diff mbox series

[v9,23/32] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET

Message ID 20220406034346.74409-24-xuanzhuo@linux.alibaba.com (mailing list archive)
State Not Applicable
Delegated to: Netdev Maintainers
Headers show
Series virtio pci support VIRTIO_F_RING_RESET (refactor vring) | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Xuan Zhuo April 6, 2022, 3:43 a.m. UTC
This patch implements virtio pci support for QUEUE RESET.

Performing reset on a queue is divided into these steps:

 1. notify the device to reset the queue
 2. recycle the buffer submitted
 3. reset the vring (may re-alloc)
 4. mmap vring to device, and enable the queue

This patch implements virtio_reset_vq(), virtio_enable_resetq() in the
pci scenario.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/virtio/virtio_pci_common.c |  8 +--
 drivers/virtio/virtio_pci_modern.c | 84 ++++++++++++++++++++++++++++++
 drivers/virtio/virtio_ring.c       |  2 +
 include/linux/virtio.h             |  1 +
 4 files changed, 92 insertions(+), 3 deletions(-)

Comments

Jason Wang April 12, 2022, 7:07 a.m. UTC | #1
在 2022/4/6 上午11:43, Xuan Zhuo 写道:
> This patch implements virtio pci support for QUEUE RESET.
>
> Performing reset on a queue is divided into these steps:
>
>   1. notify the device to reset the queue
>   2. recycle the buffer submitted
>   3. reset the vring (may re-alloc)
>   4. mmap vring to device, and enable the queue
>
> This patch implements virtio_reset_vq(), virtio_enable_resetq() in the
> pci scenario.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>   drivers/virtio/virtio_pci_common.c |  8 +--
>   drivers/virtio/virtio_pci_modern.c | 84 ++++++++++++++++++++++++++++++
>   drivers/virtio/virtio_ring.c       |  2 +
>   include/linux/virtio.h             |  1 +
>   4 files changed, 92 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
> index fdbde1db5ec5..863d3a8a0956 100644
> --- a/drivers/virtio/virtio_pci_common.c
> +++ b/drivers/virtio/virtio_pci_common.c
> @@ -248,9 +248,11 @@ static void vp_del_vq(struct virtqueue *vq)
>   	struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
>   	unsigned long flags;
>   
> -	spin_lock_irqsave(&vp_dev->lock, flags);
> -	list_del(&info->node);
> -	spin_unlock_irqrestore(&vp_dev->lock, flags);
> +	if (!vq->reset) {


On which condition that we may hit this path?


> +		spin_lock_irqsave(&vp_dev->lock, flags);
> +		list_del(&info->node);
> +		spin_unlock_irqrestore(&vp_dev->lock, flags);
> +	}
>   
>   	vp_dev->del_vq(info);
>   	kfree(info);
> diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
> index 49a4493732cf..cb5d38f1c9c8 100644
> --- a/drivers/virtio/virtio_pci_modern.c
> +++ b/drivers/virtio/virtio_pci_modern.c
> @@ -34,6 +34,9 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features)
>   	if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
>   			pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
>   		__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
> +
> +	if (features & BIT_ULL(VIRTIO_F_RING_RESET))
> +		__virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
>   }
>   
>   /* virtio config->finalize_features() implementation */
> @@ -199,6 +202,83 @@ static int vp_active_vq(struct virtqueue *vq, u16 msix_vec)
>   	return 0;
>   }
>   
> +static int vp_modern_reset_vq(struct virtqueue *vq)
> +{
> +	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> +	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> +	struct virtio_pci_vq_info *info;
> +	unsigned long flags;
> +
> +	if (!virtio_has_feature(vq->vdev, VIRTIO_F_RING_RESET))
> +		return -ENOENT;
> +
> +	vp_modern_set_queue_reset(mdev, vq->index);
> +
> +	info = vp_dev->vqs[vq->index];
> +
> +	/* delete vq from irq handler */
> +	spin_lock_irqsave(&vp_dev->lock, flags);
> +	list_del(&info->node);
> +	spin_unlock_irqrestore(&vp_dev->lock, flags);
> +
> +	INIT_LIST_HEAD(&info->node);
> +
> +	/* For the case where vq has an exclusive irq, to prevent the irq from
> +	 * being received again and the pending irq, call disable_irq().
> +	 *
> +	 * In the scenario based on shared interrupts, vq will be searched from
> +	 * the queue virtqueues. Since the previous list_del() has been deleted
> +	 * from the queue, it is impossible for vq to be called in this case.
> +	 * There is no need to close the corresponding interrupt.
> +	 */
> +	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> +		disable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));


See the previous discussion and the revert of the first try to harden 
the interrupt. We probably can't use disable_irq() since it conflicts 
with the affinity managed IRQ that is used by some drivers.

We need to use synchonize_irq() and per virtqueue flag instead. As 
mentioned in previous patches, this could be done on top of my rework on 
the IRQ hardening .


