From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756595AbYCKMFQ (ORCPT ); Tue, 11 Mar 2008 08:05:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752946AbYCKMFE (ORCPT ); Tue, 11 Mar 2008 08:05:04 -0400 Received: from ozlabs.org ([203.10.76.45]:55519 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751464AbYCKMFD (ORCPT ); Tue, 11 Mar 2008 08:05:03 -0400 From: Rusty Russell To: virtualization@lists.linux-foundation.org Subject: [PATCH 1/4] virtio: Use spin_lock_irqsave/restore for virtio-pci Date: Tue, 11 Mar 2008 23:03:22 +1100 User-Agent: KMail/1.9.6 (enterprise 0.20070907.709405) Cc: linux-kernel@vger.kernel.org, Anthony Liguori MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200803112303.22984.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anthony Liguori virtio-pci acquires its spin lock in an interrupt context so it's necessary to use spin_lock_irqsave/restore variants. This patch fixes guest SMP when using virtio devices in KVM. Signed-off-by: Anthony Liguori Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 26f787d..59a8f73 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -177,6 +177,7 @@ static irqreturn_t vp_interrupt(int irq, void *opaque) struct virtio_pci_device *vp_dev = opaque; struct virtio_pci_vq_info *info; irqreturn_t ret = IRQ_NONE; + unsigned long flags; u8 isr; /* reading the ISR has the effect of also clearing it so it's very @@ -197,12 +198,12 @@ static irqreturn_t vp_interrupt(int irq, void *opaque) drv->config_changed(&vp_dev->vdev); } - spin_lock(&vp_dev->lock); + spin_lock_irqsave(&vp_dev->lock, flags); list_for_each_entry(info, &vp_dev->virtqueues, node) { if (vring_interrupt(irq, info->vq) == IRQ_HANDLED) ret = IRQ_HANDLED; } - spin_unlock(&vp_dev->lock); + spin_unlock_irqrestore(&vp_dev->lock, flags); return ret; } @@ -214,6 +215,7 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index, struct virtio_pci_device *vp_dev = to_vp_device(vdev); struct virtio_pci_vq_info *info; struct virtqueue *vq; + unsigned long flags; u16 num; int err; @@ -255,9 +257,9 @@ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index, vq->priv = info; info->vq = vq; - spin_lock(&vp_dev->lock); + spin_lock_irqsave(&vp_dev->lock, flags); list_add(&info->node, &vp_dev->virtqueues); - spin_unlock(&vp_dev->lock); + spin_unlock_irqrestore(&vp_dev->lock, flags); return vq; @@ -274,10 +276,11 @@ static void vp_del_vq(struct virtqueue *vq) { struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); struct virtio_pci_vq_info *info = vq->priv; + unsigned long flags; - spin_lock(&vp_dev->lock); + spin_lock_irqsave(&vp_dev->lock, flags); list_del(&info->node); - spin_unlock(&vp_dev->lock); + spin_unlock_irqrestore(&vp_dev->lock, flags); vring_del_virtqueue(vq);