From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: [PATCH 1/5] Protect irq_sources_bitmap by kvm->lock instead of kvm->irq_lock Date: Mon, 13 Jul 2009 12:12:31 +0300 Message-ID: <1247476355-27284-2-git-send-email-gleb@redhat.com> References: <1247476355-27284-1-git-send-email-gleb@redhat.com> Cc: avi@redhat.com, mtosatti@redhat.com To: kvm@vger.kernel.org Return-path: Received: from mx2.redhat.com ([66.187.237.31]:35131 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753302AbZGMJMj (ORCPT ); Mon, 13 Jul 2009 05:12:39 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n6D9Cdir031639 for ; Mon, 13 Jul 2009 05:12:39 -0400 In-Reply-To: <1247476355-27284-1-git-send-email-gleb@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: It is already protected by kvm->lock on device assignment path. Just take the same lock in the PIT code. Signed-off-by: Gleb Natapov --- arch/x86/kvm/i8254.c | 2 ++ virt/kvm/irq_comm.c | 8 ++++---- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 05e00a8..e1b9016 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -596,7 +596,9 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) if (!pit) return NULL; + mutex_lock(&kvm->lock); pit->irq_source_id = kvm_request_irq_source_id(kvm); + mutex_unlock(&kvm->lock); if (pit->irq_source_id < 0) { kfree(pit); return NULL; diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c index 6c57e46..ce8fcd3 100644 --- a/virt/kvm/irq_comm.c +++ b/virt/kvm/irq_comm.c @@ -210,7 +210,8 @@ int kvm_request_irq_source_id(struct kvm *kvm) unsigned long *bitmap = &kvm->arch.irq_sources_bitmap; int irq_source_id; - mutex_lock(&kvm->irq_lock); + WARN_ON(!mutex_is_locked(&kvm->lock)); + irq_source_id = find_first_zero_bit(bitmap, sizeof(kvm->arch.irq_sources_bitmap)); @@ -221,7 +222,6 @@ int kvm_request_irq_source_id(struct kvm *kvm) ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID); set_bit(irq_source_id, bitmap); - mutex_unlock(&kvm->irq_lock); return irq_source_id; } @@ -230,9 +230,10 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id) { int i; + /* during vm destruction this function is called without locking */ + WARN_ON(!mutex_is_locked(&kvm->lock) && atomic_read(&kvm->users_count)); ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID); - mutex_lock(&kvm->irq_lock); if (irq_source_id < 0 || irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) { printk(KERN_ERR "kvm: IRQ source ID out of range!\n"); @@ -241,7 +242,6 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id) for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) clear_bit(irq_source_id, &kvm->arch.irq_states[i]); clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap); - mutex_unlock(&kvm->irq_lock); } void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq, -- 1.6.2.1