From patchwork Mon Jun 29 17:34:30 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 33001 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 n5THbfWE013854 for ; Mon, 29 Jun 2009 17:37:41 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758077AbZF2Rf0 (ORCPT ); Mon, 29 Jun 2009 13:35:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758050AbZF2RfZ (ORCPT ); Mon, 29 Jun 2009 13:35:25 -0400 Received: from mx2.redhat.com ([66.187.237.31]:39862 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757881AbZF2RfO (ORCPT ); Mon, 29 Jun 2009 13:35:14 -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 n5THZ4g6023213; Mon, 29 Jun 2009 13:35:04 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n5THZ2ZW019860; Mon, 29 Jun 2009 13:35:03 -0400 Received: from redhat.com (vpn-6-102.tlv.redhat.com [10.35.6.102]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id n5THYwjn015660; Mon, 29 Jun 2009 13:34:59 -0400 Date: Mon, 29 Jun 2009 20:34:30 +0300 From: "Michael S. Tsirkin" To: Gregory Haskins , avi@redhat.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, avi@redhat.com, mtosatti@redhat.com, paulmck@linux.vnet.ibm.com, markmc@redhat.com Subject: [PATCHv4 4/6] kvm: convert bus to slots_lock Message-ID: <20090629173430.GE22855@redhat.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) X-Scanned-By: MIMEDefang 2.58 on 172.16.27.26 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Use slots_lock to protect device list on the bus. slots_lock is already taken for read everywhere, so we only need to take it for write when registering devices. This is in preparation to removing in_range and kvm->lock around it. Signed-off-by: Michael S. Tsirkin --- arch/x86/kvm/i8254.c | 5 +++-- arch/x86/kvm/i8259.c | 2 +- include/linux/kvm_host.h | 5 ++++- virt/kvm/ioapic.c | 2 +- virt/kvm/kvm_main.c | 12 +++++++++++- 5 files changed, 20 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 331705f..360dccf 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -582,6 +582,7 @@ static const struct kvm_io_device_ops speaker_dev_ops = { .in_range = speaker_in_range, }; +/* Caller must have writers lock on slots_lock */ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) { struct kvm_pit *pit; @@ -620,11 +621,11 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); kvm_iodevice_init(&pit->dev, &pit_dev_ops); - kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev); + __kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev); if (flags & KVM_PIT_SPEAKER_DUMMY) { kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops); - kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev); + __kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &pit->speaker_dev); } return pit; diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index 148c52a..1851aec 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -548,6 +548,6 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm) * Initialize PIO device */ kvm_iodevice_init(&s->dev, &picdev_ops); - kvm_io_bus_register_dev(&kvm->pio_bus, &s->dev); + kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev); return s; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 2451f48..889b608 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -42,6 +42,7 @@ #define KVM_USERSPACE_IRQ_SOURCE_ID 0 +struct kvm; struct kvm_vcpu; extern struct kmem_cache *kvm_vcpu_cache; @@ -61,7 +62,9 @@ void kvm_io_bus_init(struct kvm_io_bus *bus); void kvm_io_bus_destroy(struct kvm_io_bus *bus); struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus, gpa_t addr, int len, int is_write); -void kvm_io_bus_register_dev(struct kvm_io_bus *bus, +void __kvm_io_bus_register_dev(struct kvm_io_bus *bus, + struct kvm_io_device *dev); +void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, struct kvm_io_device *dev); struct kvm_vcpu { diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index d8b2eca..ad80ead 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -343,7 +343,7 @@ int kvm_ioapic_init(struct kvm *kvm) kvm_ioapic_reset(ioapic); kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops); ioapic->kvm = kvm; - kvm_io_bus_register_dev(&kvm->mmio_bus, &ioapic->dev); + kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &ioapic->dev); return 0; } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 58d6bc6..7cae1b7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2499,7 +2499,17 @@ struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus, return NULL; } -void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev) +void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus, + struct kvm_io_device *dev) +{ + down_write(&kvm->slots_lock); + __kvm_io_bus_register_dev(bus, dev); + up_write(&kvm->slots_lock); +} + +/* An unlocked version. Caller must have write lock on slots_lock. */ +void __kvm_io_bus_register_dev(struct kvm_io_bus *bus, + struct kvm_io_device *dev) { BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));