> +
> +	vq->reset = true;
> +
> +	return 0;
> +}
> +
> +static int vp_modern_enable_reset_vq(struct virtqueue *vq)
> +{
> +	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> +	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> +	struct virtio_pci_vq_info *info;
> +	unsigned long flags, index;
> +	int err;
> +
> +	if (!vq->reset)
> +		return -EBUSY;
> +
> +	index = vq->index;
> +	info = vp_dev->vqs[index];
> +
> +	/* check queue reset status */
> +	if (vp_modern_get_queue_reset(mdev, index) != 1)
> +		return -EBUSY;
> +
> +	err = vp_active_vq(vq, info->msix_vector);
> +	if (err)
> +		return err;
> +
> +	if (vq->callback) {
> +		spin_lock_irqsave(&vp_dev->lock, flags);
> +		list_add(&info->node, &vp_dev->virtqueues);
> +		spin_unlock_irqrestore(&vp_dev->lock, flags);
> +	} else {
> +		INIT_LIST_HEAD(&info->node);
> +	}
> +
> +	vp_modern_set_queue_enable(&vp_dev->mdev, index, true);
> +
> +	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> +		enable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));


We had the same issue as disable_irq().

Thanks


> +
> +	vq->reset = false;
> +
> +	return 0;
> +}
> +
>   static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
>   {
>   	return vp_modern_config_vector(&vp_dev->mdev, vector);
> @@ -407,6 +487,8 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
>   	.set_vq_affinity = vp_set_vq_affinity,
>   	.get_vq_affinity = vp_get_vq_affinity,
>   	.get_shm_region  = vp_get_shm_region,
> +	.reset_vq	 = vp_modern_reset_vq,
> +	.enable_reset_vq = vp_modern_enable_reset_vq,
>   };
>   
>   static const struct virtio_config_ops virtio_pci_config_ops = {
> @@ -425,6 +507,8 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
>   	.set_vq_affinity = vp_set_vq_affinity,
>   	.get_vq_affinity = vp_get_vq_affinity,
>   	.get_shm_region  = vp_get_shm_region,
> +	.reset_vq	 = vp_modern_reset_vq,
> +	.enable_reset_vq = vp_modern_enable_reset_vq,
>   };
>   
>   /* the PCI probing function */
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 6250e19fc5bf..91937e21edca 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -2028,6 +2028,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
>   	vq->vq.vdev = vdev;
>   	vq->vq.name = name;
>   	vq->vq.index = index;
> +	vq->vq.reset = false;
>   	vq->notify = notify;
>   	vq->weak_barriers = weak_barriers;
>   
> @@ -2508,6 +2509,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
>   	vq->vq.vdev = vdev;
>   	vq->vq.name = name;
>   	vq->vq.index = index;
> +	vq->vq.reset = false;
>   	vq->notify = notify;
>   	vq->weak_barriers = weak_barriers;
>   
> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> index c86ff02e0ca0..33ab003c5100 100644
> --- a/include/linux/virtio.h
> +++ b/include/linux/virtio.h
> @@ -33,6 +33,7 @@ struct virtqueue {
>   	unsigned int num_free;
>   	unsigned int num_max;
>   	void *priv;
> +	bool reset;
>   };
>   
>   int virtqueue_add_outbuf(struct virtqueue *vq,
Xuan Zhuo April 13, 2022, 3:21 a.m. UTC | #2
On Tue, 12 Apr 2022 15:07:58 +0800, Jason Wang <jasowang@redhat.com> wrote:
>
> 在 2022/4/6 上午11:43, Xuan Zhuo 写道:
> > This patch implements virtio pci support for QUEUE RESET.
> >
> > Performing reset on a queue is divided into these steps:
> >
> >   1. notify the device to reset the queue
> >   2. recycle the buffer submitted
> >   3. reset the vring (may re-alloc)
> >   4. mmap vring to device, and enable the queue
> >
> > This patch implements virtio_reset_vq(), virtio_enable_resetq() in the
> > pci scenario.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > ---
> >   drivers/virtio/virtio_pci_common.c |  8 +--
> >   drivers/virtio/virtio_pci_modern.c | 84 ++++++++++++++++++++++++++++++
> >   drivers/virtio/virtio_ring.c       |  2 +
> >   include/linux/virtio.h             |  1 +
> >   4 files changed, 92 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
> > index fdbde1db5ec5..863d3a8a0956 100644
> > --- a/drivers/virtio/virtio_pci_common.c
> > +++ b/drivers/virtio/virtio_pci_common.c
> > @@ -248,9 +248,11 @@ static void vp_del_vq(struct virtqueue *vq)
> >   	struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
> >   	unsigned long flags;
> >
> > -	spin_lock_irqsave(&vp_dev->lock, flags);
> > -	list_del(&info->node);
> > -	spin_unlock_irqrestore(&vp_dev->lock, flags);
> > +	if (!vq->reset) {
>
>
> On which condition that we may hit this path?
>
>
> > +		spin_lock_irqsave(&vp_dev->lock, flags);
> > +		list_del(&info->node);
> > +		spin_unlock_irqrestore(&vp_dev->lock, flags);
> > +	}
> >
> >   	vp_dev->del_vq(info);
> >   	kfree(info);
> > diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
> > index 49a4493732cf..cb5d38f1c9c8 100644
> > --- a/drivers/virtio/virtio_pci_modern.c
> > +++ b/drivers/virtio/virtio_pci_modern.c
> > @@ -34,6 +34,9 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features)
> >   	if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
> >   			pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
> >   		__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
> > +
> > +	if (features & BIT_ULL(VIRTIO_F_RING_RESET))
> > +		__virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
> >   }
> >
> >   /* virtio config->finalize_features() implementation */
> > @@ -199,6 +202,83 @@ static int vp_active_vq(struct virtqueue *vq, u16 msix_vec)
> >   	return 0;
> >   }
> >
> > +static int vp_modern_reset_vq(struct virtqueue *vq)
> > +{
> > +	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> > +	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> > +	struct virtio_pci_vq_info *info;
> > +	unsigned long flags;
> > +
> > +	if (!virtio_has_feature(vq->vdev, VIRTIO_F_RING_RESET))
> > +		return -ENOENT;
> > +
> > +	vp_modern_set_queue_reset(mdev, vq->index);
> > +
> > +	info = vp_dev->vqs[vq->index];
> > +
> > +	/* delete vq from irq handler */
> > +	spin_lock_irqsave(&vp_dev->lock, flags);
> > +	list_del(&info->node);
> > +	spin_unlock_irqrestore(&vp_dev->lock, flags);
> > +
> > +	INIT_LIST_HEAD(&info->node);
> > +
> > +	/* For the case where vq has an exclusive irq, to prevent the irq from
> > +	 * being received again and the pending irq, call disable_irq().
> > +	 *
> > +	 * In the scenario based on shared interrupts, vq will be searched from
> > +	 * the queue virtqueues. Since the previous list_del() has been deleted
> > +	 * from the queue, it is impossible for vq to be called in this case.
> > +	 * There is no need to close the corresponding interrupt.
> > +	 */
> > +	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> > +		disable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));
>
>
> See the previous discussion and the revert of the first try to harden
> the interrupt. We probably can't use disable_irq() since it conflicts
> with the affinity managed IRQ that is used by some drivers.
>
> We need to use synchonize_irq() and per virtqueue flag instead. As
> mentioned in previous patches, this could be done on top of my rework on
> the IRQ hardening .

