From: "Michael S. Tsirkin" <mst@redhat.com>
To: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: Re: [PATCH 05/16] virtio: defer config changed notifications
Date: Mon, 6 Oct 2014 15:00:07 +0300 [thread overview]
Message-ID: <20141006120007.GA26328@redhat.com> (raw)
In-Reply-To: <20141006133338.236a1175.cornelia.huck@de.ibm.com>
On Mon, Oct 06, 2014 at 01:33:38PM +0200, Cornelia Huck wrote:
> On Sun, 5 Oct 2014 19:07:05 +0300
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
>
> > Defer config changed notifications that arrive during
> > probe/scan/freeze/restore.
> >
> > This will allow drivers to set DRIVER_OK earlier, without worrying about
> > racing with config change interrupts.
> >
> > This change will also benefit old hypervisors (before 2009)
> > that send interrupts without checking DRIVER_OK: previously,
> > the callback could race with driver-specific initialization.
> >
> > This will also help simplify drivers.
> >
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> > include/linux/virtio.h | 6 ++++++
> > drivers/virtio/virtio.c | 55 +++++++++++++++++++++++++++++++++++++++++--------
> > 2 files changed, 52 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> > index 657f817..578e02d 100644
> > --- a/drivers/virtio/virtio.c
> > +++ b/drivers/virtio/virtio.c
> > @@ -117,6 +117,40 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
> > }
> > EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
> >
> > +static void __virtio_config_changed(struct virtio_device *dev)
> > +{
> > + struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
> > +
> > + if (!dev->config_enabled)
> > + dev->config_changed = true;
> > + else if (drv && drv->config_changed)
> > + drv->config_changed(dev);
> > +}
> > +
> > +void virtio_config_changed(struct virtio_device *dev)
> > +{
> > + spin_lock_irq(&dev->config_lock);
> > + __virtio_config_changed(dev);
> > + spin_unlock_irq(&dev->config_lock);
>
> Hm, isn't this function called from the interrupt handler?
>
Good catch, will fix up, thanks!
> > +}
> > +EXPORT_SYMBOL_GPL(virtio_config_changed);
> > +
> > +static void virtio_config_disable(struct virtio_device *dev)
> > +{
> > + spin_lock_irq(&dev->config_lock);
> > + dev->config_enabled = false;
> > + spin_unlock_irq(&dev->config_lock);
> > +}
> > +
> > +static void virtio_config_enable(struct virtio_device *dev)
> > +{
> > + spin_lock_irq(&dev->config_lock);
> > + dev->config_enabled = true;
> > + __virtio_config_changed(dev);
> > + dev->config_changed = false;
> > + spin_unlock_irq(&dev->config_lock);
> > +}
> > +
>
> Maybe call these virtio_config_change_{dis,en}able()?
>
> > static int virtio_dev_probe(struct device *_d)
> > {
> > int err, i;
next prev parent reply other threads:[~2014-10-06 11:56 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-05 16:06 [PATCH 00/16] virtio: fix spec compliance issues Michael S. Tsirkin
2014-10-05 16:06 ` [PATCH 01/16] virtio_pci: fix virtio spec compliance on restore Michael S. Tsirkin
2014-10-05 16:06 ` [PATCH 02/16] virtio: unify config_changed handling Michael S. Tsirkin
2014-10-06 9:20 ` Cornelia Huck
2014-10-05 16:06 ` [PATCH 03/16] virtio: refactor to use drv_to_virtio Michael S. Tsirkin
2014-10-06 10:34 ` Cornelia Huck
2014-10-05 16:07 ` [PATCH 04/16] virtio-pci: move freeze/restore to virtio core Michael S. Tsirkin
2014-10-06 10:54 ` Cornelia Huck
2014-10-05 16:07 ` [PATCH 05/16] virtio: defer config changed notifications Michael S. Tsirkin
2014-10-06 11:33 ` Cornelia Huck
2014-10-06 12:00 ` Michael S. Tsirkin [this message]
2014-10-05 16:07 ` [PATCH 06/16] virtio_blk: drop config_enable Michael S. Tsirkin
2014-10-06 11:42 ` Cornelia Huck
2014-10-06 12:09 ` Michael S. Tsirkin
2014-10-06 12:20 ` Cornelia Huck
2014-10-06 12:31 ` Michael S. Tsirkin
2014-10-06 12:55 ` Cornelia Huck
2014-10-05 16:07 ` [PATCH 07/16] virtio-blk: drop config_mutex Michael S. Tsirkin
2014-10-06 11:48 ` Cornelia Huck
2014-10-05 16:07 ` [PATCH 08/16] virtio_net: drop config_enable Michael S. Tsirkin
2014-10-06 11:50 ` Cornelia Huck
2014-10-06 12:10 ` Michael S. Tsirkin
2014-10-06 19:02 ` David Miller
2014-10-07 6:49 ` Michael S. Tsirkin
2014-10-07 15:36 ` David Miller
2014-10-07 15:42 ` Michael S. Tsirkin
2014-10-05 16:07 ` [PATCH 09/16] virtio-net: drop config_mutex Michael S. Tsirkin
2014-10-06 11:46 ` Sergei Shtylyov
2014-10-06 11:56 ` Michael S. Tsirkin
2014-10-06 12:07 ` Sergei Shtylyov
2014-10-06 12:22 ` Michael S. Tsirkin
2014-10-06 12:31 ` Sergei Shtylyov
2014-10-06 11:56 ` Cornelia Huck
2014-10-06 12:01 ` Michael S. Tsirkin
2014-10-05 16:07 ` [PATCH 10/16] virtio: add API to enable VQs early Michael S. Tsirkin
2014-10-06 14:08 ` Cornelia Huck
2014-10-06 14:51 ` Michael S. Tsirkin
2014-10-05 16:07 ` [PATCH 11/16] virtio_net: minor cleanup Michael S. Tsirkin
2014-10-06 12:06 ` Cornelia Huck
2014-10-05 16:07 ` [PATCH 12/16] virtio_net: enable VQs early Michael S. Tsirkin
2014-10-05 16:07 ` [PATCH 13/16] virtio_blk: " Michael S. Tsirkin
2014-10-05 16:07 ` [PATCH 14/16] virtio_console: " Michael S. Tsirkin
2014-10-05 16:07 ` [PATCH 15/16] 9p/trans_virtio: " Michael S. Tsirkin
2014-10-05 16:07 ` [PATCH 16/16] virtio_net: fix use after free on allocation failure Michael S. Tsirkin
2014-10-06 14:17 ` Cornelia Huck
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