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Date: Sun, 15 May 2011 05:44:34 +0800
From: Xiao Guangrong <xiaoguangrong@...fujitsu.com>
To: Avi Kivity <avi@...hat.com>
CC: Marcelo Tosatti <mtosatti@...hat.com>,
LKML <linux-kernel@...r.kernel.org>, KVM <kvm@...r.kernel.org>
Subject: [PATCH 5/7] KVM: MMU: remove the arithmetic of parent pte rmap
Parent pte rmap and page rmap are very similar, so use the same arithmetic for
them
Signed-off-by: Xiao Guangrong <xiaoguangrong@...fujitsu.com>
---
arch/x86/include/asm/kvm_host.h | 7 +--
arch/x86/kvm/mmu.c | 178 ++++++++++-----------------------------
2 files changed, 45 insertions(+), 140 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index d2e5fb8..71c0b86 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -227,14 +227,10 @@ struct kvm_mmu_page {
* in this shadow page.
*/
DECLARE_BITMAP(slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
- bool multimapped; /* More than one parent_pte? */
bool unsync;
int root_count; /* Currently serving as active root */
unsigned int unsync_children;
- union {
- u64 *parent_pte; /* !multimapped */
- struct hlist_head parent_ptes; /* multimapped, kvm_pte_chain */
- };
+ unsigned long rmap; /* Rmap for parent_pte */
DECLARE_BITMAP(unsync_child_bitmap, 512);
};
@@ -346,7 +342,6 @@ struct kvm_vcpu_arch {
* put it here to avoid allocation */
struct kvm_pv_mmu_op_buffer mmu_op_buffer;
- struct kvm_mmu_memory_cache mmu_pte_chain_cache;
struct kvm_mmu_memory_cache mmu_rmap_desc_cache;
struct kvm_mmu_memory_cache mmu_page_cache;
struct kvm_mmu_memory_cache mmu_page_header_cache;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8da77b3..b68f42c 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -182,8 +182,6 @@ struct kvm_shadow_walk_iterator {
shadow_walk_okay(&(_walker)); \
shadow_walk_next(&(_walker)))
-typedef void (*mmu_parent_walk_fn) (struct kvm_mmu_page *sp, u64 *spte);
-
static struct kmem_cache *pte_chain_cache;
static struct kmem_cache *rmap_desc_cache;
static struct kmem_cache *mmu_page_header_cache;
@@ -397,12 +395,8 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
{
int r;
- r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
- pte_chain_cache, 4);
- if (r)
- goto out;
r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
- rmap_desc_cache, 4 + PTE_PREFETCH_NUM);
+ rmap_desc_cache, 8 + PTE_PREFETCH_NUM);
if (r)
goto out;
r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
@@ -416,7 +410,6 @@ out:
static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
{
- mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache, pte_chain_cache);
mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache, rmap_desc_cache);
mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache,
@@ -433,17 +426,6 @@ static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
return p;
}
-static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
-{
- return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
- sizeof(struct kvm_pte_chain));
-}
-
-static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
-{
- kmem_cache_free(pte_chain_cache, pc);
-}
-
static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
{
return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
@@ -634,6 +616,26 @@ static int __rmap_add(struct kvm_vcpu *vcpu, u64 *spte, unsigned long *rmapp)
return count;
}
+typedef void (*__rmap_walk_fn) (u64 *spte);
+static void __rmap_walk(unsigned long *rmapp, __rmap_walk_fn fn)
+{
+ struct kvm_rmap_desc *desc;
+ int i;
+
+ if (!*rmapp)
+ return;
+
+ if (!(*rmapp & 1))
+ return fn((u64 *)*rmapp);
+
+ desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
+ while (desc) {
+ for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i)
+ fn(desc->sptes[i]);
+ desc = desc->more;
+ }
+}
+
static u64 *__rmap_next(unsigned long *rmapp, u64 *spte)
{
struct kvm_rmap_desc *desc;
@@ -1067,134 +1069,52 @@ static unsigned kvm_page_table_hashfn(gfn_t gfn)
return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
}
-static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
- u64 *parent_pte, int direct)
-{
- struct kvm_mmu_page *sp;
-
- sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
- sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
- if (!direct)
- sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache,
- PAGE_SIZE);
- set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
