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Diffstat (limited to 'drivers/kvm/mmu.c')
-rw-r--r--drivers/kvm/mmu.c89
1 files changed, 68 insertions, 21 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index feb5ac986c5d..069ce83f018e 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -156,6 +156,16 @@ static struct kmem_cache *pte_chain_cache;
static struct kmem_cache *rmap_desc_cache;
static struct kmem_cache *mmu_page_header_cache;
+static u64 __read_mostly shadow_trap_nonpresent_pte;
+static u64 __read_mostly shadow_notrap_nonpresent_pte;
+
+void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
+{
+ shadow_trap_nonpresent_pte = trap_pte;
+ shadow_notrap_nonpresent_pte = notrap_pte;
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
+
static int is_write_protection(struct kvm_vcpu *vcpu)
{
return vcpu->cr0 & X86_CR0_WP;
@@ -176,6 +186,13 @@ static int is_present_pte(unsigned long pte)
return pte & PT_PRESENT_MASK;
}
+static int is_shadow_present_pte(u64 pte)
+{
+ pte &= ~PT_SHADOW_IO_MARK;
+ return pte != shadow_trap_nonpresent_pte
+ && pte != shadow_notrap_nonpresent_pte;
+}
+
static int is_writeble_pte(unsigned long pte)
{
return pte & PT_WRITABLE_MASK;
@@ -450,7 +467,7 @@ static int is_empty_shadow_page(u64 *spt)
u64 *end;
for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
- if (*pos != 0) {
+ if ((*pos & ~PT_SHADOW_IO_MARK) != shadow_trap_nonpresent_pte) {
printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
pos, *pos);
return 0;
@@ -632,6 +649,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
page->gfn = gfn;
page->role = role;
hlist_add_head(&page->hash_link, bucket);
+ vcpu->mmu.prefetch_page(vcpu, page);
if (!metaphysical)
rmap_write_protect(vcpu, gfn);
return page;
@@ -648,9 +666,9 @@ static void kvm_mmu_page_unlink_children(struct kvm *kvm,
if (page->role.level == PT_PAGE_TABLE_LEVEL) {
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
- if (pt[i] & PT_PRESENT_MASK)
+ if (is_shadow_present_pte(pt[i]))
rmap_remove(&pt[i]);
- pt[i] = 0;
+ pt[i] = shadow_trap_nonpresent_pte;
}
kvm_flush_remote_tlbs(kvm);
return;
@@ -659,8 +677,8 @@ static void kvm_mmu_page_unlink_children(struct kvm *kvm,
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
ent = pt[i];
- pt[i] = 0;
- if (!(ent & PT_PRESENT_MASK))
+ pt[i] = shadow_trap_nonpresent_pte;
+ if (!is_shadow_present_pte(ent))
continue;
ent &= PT64_BASE_ADDR_MASK;
mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
@@ -691,7 +709,7 @@ static void kvm_mmu_zap_page(struct kvm *kvm,
}
BUG_ON(!parent_pte);
kvm_mmu_put_page(page, parent_pte);
- set_shadow_pte(parent_pte, 0);
+ set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
}
kvm_mmu_page_unlink_children(kvm, page);
if (!page->root_count) {
@@ -798,7 +816,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
if (level == 1) {
pte = table[index];
- if (is_present_pte(pte) && is_writeble_pte(pte))
+ if (is_shadow_present_pte(pte) && is_writeble_pte(pte))
return 0;
mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
page_header_update_slot(vcpu->kvm, table, v);
@@ -808,7 +826,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
return 0;
}
- if (table[index] == 0) {
+ if (table[index] == shadow_trap_nonpresent_pte) {
struct kvm_mmu_page *new_table;
gfn_t pseudo_gfn;
@@ -829,6 +847,15 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
}
}
+static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
+ struct kvm_mmu_page *sp)
+{
+ int i;
+
+ for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
+ sp->spt[i] = shadow_trap_nonpresent_pte;
+}
+
static void mmu_free_roots(struct kvm_vcpu *vcpu)
{
int i;
@@ -943,6 +970,7 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu)
context->page_fault = nonpaging_page_fault;
context->gva_to_gpa = nonpaging_gva_to_gpa;
context->free = nonpaging_free;
