LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Rusty Russell <rusty@rustcorp.com.au>
To: virtualization@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org, Anthony Liguori <aliguori@us.ibm.com>
Subject: [PATCH 1/4] virtio: Use spin_lock_irqsave/restore for virtio-pci
Date: Tue, 11 Mar 2008 23:03:22 +1100	[thread overview]
Message-ID: <200803112303.22984.rusty@rustcorp.com.au> (raw)

From: Anthony Liguori <aliguori@us.ibm.com>

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 <aliguori@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 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);
 


             reply	other threads:[~2008-03-11 12:05 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-11 12:03 Rusty Russell [this message]
2008-03-11 12:04 ` [PATCH 2/4] virtio: Fix sysfs bits to have proper block symlink Rusty Russell
2008-03-11 12:05   ` [PATCH 3/4] virtio: handle > 2 billion page balloon targets Rusty Russell
2008-03-11 12:06     ` [PATCH 4/4] virtio: Enable netpoll interface for netconsole logging Rusty Russell

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=200803112303.22984.rusty@rustcorp.com.au \
    --to=rusty@rustcorp.com.au \
    --cc=aliguori@us.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=virtualization@lists.linux-foundation.org \
    --subject='Re: [PATCH 1/4] virtio: Use spin_lock_irqsave/restore for virtio-pci' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).