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-rw-r--r--drivers/kvm/kvm.h16
-rw-r--r--drivers/kvm/kvm_main.c18
-rw-r--r--drivers/kvm/mmu.c151
-rw-r--r--drivers/kvm/paging_tmpl.h5
4 files changed, 153 insertions, 37 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index b24a86e1f43..91e0c75aca8 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -168,6 +168,17 @@ struct kvm_mmu {
u64 *pae_root;
};
+#define KVM_NR_MEM_OBJS 20
+
+struct kvm_mmu_memory_cache {
+ int nobjs;
+ void *objects[KVM_NR_MEM_OBJS];
+};
+
+/*
+ * We don't want allocation failures within the mmu code, so we preallocate
+ * enough memory for a single page fault in a cache.
+ */
struct kvm_guest_debug {
int enabled;
unsigned long bp[4];
@@ -239,6 +250,9 @@ struct kvm_vcpu {
struct kvm_mmu_page page_header_buf[KVM_NUM_MMU_PAGES];
struct kvm_mmu mmu;
+ struct kvm_mmu_memory_cache mmu_pte_chain_cache;
+ struct kvm_mmu_memory_cache mmu_rmap_desc_cache;
+
gfn_t last_pt_write_gfn;
int last_pt_write_count;
@@ -381,7 +395,7 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu);
int kvm_mmu_setup(struct kvm_vcpu *vcpu);
int kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
-void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot);
+void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot);
hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa);
#define HPA_MSB ((sizeof(hpa_t) * 8) - 1)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 2e6bc565995..6623fecff04 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -702,6 +702,13 @@ out:
return r;
}
+static void do_remove_write_access(struct kvm_vcpu *vcpu, int slot)
+{
+ spin_lock(&vcpu->kvm->lock);
+ kvm_mmu_slot_remove_write_access(vcpu, slot);
+ spin_unlock(&vcpu->kvm->lock);
+}
+
/*
* Get (and clear) the dirty memory log for a memory slot.
*/
@@ -711,6 +718,7 @@ static int kvm_dev_ioctl_get_dirty_log(struct kvm *kvm,
struct kvm_memory_slot *memslot;
int r, i;
int n;
+ int cleared;
unsigned long any = 0;
spin_lock(&kvm->lock);
@@ -741,15 +749,17 @@ static int kvm_dev_ioctl_get_dirty_log(struct kvm *kvm,
if (any) {
- spin_lock(&kvm->lock);
- kvm_mmu_slot_remove_write_access(kvm, log->slot);
- spin_unlock(&kvm->lock);
- memset(memslot->dirty_bitmap, 0, n);
+ cleared = 0;
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
struct kvm_vcpu *vcpu = vcpu_load(kvm, i);
if (!vcpu)
continue;
+ if (!cleared) {
+ do_remove_write_access(vcpu, log->slot);
+ memset(memslot->dirty_bitmap, 0, n);
+ cleared = 1;
+ }
kvm_arch_ops->tlb_flush(vcpu);
vcpu_put(vcpu);
}
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 0bd2a19709c..e96362aa794 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -166,6 +166,84 @@ static int is_rmap_pte(u64 pte)
== (PT_WRITABLE_MASK | PT_PRESENT_MASK);
}
+static void mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
+ size_t objsize, int min)
+{
+ void *obj;
+
+ if (cache->nobjs >= min)
+ return;
+ while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
+ obj = kzalloc(objsize, GFP_NOWAIT);
+ if (!obj)
+ BUG();
+ cache->objects[cache->nobjs++] = obj;
+ }
+}
+
+static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
+{
+ while (mc->nobjs)
+ kfree(mc->objects[--mc->nobjs]);
+}
+
+static void mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
+{
+ mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
+ sizeof(struct kvm_pte_chain), 4);
+ mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
+ sizeof(struct kvm_rmap_desc), 1);
+}
+
+static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
+{
+ mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache);
+ mmu_free_memory_cache(&vcpu->mmu_rmap_desc_cache);
+}
+
+static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
+ size_t size)
+{
+ void *p;
+
+ BUG_ON(!mc->nobjs);
+ p = mc->objects[--mc->nobjs];
+ memset(p, 0, size);
+ return p;
+}
+
+static void mmu_memory_cache_free(struct kvm_mmu_memory_cache *mc, void *obj)
+{
+ if (mc->nobjs < KVM_NR_MEM_OBJS)
+ mc->objects[mc->nobjs++] = obj;
+ else
+ kfree(obj);
+}
+
+static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
+{
+ return mmu_memory_cache_alloc(&vcpu->mmu_pte_chain_cache,
+ sizeof(struct kvm_pte_chain));
+}
+
+static void mmu_free_pte_chain(struct kvm_vcpu *vcpu,
+ struct kvm_pte_chain *pc)
+{
+ mmu_memory_cache_free(&vcpu->mmu_pte_chain_cache, pc);
+}
+
+static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
+{
+ return mmu_memory_cache_alloc(&vcpu->mmu_rmap_desc_cache,
+ sizeof(struct kvm_rmap_desc));
+}
+
+static void mmu_free_rmap_desc(struct kvm_vcpu *vcpu,
+ struct kvm_rmap_desc *rd)
+{
+ mmu_memory_cache_free(&vcpu->mmu_rmap_desc_cache, rd);
+}
+
/*
* Reverse mapping data structures:
*
@@ -175,7 +253,7 @@ static int is_rmap_pte(u64 pte)
* If page->private bit zero is one, (then page->private & ~1) points
* to a struct kvm_rmap_desc containing more mappings.
*/
-static void rmap_add(struct kvm *kvm, u64 *spte)
+static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte)
{
struct page *page;
struct kvm_rmap_desc *desc;
@@ -189,9 +267,7 @@ static void rmap_add(struct kvm *kvm, u64 *spte)
page->private = (unsigned long)spte;
} else if (!(page->private & 1)) {
rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
- desc = kzalloc(sizeof *desc, GFP_NOWAIT);
- if (!desc)
- BUG(); /* FIXME: return error */
+ desc = mmu_alloc_rmap_desc(vcpu);
desc->shadow_ptes[0] = (u64 *)page->private;
desc->shadow_ptes[1] = spte;
page->private = (unsigned long)desc | 1;
@@ -201,9 +277,7 @@ static void rmap_add(struct kvm *kvm, u64 *spte)
while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
desc = desc->more;
if (desc->shadow_ptes[RMAP_EXT-1]) {
- desc->more = kzalloc(sizeof *desc->more, GFP_NOWAIT);
- if (!desc->more)
- BUG(); /* FIXME: return error */
+ desc->more = mmu_alloc_rmap_desc(vcpu);
desc = desc->more;
}
for (i = 0; desc->shadow_ptes[i]; ++i)
@@ -212,7 +286,8 @@ static void rmap_add(struct kvm *kvm, u64 *spte)
}
}
-static void rmap_desc_remove_entry(struct page *page,
+static void rmap_desc_remove_entry(struct kvm_vcpu *vcpu,
+ struct page *page,
struct kvm_rmap_desc *desc,
int i,
struct kvm_rmap_desc *prev_desc)
@@ -232,10 +307,10 @@ static void rmap_desc_remove_entry(struct page *page,
prev_desc->more = desc->more;
else
page->private = (unsigned long)desc->more | 1;
- kfree(desc);
+ mmu_free_rmap_desc(vcpu, desc);
}
-static void rmap_remove(struct kvm *kvm, u64 *spte)
+static void rmap_remove(struct kvm_vcpu *vcpu, u64 *spte)
{
struct page *page;
struct kvm_rmap_desc *desc;
@@ -263,7 +338,8 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
while (desc) {
