[PATCH v3 08/19] KVM: MMU: count used shadow pages on prepareing path

Xiao Guangrong
2011-06-30T08:20:59Z

Move counting used shadow pages from commiting path to preparing path to
reduce tlb flush on some paths

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/kvm/mmu.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a62ba46..91d3069 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1039,7 +1039,7 @@ static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, int nr)
percpu_counter_add(&kvm_total_used_mmu_pages, nr);
}

-static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+static void kvm_mmu_free_page(struct kvm_mmu_page *sp)
{
ASSERT(is_empty_shadow_page(sp->spt));
hlist_del(&sp->hash_link);
@@ -1048,7 +1048,6 @@ static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
if (!sp->role.direct)
free_page((unsigned long)sp->gfns);
kmem_cache_free(mmu_page_header_cache, sp);
- kvm_mod_used_mmu_pages(kvm, -1);
}

static unsigned kvm_page_table_hashfn(gfn_t gfn)
@@ -1655,6 +1654,7 @@ static int kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp,
/* Count self */
ret++;
list_move(&sp->link, invalid_list);
+ kvm_mod_used_mmu_pages(kvm, -1);
} else {
list_move(&sp->link, &kvm->arch.active_mmu_pages);
kvm_reload_remote_mmus(kvm);
@@ -1678,7 +1678,7 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
do {
sp = list_first_entry(invalid_list, struct kvm_mmu_page, link);
WARN_ON(!sp->role.invalid || sp->root_count);
- kvm_mmu_free_page(kvm, sp);
+ kvm_mmu_free_page(sp);
} while (!list_empty(invalid_list));

}
@@ -1704,8 +1704,8 @@ void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int goal_nr_mmu_pages)
page = container_of(kvm->arch.active_mmu_pages.prev,
struct kvm_mmu_page, link);
kvm_mmu_prepare_zap_page(kvm, page, &invalid_list);
- kvm_mmu_commit_zap_page(kvm, &invalid_list);
}
+ kvm_mmu_commit_zap_page(kvm, &invalid_list);
goal_nr_mmu_pages = kvm->arch.n_used_mmu_pages;
}

@@ -3302,9 +3302,9 @@ 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);
kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list);
- kvm_mmu_commit_zap_page(vcpu->kvm, &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,
--
1.7.5.4