+ context->prefetch_page = nonpaging_prefetch_page;
context->root_level = 0;
context->shadow_root_level = PT32E_ROOT_LEVEL;
context->root_hpa = INVALID_PAGE;
@@ -989,6 +1017,7 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
context->new_cr3 = paging_new_cr3;
context->page_fault = paging64_page_fault;
context->gva_to_gpa = paging64_gva_to_gpa;
+ context->prefetch_page = paging64_prefetch_page;
context->free = paging_free;
context->root_level = level;
context->shadow_root_level = level;
@@ -1009,6 +1038,7 @@ static int paging32_init_context(struct kvm_vcpu *vcpu)
context->page_fault = paging32_page_fault;
context->gva_to_gpa = paging32_gva_to_gpa;
context->free = paging_free;
+ context->prefetch_page = paging32_prefetch_page;
context->root_level = PT32_ROOT_LEVEL;
context->shadow_root_level = PT32E_ROOT_LEVEL;
context->root_hpa = INVALID_PAGE;
@@ -1081,7 +1111,7 @@ static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *child;
pte = *spte;
- if (is_present_pte(pte)) {
+ if (is_shadow_present_pte(pte)) {
if (page->role.level == PT_PAGE_TABLE_LEVEL)
rmap_remove(spte);
else {
@@ -1089,22 +1119,25 @@ static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
mmu_page_remove_parent_pte(child, spte);
}
}
- set_shadow_pte(spte, 0);
+ set_shadow_pte(spte, shadow_trap_nonpresent_pte);
kvm_flush_remote_tlbs(vcpu->kvm);
}
static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *page,
u64 *spte,
- const void *new, int bytes)
+ const void *new, int bytes,
+ int offset_in_pte)
{
if (page->role.level != PT_PAGE_TABLE_LEVEL)
return;
if (page->role.glevels == PT32_ROOT_LEVEL)
- paging32_update_pte(vcpu, page, spte, new, bytes);
+ paging32_update_pte(vcpu, page, spte, new, bytes,
+ offset_in_pte);
else
- paging64_update_pte(vcpu, page, spte, new, bytes);
+ paging64_update_pte(vcpu, page, spte, new, bytes,
+ offset_in_pte);
}
void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
@@ -1126,6 +1159,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
int npte;
pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
+ kvm_mmu_audit(vcpu, "pre pte write");
if (gfn == vcpu->last_pt_write_gfn) {
++vcpu->last_pt_write_count;
if (vcpu->last_pt_write_count >= 3)
@@ -1181,10 +1215,12 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
spte = &page->spt[page_offset / sizeof(*spte)];
while (npte--) {
mmu_pte_write_zap_pte(vcpu, page, spte);
- mmu_pte_write_new_pte(vcpu, page, spte, new, bytes);
+ mmu_pte_write_new_pte(vcpu, page, spte, new, bytes,
+ page_offset & (pte_size - 1));
++spte;
}
}
+ kvm_mmu_audit(vcpu, "post pte write");
}
int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
@@ -1359,22 +1395,33 @@ static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
u64 ent = pt[i];
- if (!(ent & PT_PRESENT_MASK))
+ if (ent == shadow_trap_nonpresent_pte)
continue;
va = canonicalize(va);
- if (level > 1)
+ if (level > 1) {
+ if (ent == shadow_notrap_nonpresent_pte)
+ printk(KERN_ERR "audit: (%s) nontrapping pte"
+ " in nonleaf level: levels %d gva %lx"
+ " level %d pte %llx\n", audit_msg,
+ vcpu->mmu.root_level, va, level, ent);
+
audit_mappings_page(vcpu, ent, va, level - 1);
- else {
+ } else {
gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, va);
hpa_t hpa = gpa_to_hpa(vcpu, gpa);
- if ((ent & PT_PRESENT_MASK)
+ if (is_shadow_present_pte(ent)
&& (ent & PT64_BASE_ADDR_MASK) != hpa)
- printk(KERN_ERR "audit error: (%s) levels %d"
- " gva %lx gpa %llx hpa %llx ent %llx\n",
+ printk(KERN_ERR "xx audit error: (%s) levels %d"
+ " gva %lx gpa %llx hpa %llx ent %llx %d\n",
audit_msg, vcpu->mmu.root_level,
- va, gpa, hpa, ent);
+ va, gpa, hpa, ent, is_shadow_present_pte(ent));
+ else if (ent == shadow_notrap_nonpresent_pte
+ && !is_error_hpa(hpa))
+ printk(KERN_ERR "audit: (%s) notrap shadow,"
+ " valid guest gva %lx\n", audit_msg, va);
+
}
}
}