From bd4c86eaa6ff10abc4e00d0f45d2a28b10b09df4 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Tue, 12 Jul 2011 03:27:14 +0800 Subject: [PATCH] KVM: MMU: split kvm_mmu_free_page Split kvm_mmu_free_page to kvm_mmu_isolate_page and kvm_mmu_free_page One is used to remove the page from cache under mmu lock and the other is used to free page table out of mmu lock Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 91d30695677b..2f8543c65fa3 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1039,14 +1039,28 @@ 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_mmu_page *sp) +/* + * Remove the sp from shadow page cache, after call it, + * we can not find this sp from the cache, and the shadow + * page table is still valid. + * It should be under the protection of mmu lock. + */ +static void kvm_mmu_isolate_page(struct kvm_mmu_page *sp) { ASSERT(is_empty_shadow_page(sp->spt)); hlist_del(&sp->hash_link); - list_del(&sp->link); - free_page((unsigned long)sp->spt); if (!sp->role.direct) free_page((unsigned long)sp->gfns); +} + +/* + * Free the shadow page table and the sp, we can do it + * out of the protection of mmu lock. + */ +static void kvm_mmu_free_page(struct kvm_mmu_page *sp) +{ + list_del(&sp->link); + free_page((unsigned long)sp->spt); kmem_cache_free(mmu_page_header_cache, sp); } @@ -1678,6 +1692,7 @@ 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_isolate_page(sp); kvm_mmu_free_page(sp); } while (!list_empty(invalid_list));