diff --git a/arch/x86/kvm/mmu_debug.c b/arch/x86/kvm/mmu_debug.c
index d2c0048..812d6dc 100644
--- a/arch/x86/kvm/mmu_debug.c
+++ b/arch/x86/kvm/mmu_debug.c
@@ -70,6 +70,16 @@ static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
return;
}

+typedef void (*sp_handler) (struct kvm *kvm, struct kvm_mmu_page *sp);
+
+static void walk_all_active_sps(struct kvm *kvm, sp_handler fn)
+{
+ struct kvm_mmu_page *sp;
+
+ list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link)
+ fn(kvm, sp);
+}
+
static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
gva_t va, int level)
{
@@ -180,67 +190,59 @@ 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)
+static void check_mappings_rmap(struct kvm *kvm, struct kvm_mmu_page *sp)
{
- 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;
+ if (sp->role.level != PT_PAGE_TABLE_LEVEL)
+ return;

- for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
- if (!is_rmap_spte(pt[i]))
- continue;
+ for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
+ if (!is_rmap_spte(sp->spt[i]))
+ return;

- inspect_spte_has_rmap(vcpu->kvm, &pt[i]);
- }
+ inspect_spte_has_rmap(kvm, sp->spt + i);
}
- return;
}

-static void audit_rmap(struct kvm_vcpu *vcpu)
+static void audit_write_protection(struct kvm *kvm, struct kvm_mmu_page *sp)
{
- 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 "
+ if (sp->role.direct || sp->unsync || sp->role.invalid)
+ return;
+
+ slot = gfn_to_memslot(kvm, sp->gfn);
+ rmapp = &slot->rmap[sp->gfn - slot->base_gfn];
+
+ spte = rmap_next(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);
- }
+ spte = rmap_next(kvm, rmapp, spte);
}
}

+static void audit_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+ check_mappings_rmap(kvm, sp);
+ audit_write_protection(kvm, sp);
+}
+
+static void audit_all_active_sps(struct kvm *kvm)
+{
+ walk_all_active_sps(kvm, audit_sp);
+}
+
static void kvm_mmu_audit(void *ignore, struct kvm_vcpu *vcpu, const char *msg)
{
audit_msg = msg;
- audit_rmap(vcpu);
- audit_write_protection(vcpu);
+ audit_all_active_sps(vcpu->kvm);
if (strcmp("pre pte write", audit_msg) != 0)
audit_mappings(vcpu);
audit_sptes_have_rmaps(vcpu);
--
1.7.0.4