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virtio_net: refactor freeze/restore logic into virtnet reset logic
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For XDP we will need to reset the queues to allow for buffer headroom
to be configured. In order to do this we need to essentially run the
freeze()/restore() code path. Unfortunately the locking requirements
between the freeze/restore and reset paths are different however so
we can not simply reuse the code.

This patch refactors the code path and adds a reset helper routine.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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John Fastabend authored and David S. Miller committed Feb 7, 2017
1 parent 722d828 commit 9fe7bfc
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Showing 3 changed files with 73 additions and 48 deletions.
75 changes: 46 additions & 29 deletions drivers/net/virtio_net.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1661,6 +1661,49 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
.set_settings = virtnet_set_settings,
};

static void virtnet_freeze_down(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
int i;

/* Make sure no work handler is accessing the device */
flush_work(&vi->config_work);

netif_device_detach(vi->dev);
cancel_delayed_work_sync(&vi->refill);

if (netif_running(vi->dev)) {
for (i = 0; i < vi->max_queue_pairs; i++)
napi_disable(&vi->rq[i].napi);
}
}

static int init_vqs(struct virtnet_info *vi);

static int virtnet_restore_up(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
int err, i;

err = init_vqs(vi);
if (err)
return err;

virtio_device_ready(vdev);

if (netif_running(vi->dev)) {
for (i = 0; i < vi->curr_queue_pairs; i++)
if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
schedule_delayed_work(&vi->refill, 0);

for (i = 0; i < vi->max_queue_pairs; i++)
virtnet_napi_enable(&vi->rq[i]);
}

netif_device_attach(vi->dev);
return err;
}

static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog)
{
unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr);
Expand Down Expand Up @@ -2353,21 +2396,9 @@ static void virtnet_remove(struct virtio_device *vdev)
static int virtnet_freeze(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
int i;

virtnet_cpu_notif_remove(vi);

/* Make sure no work handler is accessing the device */
flush_work(&vi->config_work);

netif_device_detach(vi->dev);
cancel_delayed_work_sync(&vi->refill);

if (netif_running(vi->dev)) {
for (i = 0; i < vi->max_queue_pairs; i++)
napi_disable(&vi->rq[i].napi);
}

virtnet_freeze_down(vdev);
remove_vq_common(vi);

return 0;
Expand All @@ -2376,25 +2407,11 @@ static int virtnet_freeze(struct virtio_device *vdev)
static int virtnet_restore(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
int err, i;
int err;

err = init_vqs(vi);
err = virtnet_restore_up(vdev);
if (err)
return err;

virtio_device_ready(vdev);

if (netif_running(vi->dev)) {
for (i = 0; i < vi->curr_queue_pairs; i++)
if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
schedule_delayed_work(&vi->refill, 0);

for (i = 0; i < vi->max_queue_pairs; i++)
virtnet_napi_enable(&vi->rq[i]);
}

netif_device_attach(vi->dev);

virtnet_set_queues(vi, vi->curr_queue_pairs);

err = virtnet_cpu_notif_add(vi);
Expand Down
42 changes: 23 additions & 19 deletions drivers/virtio/virtio.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -100,11 +100,6 @@ static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
dev->id.device, dev->id.vendor);
}

static void add_status(struct virtio_device *dev, unsigned status)
{
dev->config->set_status(dev, dev->config->get_status(dev) | status);
}

void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
unsigned int fbit)
{
Expand Down Expand Up @@ -145,14 +140,15 @@ void virtio_config_changed(struct virtio_device *dev)
}
EXPORT_SYMBOL_GPL(virtio_config_changed);

static void virtio_config_disable(struct virtio_device *dev)
void virtio_config_disable(struct virtio_device *dev)
{
spin_lock_irq(&dev->config_lock);
dev->config_enabled = false;
spin_unlock_irq(&dev->config_lock);
}
EXPORT_SYMBOL_GPL(virtio_config_disable);

static void virtio_config_enable(struct virtio_device *dev)
void virtio_config_enable(struct virtio_device *dev)
{
spin_lock_irq(&dev->config_lock);
dev->config_enabled = true;
Expand All @@ -161,8 +157,15 @@ static void virtio_config_enable(struct virtio_device *dev)
dev->config_change_pending = false;
spin_unlock_irq(&dev->config_lock);
}
EXPORT_SYMBOL_GPL(virtio_config_enable);

