[PATCH 2/5] KVM: MMU: check rmap for every spte

Xiao Guangrong
2010-08-28T11:20:47Z

The read-only spte also has reverse mapping, so fix the code to check them,
also modify the function name to fit its doing

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/kvm/mmu.c | 57 +++++++++++++++++++++++----------------------------
1 files changed, 26 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 59bf1d9..1c784b9 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3644,40 +3644,38 @@ void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
struct kvm_mmu_page *rev_sp;
gfn_t gfn;

- if (is_writable_pte(*sptep)) {
- 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;
- }
+ rev_sp = page_header(__pa(sptep));
+ gfn = kvm_mmu_page_get_gfn(rev_sp, sptep - rev_sp->spt);

- 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();
- }
+ 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_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu)
+void audit_sptes_have_rmaps(struct kvm_vcpu *vcpu)
{
mmu_spte_walk(vcpu, inspect_spte_has_rmap);
}

-static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu)
+static void check_mappings_rmap(struct kvm_vcpu *vcpu)
{
struct kvm_mmu_page *sp;
int i;
@@ -3689,12 +3687,9 @@ static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu)
continue;

for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
- u64 ent = pt[i];
-
- if (!(ent & PT_PRESENT_MASK))
- continue;
- if (!is_writable_pte(ent))
+ if (!is_rmap_spte(pt[i]))
continue;
+
inspect_spte_has_rmap(vcpu->kvm, &pt[i]);
}
}
@@ -3703,7 +3698,7 @@ static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu)

static void audit_rmap(struct kvm_vcpu *vcpu)
{
- check_writable_mappings_rmap(vcpu);
+ check_mappings_rmap(vcpu);
count_rmaps(vcpu);
}

@@ -3746,7 +3741,7 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
audit_write_protection(vcpu);
if (strcmp("pre pte write", audit_msg) != 0)
audit_mappings(vcpu);
- audit_writable_sptes_have_rmaps(vcpu);
+ audit_sptes_have_rmaps(vcpu);
dbg = olddbg;
}

--
1.7.0.4