From 27ebe308af7c14aed0711e25817c6a1235bd16ff Mon Sep 17 00:00:00 2001 From: Anthony Liguori Date: Sun, 2 Mar 2008 16:37:48 -0600 Subject: [PATCH] virtio: Use spin_lock_irqsave/restore for virtio-pci 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 26f787ddd5..59a8f73dec 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); -- 2.39.5