for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
if (desc->shadow_ptes[i] == spte) {
- rmap_desc_remove_entry(page, desc, i,
+ rmap_desc_remove_entry(vcpu, page,
+ desc, i,
prev_desc);
return;
}
@@ -274,8 +350,9 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
}
}
-static void rmap_write_protect(struct kvm *kvm, u64 gfn)
+static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
{
+ struct kvm *kvm = vcpu->kvm;
struct page *page;
struct kvm_memory_slot *slot;
struct kvm_rmap_desc *desc;
@@ -298,7 +375,7 @@ static void rmap_write_protect(struct kvm *kvm, u64 gfn)
BUG_ON(!(*spte & PT_PRESENT_MASK));
BUG_ON(!(*spte & PT_WRITABLE_MASK));
rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
- rmap_remove(kvm, spte);
+ rmap_remove(vcpu, spte);
*spte &= ~(u64)PT_WRITABLE_MASK;
}
}
@@ -354,7 +431,8 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
return page;
}
-static void mmu_page_add_parent_pte(struct kvm_mmu_page *page, u64 *parent_pte)
+static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
+ struct kvm_mmu_page *page, u64 *parent_pte)
{
struct kvm_pte_chain *pte_chain;
struct hlist_node *node;
@@ -370,8 +448,7 @@ static void mmu_page_add_parent_pte(struct kvm_mmu_page *page, u64 *parent_pte)
return;
}
page->multimapped = 1;
- pte_chain = kzalloc(sizeof(struct kvm_pte_chain), GFP_NOWAIT);
- BUG_ON(!pte_chain);
+ pte_chain = mmu_alloc_pte_chain(vcpu);
INIT_HLIST_HEAD(&page->parent_ptes);
hlist_add_head(&pte_chain->link, &page->parent_ptes);
pte_chain->parent_ptes[0] = old;
@@ -385,13 +462,14 @@ static void mmu_page_add_parent_pte(struct kvm_mmu_page *page, u64 *parent_pte)
return;
}
}
- pte_chain = kzalloc(sizeof(struct kvm_pte_chain), GFP_NOWAIT);
+ pte_chain = mmu_alloc_pte_chain(vcpu);
BUG_ON(!pte_chain);
hlist_add_head(&pte_chain->link, &page->parent_ptes);
pte_chain->parent_ptes[0] = parent_pte;
}
-static void mmu_page_remove_parent_pte(struct kvm_mmu_page *page,
+static void mmu_page_remove_parent_pte(struct kvm_vcpu *vcpu,
+ struct kvm_mmu_page *page,
u64 *parent_pte)
{
struct kvm_pte_chain *pte_chain;
@@ -418,7 +496,7 @@ static void mmu_page_remove_parent_pte(struct kvm_mmu_page *page,
pte_chain->parent_ptes[i] = NULL;
if (i == 0) {
hlist_del(&pte_chain->link);
- kfree(pte_chain);
+ mmu_free_pte_chain(vcpu, pte_chain);
if (hlist_empty(&page->parent_ptes)) {
page->multimapped = 0;
page->parent_pte = NULL;
@@ -478,7 +556,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
bucket = &vcpu->kvm->mmu_page_hash[index];
hlist_for_each_entry(page, node, bucket, hash_link)
if (page->gfn == gfn && page->role.word == role.word) {
- mmu_page_add_parent_pte(page, parent_pte);
+ mmu_page_add_parent_pte(vcpu, page, parent_pte);
pgprintk("%s: found\n", __FUNCTION__);
return page;
}
@@ -490,7 +568,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
page->role = role;
hlist_add_head(&page->hash_link, bucket);
if (!metaphysical)
- rmap_write_protect(vcpu->kvm, gfn);
+ rmap_write_protect(vcpu, gfn);
return page;
}
@@ -506,7 +584,7 @@ static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
if (page->role.level == PT_PAGE_TABLE_LEVEL) {
for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
if (pt[i] & PT_PRESENT_MASK)
- rmap_remove(vcpu->kvm, &pt[i]);
+ rmap_remove(vcpu, &pt[i]);
pt[i] = 0;
}
return;
