From patchwork Mon Aug 24 08:54:22 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gleb Natapov X-Patchwork-Id: 43572 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n7O8t0lI005378 for ; Mon, 24 Aug 2009 08:55:01 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752004AbZHXIyb (ORCPT ); Mon, 24 Aug 2009 04:54:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752055AbZHXIyb (ORCPT ); Mon, 24 Aug 2009 04:54:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34406 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752004AbZHXIy1 (ORCPT ); Mon, 24 Aug 2009 04:54:27 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n7O8sTPf007051 for ; Mon, 24 Aug 2009 04:54:29 -0400 Received: from dhcp-1-237.tlv.redhat.com (dhcp-1-237.tlv.redhat.com [10.35.1.237]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id n7O8sSR7013693; Mon, 24 Aug 2009 04:54:29 -0400 Received: by dhcp-1-237.tlv.redhat.com (Postfix, from userid 13519) id 8234718D46C; Mon, 24 Aug 2009 11:54:26 +0300 (IDT) From: Gleb Natapov To: avi@redhat.com Cc: kvm@vger.kernel.org Subject: [PATCH v4 5/9] Move irq routing data structure to rcu locking Date: Mon, 24 Aug 2009 11:54:22 +0300 Message-Id: <1251104066-23504-6-git-send-email-gleb@redhat.com> In-Reply-To: <1251104066-23504-1-git-send-email-gleb@redhat.com> References: <1251104066-23504-1-git-send-email-gleb@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Signed-off-by: Gleb Natapov --- virt/kvm/irq_comm.c | 16 +++++++++++----- 1 files changed, 11 insertions(+), 5 deletions(-) diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c index 6a8434d..8350050 100644 --- a/virt/kvm/irq_comm.c +++ b/virt/kvm/irq_comm.c @@ -159,7 +159,8 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level) * IOAPIC. So set the bit in both. The guest will ignore * writes to the unused one. */ - irq_rt = kvm->irq_routing; + rcu_read_lock(); + irq_rt = rcu_dereference(kvm->irq_routing); if (irq < irq_rt->nr_rt_entries) hlist_for_each_entry(e, n, &irq_rt->map[irq], link) { int r = e->set(e, kvm, irq_source_id, level); @@ -168,6 +169,7 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level) ret = r + ((ret < 0) ? 0 : ret); } + rcu_read_unlock(); return ret; } @@ -179,7 +181,10 @@ void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin) trace_kvm_ack_irq(irqchip, pin); - gsi = kvm->irq_routing->chip[irqchip][pin]; + rcu_read_lock(); + gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin]; + rcu_read_unlock(); + if (gsi != -1) hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link) @@ -277,9 +282,9 @@ void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask) void kvm_free_irq_routing(struct kvm *kvm) { - mutex_lock(&kvm->irq_lock); + /* Called only during vm destruction. Nobody can use the pointer + at this stage */ kfree(kvm->irq_routing); - mutex_unlock(&kvm->irq_lock); } static int setup_routing_entry(struct kvm_irq_routing_table *rt, @@ -385,8 +390,9 @@ int kvm_set_irq_routing(struct kvm *kvm, mutex_lock(&kvm->irq_lock); old = kvm->irq_routing; - kvm->irq_routing = new; + rcu_assign_pointer(kvm->irq_routing, new); mutex_unlock(&kvm->irq_lock); + synchronize_rcu(); new = old; r = 0;