void virtio_add_status(struct virtio_device *dev, unsigned int status)
{
dev->config->set_status(dev, dev->config->get_status(dev) | status);
}
EXPORT_SYMBOL_GPL(virtio_add_status);

static int virtio_finalize_features(struct virtio_device *dev)
int virtio_finalize_features(struct virtio_device *dev)
{
int ret = dev->config->finalize_features(dev);
unsigned status;
Expand All @@ -173,7 +176,7 @@ static int virtio_finalize_features(struct virtio_device *dev)
if (!virtio_has_feature(dev, VIRTIO_F_VERSION_1))
return 0;

add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
virtio_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
status = dev->config->get_status(dev);
if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
dev_err(&dev->dev, "virtio: device refuses features: %x\n",
Expand All @@ -182,6 +185,7 @@ static int virtio_finalize_features(struct virtio_device *dev)
}
return 0;
}
EXPORT_SYMBOL_GPL(virtio_finalize_features);

static int virtio_dev_probe(struct device *_d)
{
Expand All @@ -193,7 +197,7 @@ static int virtio_dev_probe(struct device *_d)
u64 driver_features_legacy;

/* We have a driver! */
add_status(dev, VIRTIO_CONFIG_S_DRIVER);
virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);

/* Figure out what features the device supports. */
device_features = dev->config->get_features(dev);
Expand Down Expand Up @@ -247,7 +251,7 @@ static int virtio_dev_probe(struct device *_d)

return 0;
err:
add_status(dev, VIRTIO_CONFIG_S_FAILED);
virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
return err;

}
Expand All @@ -265,7 +269,7 @@ static int virtio_dev_remove(struct device *_d)
WARN_ON_ONCE(dev->config->get_status(dev));

/* Acknowledge the device's existence again. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
return 0;
}

Expand Down Expand Up @@ -316,7 +320,7 @@ int register_virtio_device(struct virtio_device *dev)
dev->config->reset(dev);

/* Acknowledge that we've seen the device. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);

INIT_LIST_HEAD(&dev->vqs);

Expand All @@ -325,7 +329,7 @@ int register_virtio_device(struct virtio_device *dev)
err = device_register(&dev->dev);
out:
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
return err;
}
EXPORT_SYMBOL_GPL(register_virtio_device);
Expand Down Expand Up @@ -365,18 +369,18 @@ int virtio_device_restore(struct virtio_device *dev)
dev->config->reset(dev);

/* Acknowledge that we've seen the device. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);

/* Maybe driver failed before freeze.
* Restore the failed status, for debugging. */
if (dev->failed)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);

if (!drv)
return 0;

/* We have a driver! */
add_status(dev, VIRTIO_CONFIG_S_DRIVER);
virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER);

ret = virtio_finalize_features(dev);
if (ret)
Expand All @@ -389,14 +393,14 @@ int virtio_device_restore(struct virtio_device *dev)
}

/* Finally, tell the device we're all set */
add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);

virtio_config_enable(dev);

return 0;

err:
add_status(dev, VIRTIO_CONFIG_S_FAILED);
virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED);
return ret;
}
EXPORT_SYMBOL_GPL(virtio_device_restore);
Expand Down
4 changes: 4 additions & 0 deletions include/linux/virtio.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -132,12 +132,16 @@ static inline struct virtio_device *dev_to_virtio(struct device *_dev)
return container_of(_dev, struct virtio_device, dev);
}

void virtio_add_status(struct virtio_device *dev, unsigned int status);
int register_virtio_device(struct virtio_device *dev);
void unregister_virtio_device(struct virtio_device *dev);

void virtio_break_device(struct virtio_device *dev);

void virtio_config_changed(struct virtio_device *dev);
void virtio_config_disable(struct virtio_device *dev);
void virtio_config_enable(struct virtio_device *dev);
int virtio_finalize_features(struct virtio_device *dev);
#ifdef CONFIG_PM_SLEEP
int virtio_device_freeze(struct virtio_device *dev);
int virtio_device_restore(struct virtio_device *dev);
Expand Down

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