- list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
- bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
- sp->multimapped = 0;
- sp->parent_pte = parent_pte;
- kvm_mod_used_mmu_pages(vcpu->kvm, +1);
- return sp;
-}
-
static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *sp, u64 *parent_pte)
{
- struct kvm_pte_chain *pte_chain;
- struct hlist_node *node;
- int i;
-
if (!parent_pte)
return;
- if (!sp->multimapped) {
- u64 *old = sp->parent_pte;
- if (!old) {
- sp->parent_pte = parent_pte;
- return;
- }
- sp->multimapped = 1;
- pte_chain = mmu_alloc_pte_chain(vcpu);
- INIT_HLIST_HEAD(&sp->parent_ptes);
- hlist_add_head(&pte_chain->link, &sp->parent_ptes);
- pte_chain->parent_ptes[0] = old;
- }
- hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
- if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
- continue;
- for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
- if (!pte_chain->parent_ptes[i]) {
- pte_chain->parent_ptes[i] = parent_pte;
- return;
- }
- }
- pte_chain = mmu_alloc_pte_chain(vcpu);
- BUG_ON(!pte_chain);
- hlist_add_head(&pte_chain->link, &sp->parent_ptes);
- pte_chain->parent_ptes[0] = parent_pte;
+ __rmap_add(vcpu, parent_pte, &sp->rmap);
}
static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
u64 *parent_pte)
{
- struct kvm_pte_chain *pte_chain;
- struct hlist_node *node;
- int i;
-
- if (!sp->multimapped) {
- BUG_ON(sp->parent_pte != parent_pte);
- sp->parent_pte = NULL;
- return;
- }
- hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
- for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
- if (!pte_chain->parent_ptes[i])
- break;
- if (pte_chain->parent_ptes[i] != parent_pte)
- continue;
- while (i + 1 < NR_PTE_CHAIN_ENTRIES
- && pte_chain->parent_ptes[i + 1]) {
- pte_chain->parent_ptes[i]
- = pte_chain->parent_ptes[i + 1];
- ++i;
- }
- pte_chain->parent_ptes[i] = NULL;
- if (i == 0) {
- hlist_del(&pte_chain->link);
- mmu_free_pte_chain(pte_chain);
- if (hlist_empty(&sp->parent_ptes)) {
- sp->multimapped = 0;
- sp->parent_pte = NULL;
- }
- }
- return;
- }
- BUG();
+ __rmap_remove(parent_pte, &sp->rmap);
}
-static void mmu_parent_walk(struct kvm_mmu_page *sp, mmu_parent_walk_fn fn)
+static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
+ u64 *parent_pte, int direct)
{
- struct kvm_pte_chain *pte_chain;
- struct hlist_node *node;
- struct kvm_mmu_page *parent_sp;
- int i;
-
- if (!sp->multimapped && sp->parent_pte) {
- parent_sp = page_header(__pa(sp->parent_pte));
- fn(parent_sp, sp->parent_pte);
- return;
- }
-
- hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
- for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
- u64 *spte = pte_chain->parent_ptes[i];
+ struct kvm_mmu_page *sp;
- if (!spte)
- break;
- parent_sp = page_header(__pa(spte));
- fn(parent_sp, spte);
- }
+ sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
+ sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
+ if (!direct)
+ sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache,
+ PAGE_SIZE);
+ set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
+ list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
+ bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
+ sp->rmap = 0;
+ mmu_page_add_parent_pte(vcpu, sp, parent_pte);
+ kvm_mod_used_mmu_pages(vcpu->kvm, +1);
+ return sp;
}
-static void mark_unsync(struct kvm_mmu_page *sp, u64 *spte);
+static void mark_unsync(u64 *spte);
static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp)
{
- mmu_parent_walk(sp, mark_unsync);
+ __rmap_walk(&sp->rmap, mark_unsync);
}
-static void mark_unsync(struct kvm_mmu_page *sp, u64 *spte)
+static void mark_unsync(u64 *spte)
{
+ struct kvm_mmu_page *sp;
unsigned int index;
+ sp = page_header(__pa(spte));
index = spte - sp->spt;
if (__test_and_set_bit(index, sp->unsync_child_bitmap))
return;
@@ -1692,17 +1612,7 @@ static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
{
u64 *parent_pte;
- while (sp->multimapped || sp->parent_pte) {
- if (!sp->multimapped)
- parent_pte = sp->parent_pte;
- else {
- struct kvm_pte_chain *chain;
-
- chain = container_of(sp->parent_ptes.first,
- struct kvm_pte_chain, link);
- parent_pte = chain->parent_ptes[0];
- }
- BUG_ON(!parent_pte);
+ while ((parent_pte = __rmap_next(&sp->rmap, NULL))) {
kvm_mmu_put_page(sp, parent_pte);
__set_spte(parent_pte, shadow_trap_nonpresent_pte);
}
--
1.7.4.4
--
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