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KVM: MMU: gather remote tlb flush which occurs during page zapped

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Using kvm_mmu_prepare_zap_page() and kvm_mmu_zap_page() instead of
kvm_mmu_zap_page() that can reduce remote tlb flush IPI

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Xiao Guangrong 2010-06-04 21:55:29 +08:00 committed by Avi Kivity
parent 103ad25a86
commit d98ba05365
1 changed files with 53 additions and 31 deletions
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84
arch/x86/kvm/mmu.c
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@ -1200,7 +1200,6 @@ static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
--kvm->stat.mmu_unsync;
}
static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp);
static int kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp,
struct list_head *invalid_list);
static void kvm_mmu_commit_zap_page(struct kvm *kvm,
@ -1218,10 +1217,10 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
(sp)->role.invalid) {} else
static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
bool clear_unsync)
struct list_head *invalid_list, bool clear_unsync)
{
if (sp->role.cr4_pae != !!is_pae(vcpu)) {
kvm_mmu_zap_page(vcpu->kvm, sp);
kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
return 1;
}
@ -1232,7 +1231,7 @@ static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
}
if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
kvm_mmu_zap_page(vcpu->kvm, sp);
kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
return 1;
}
@ -1244,17 +1243,22 @@ static void mmu_convert_notrap(struct kvm_mmu_page *sp);
static int kvm_sync_page_transient(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *sp)
{
LIST_HEAD(invalid_list);
int ret;
ret = __kvm_sync_page(vcpu, sp, false);
ret = __kvm_sync_page(vcpu, sp, &invalid_list, false);
if (!ret)
mmu_convert_notrap(sp);
else
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
return ret;
}
static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
struct list_head *invalid_list)
{
return __kvm_sync_page(vcpu, sp, true);
return __kvm_sync_page(vcpu, sp, invalid_list, true);
}
/* @gfn should be write-protected at the call site */
@ -1262,6 +1266,7 @@ static void kvm_sync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_mmu_page *s;
struct hlist_node *node, *n;
LIST_HEAD(invalid_list);
bool flush = false;
for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node, n) {
@ -1271,13 +1276,14 @@ static void kvm_sync_pages(struct kvm_vcpu *vcpu, gfn_t gfn)
WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
if ((s->role.cr4_pae != !!is_pae(vcpu)) ||
(vcpu->arch.mmu.sync_page(vcpu, s))) {
kvm_mmu_zap_page(vcpu->kvm, s);
kvm_mmu_prepare_zap_page(vcpu->kvm, s, &invalid_list);
continue;
}
kvm_unlink_unsync_page(vcpu->kvm, s);
flush = true;
}
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
if (flush)
kvm_mmu_flush_tlb(vcpu);
}
@ -1348,6 +1354,7 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu,
struct kvm_mmu_page *sp;
struct mmu_page_path parents;
struct kvm_mmu_pages pages;
LIST_HEAD(invalid_list);
kvm_mmu_pages_init(parent, &parents, &pages);
while (mmu_unsync_walk(parent, &pages)) {
@ -1360,9 +1367,10 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu,
kvm_flush_remote_tlbs(vcpu->kvm);
for_each_sp(pages, sp, parents, i) {
kvm_sync_page(vcpu, sp);
kvm_sync_page(vcpu, sp, &invalid_list);
mmu_pages_clear_parents(&parents);
}
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
cond_resched_lock(&vcpu->kvm->mmu_lock);
kvm_mmu_pages_init(parent, &parents, &pages);
}
@ -1606,16 +1614,6 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
}
static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
{
LIST_HEAD(invalid_list);
int ret;
ret = kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
kvm_mmu_commit_zap_page(kvm, &invalid_list);
return ret;
}
/*
* Changing the number of mmu pages allocated to the vm
* Note: if kvm_nr_mmu_pages is too small, you will get dead lock
@ -1623,6 +1621,7 @@ static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
{
int used_pages;
LIST_HEAD(invalid_list);
used_pages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages;
used_pages = max(0, used_pages);
@ -1640,8 +1639,10 @@ void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
page = container_of(kvm->arch.active_mmu_pages.prev,
struct kvm_mmu_page, link);
used_pages -= kvm_mmu_zap_page(kvm, page);
used_pages -= kvm_mmu_prepare_zap_page(kvm, page,
&invalid_list);
}
kvm_mmu_commit_zap_page(kvm, &invalid_list);
kvm_nr_mmu_pages = used_pages;
kvm->arch.n_free_mmu_pages = 0;
}
@ -1656,6 +1657,7 @@ static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
{
struct kvm_mmu_page *sp;
struct hlist_node *node, *n;
LIST_HEAD(invalid_list);
int r;
pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
@ -1665,9 +1667,10 @@ restart:
pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
sp->role.word);
r = 1;
if (kvm_mmu_zap_page(kvm, sp))
if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list))
goto restart;
}
kvm_mmu_commit_zap_page(kvm, &invalid_list);
return r;
}
@ -1675,14 +1678,16 @@ static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
{
struct kvm_mmu_page *sp;
struct hlist_node *node, *nn;
LIST_HEAD(invalid_list);
restart:
for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node, nn) {
pgprintk("%s: zap %lx %x\n",
__func__, gfn, sp->role.word);
if (kvm_mmu_zap_page(kvm, sp))
if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list))
goto restart;
}
kvm_mmu_commit_zap_page(kvm, &invalid_list);
}
static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
@ -2123,6 +2128,7 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
{
int i;
struct kvm_mmu_page *sp;
LIST_HEAD(invalid_list);
if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
return;
@ -2132,8 +2138,10 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
sp = page_header(root);
--sp->root_count;
if (!sp->root_count && sp->role.invalid)
kvm_mmu_zap_page(vcpu->kvm, sp);
if (!sp->root_count && sp->role.invalid) {
kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list);
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
}
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
spin_unlock(&vcpu->kvm->mmu_lock);
return;
@ -2146,10 +2154,12 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
sp = page_header(root);
--sp->root_count;
if (!sp->root_count && sp->role.invalid)
kvm_mmu_zap_page(vcpu->kvm, sp);
kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
&invalid_list);
}
vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
}
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
spin_unlock(&vcpu->kvm->mmu_lock);
vcpu->arch.mmu.root_hpa = INVALID_PAGE;
}
@ -2715,6 +2725,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
gfn_t gfn = gpa >> PAGE_SHIFT;
struct kvm_mmu_page *sp;
struct hlist_node *node, *n;
LIST_HEAD(invalid_list);
u64 entry, gentry;
u64 *spte;
unsigned offset = offset_in_page(gpa);
@ -2801,7 +2812,8 @@ restart:
*/
pgprintk("misaligned: gpa %llx bytes %d role %x\n",
gpa, bytes, sp->role.word);
if (kvm_mmu_zap_page(vcpu->kvm, sp))
if (kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
&invalid_list))
goto restart;
++vcpu->kvm->stat.mmu_flooded;
continue;
@ -2836,6 +2848,7 @@ restart:
++spte;
}
}
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
kvm_mmu_audit(vcpu, "post pte write");
spin_unlock(&vcpu->kvm->mmu_lock);
if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
@ -2864,6 +2877,7 @@ EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
{
int free_pages;
LIST_HEAD(invalid_list);
free_pages = vcpu->kvm->arch.n_free_mmu_pages;
while (free_pages < KVM_REFILL_PAGES &&
@ -2872,9 +2886,11 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
struct kvm_mmu_page, link);
free_pages += kvm_mmu_zap_page(vcpu->kvm, sp);
free_pages += kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
&invalid_list);
++vcpu->kvm->stat.mmu_recycled;
}
kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
}
int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
@ -3009,25 +3025,28 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
void kvm_mmu_zap_all(struct kvm *kvm)
{
struct kvm_mmu_page *sp, *node;
LIST_HEAD(invalid_list);
spin_lock(&kvm->mmu_lock);
restart:
list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
if (kvm_mmu_zap_page(kvm, sp))
if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list))
goto restart;
kvm_mmu_commit_zap_page(kvm, &invalid_list);
spin_unlock(&kvm->mmu_lock);
kvm_flush_remote_tlbs(kvm);
}
static int kvm_mmu_remove_some_alloc_mmu_pages(struct kvm *kvm)
static int kvm_mmu_remove_some_alloc_mmu_pages(struct kvm *kvm,
struct list_head *invalid_list)
{
struct kvm_mmu_page *page;
page = container_of(kvm->arch.active_mmu_pages.prev,
struct kvm_mmu_page, link);
return kvm_mmu_zap_page(kvm, page);
return kvm_mmu_prepare_zap_page(kvm, page, invalid_list);
}
static int mmu_shrink(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
@ -3040,6 +3059,7 @@ static int mmu_shrink(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
list_for_each_entry(kvm, &vm_list, vm_list) {
int npages, idx, freed_pages;
LIST_HEAD(invalid_list);
idx = srcu_read_lock(&kvm->srcu);
spin_lock(&kvm->mmu_lock);
@ -3047,12 +3067,14 @@ static int mmu_shrink(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
kvm->arch.n_free_mmu_pages;
cache_count += npages;
if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
freed_pages = kvm_mmu_remove_some_alloc_mmu_pages(kvm);
freed_pages = kvm_mmu_remove_some_alloc_mmu_pages(kvm,
&invalid_list);
cache_count -= freed_pages;
kvm_freed = kvm;
}
nr_to_scan--;
kvm_mmu_commit_zap_page(kvm, &invalid_list);
spin_unlock(&kvm->mmu_lock);
srcu_read_unlock(&kvm->srcu, idx);
}