@@ -519,7 +597,7 @@ static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
if (!(ent & PT_PRESENT_MASK))
continue;
ent &= PT64_BASE_ADDR_MASK;
- mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
+ mmu_page_remove_parent_pte(vcpu, page_header(ent), &pt[i]);
}
}
@@ -527,7 +605,7 @@ static void kvm_mmu_put_page(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *page,
u64 *parent_pte)
{
- mmu_page_remove_parent_pte(page, parent_pte);
+ mmu_page_remove_parent_pte(vcpu, page, parent_pte);
}
static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu,
@@ -644,7 +722,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
page_header_update_slot(vcpu->kvm, table, v);
table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
PT_USER_MASK;
- rmap_add(vcpu->kvm, &table[index]);
+ rmap_add(vcpu, &table[index]);
return 0;
}
@@ -747,6 +825,8 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
gpa_t addr = gva;
hpa_t paddr;
+ mmu_topup_memory_caches(vcpu);
+
ASSERT(vcpu);
ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
@@ -845,7 +925,7 @@ static inline void set_pte_common(struct kvm_vcpu *vcpu,
mark_page_dirty(vcpu->kvm, gaddr >> PAGE_SHIFT);
page_header_update_slot(vcpu->kvm, shadow_pte, gaddr);
- rmap_add(vcpu->kvm, shadow_pte);
+ rmap_add(vcpu, shadow_pte);
}
static void inject_page_fault(struct kvm_vcpu *vcpu,
@@ -966,8 +1046,15 @@ static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
{
+ int r;
+
destroy_kvm_mmu(vcpu);
- return init_kvm_mmu(vcpu);
+ r = init_kvm_mmu(vcpu);
+ if (r < 0)
+ goto out;
+ mmu_topup_memory_caches(vcpu);
+out:
+ return r;
}
void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
@@ -1030,10 +1117,10 @@ void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
pte = *spte;
if (is_present_pte(pte)) {
if (level == PT_PAGE_TABLE_LEVEL)
- rmap_remove(vcpu->kvm, spte);
+ rmap_remove(vcpu, spte);
else {
child = page_header(pte & PT64_BASE_ADDR_MASK);
- mmu_page_remove_parent_pte(child, spte);
+ mmu_page_remove_parent_pte(vcpu, child, spte);
}
}
*spte = 0;
@@ -1145,10 +1232,12 @@ void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
destroy_kvm_mmu(vcpu);
free_mmu_pages(vcpu);
+ mmu_free_memory_caches(vcpu);
}
-void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
+void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot)
{
+ struct kvm *kvm = vcpu->kvm;
struct kvm_mmu_page *page;
list_for_each_entry(page, &kvm->active_mmu_pages, link) {
@@ -1162,7 +1251,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
/* avoid RMW */
if (pt[i] & PT_WRITABLE_MASK) {
- rmap_remove(kvm, &pt[i]);
+ rmap_remove(vcpu, &pt[i]);
pt[i] &= ~PT_WRITABLE_MASK;
}
}
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 6acb16ea5ce..4e6670ff184 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -323,7 +323,7 @@ static int FNAME(fix_write_pf)(struct kvm_vcpu *vcpu,
mark_page_dirty(vcpu->kvm, gfn);
*shadow_ent |= PT_WRITABLE_MASK;
*guest_ent |= PT_DIRTY_MASK;
- rmap_add(vcpu->kvm, shadow_ent);
+ rmap_add(vcpu, shadow_ent);
return 1;
}
@@ -353,6 +353,9 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
int write_pt = 0;
pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code);
+
+ mmu_topup_memory_caches(vcpu);
+
/*
* Look up the shadow pte for the faulting address.
*/
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-30 23:06:18 +0000