diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e733262027ed..cb9fd69d2632 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -5846,18 +5846,14 @@ void kvm_mmu_slot_set_dirty(struct kvm *kvm, } EXPORT_SYMBOL_GPL(kvm_mmu_slot_set_dirty); -#define BATCH_ZAP_PAGES 10 static void kvm_zap_obsolete_pages(struct kvm *kvm) { struct kvm_mmu_page *sp, *node; LIST_HEAD(invalid_list); - int batch = 0; restart: list_for_each_entry_safe_reverse(sp, node, &kvm->arch.active_mmu_pages, link) { - int ret; - /* * No obsolete page exists before new created page since * active_mmu_pages is the FIFO list. @@ -5866,6 +5862,28 @@ restart: break; /* + * Do not repeatedly zap a root page to avoid unnecessary + * KVM_REQ_MMU_RELOAD, otherwise we may not be able to + * progress: + * vcpu 0 vcpu 1 + * call vcpu_enter_guest(): + * 1): handle KVM_REQ_MMU_RELOAD + * and require mmu-lock to + * load mmu + * repeat: + * 1): zap root page and + * send KVM_REQ_MMU_RELOAD + * + * 2): if (cond_resched_lock(mmu-lock)) + * + * 2): hold mmu-lock and load mmu + * + * 3): see KVM_REQ_MMU_RELOAD bit + * on vcpu->requests is set + * then return 1 to call + * vcpu_enter_guest() again. + * goto repeat; + * * Since we are reversely walking the list and the invalid * list will be moved to the head, skip the invalid page * can help us to avoid the infinity list walking. @@ -5873,18 +5891,13 @@ restart: if (sp->role.invalid) continue; - if (batch >= BATCH_ZAP_PAGES && - (need_resched() || spin_needbreak(&kvm->mmu_lock))) { - batch = 0; + if (need_resched() || spin_needbreak(&kvm->mmu_lock)) { kvm_mmu_commit_zap_page(kvm, &invalid_list); cond_resched_lock(&kvm->mmu_lock); goto restart; } - ret = kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); - batch += ret; - - if (ret) + if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list)) goto restart; } |