OK, the next version will contain hardened features by per virtqueue flag.

Thanks.

>
>
> > +
> > +	vq->reset = true;
> > +
> > +	return 0;
> > +}
> > +
> > +static int vp_modern_enable_reset_vq(struct virtqueue *vq)
> > +{
> > +	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> > +	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> > +	struct virtio_pci_vq_info *info;
> > +	unsigned long flags, index;
> > +	int err;
> > +
> > +	if (!vq->reset)
> > +		return -EBUSY;
> > +
> > +	index = vq->index;
> > +	info = vp_dev->vqs[index];
> > +
> > +	/* check queue reset status */
> > +	if (vp_modern_get_queue_reset(mdev, index) != 1)
> > +		return -EBUSY;
> > +
> > +	err = vp_active_vq(vq, info->msix_vector);
> > +	if (err)
> > +		return err;
> > +
> > +	if (vq->callback) {
> > +		spin_lock_irqsave(&vp_dev->lock, flags);
> > +		list_add(&info->node, &vp_dev->virtqueues);
> > +		spin_unlock_irqrestore(&vp_dev->lock, flags);
> > +	} else {
> > +		INIT_LIST_HEAD(&info->node);
> > +	}
> > +
> > +	vp_modern_set_queue_enable(&vp_dev->mdev, index, true);
> > +
> > +	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> > +		enable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));
>
>
> We had the same issue as disable_irq().
>
> Thanks
>
>
> > +
> > +	vq->reset = false;
> > +
> > +	return 0;
> > +}
> > +
> >   static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
> >   {
> >   	return vp_modern_config_vector(&vp_dev->mdev, vector);
> > @@ -407,6 +487,8 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
> >   	.set_vq_affinity = vp_set_vq_affinity,
> >   	.get_vq_affinity = vp_get_vq_affinity,
> >   	.get_shm_region  = vp_get_shm_region,
> > +	.reset_vq	 = vp_modern_reset_vq,
> > +	.enable_reset_vq = vp_modern_enable_reset_vq,
> >   };
> >
> >   static const struct virtio_config_ops virtio_pci_config_ops = {
> > @@ -425,6 +507,8 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
> >   	.set_vq_affinity = vp_set_vq_affinity,
> >   	.get_vq_affinity = vp_get_vq_affinity,
> >   	.get_shm_region  = vp_get_shm_region,
> > +	.reset_vq	 = vp_modern_reset_vq,
> > +	.enable_reset_vq = vp_modern_enable_reset_vq,
> >   };
> >
> >   /* the PCI probing function */
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index 6250e19fc5bf..91937e21edca 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -2028,6 +2028,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
> >   	vq->vq.vdev = vdev;
> >   	vq->vq.name = name;
> >   	vq->vq.index = index;
> > +	vq->vq.reset = false;
> >   	vq->notify = notify;
> >   	vq->weak_barriers = weak_barriers;
> >
> > @@ -2508,6 +2509,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
> >   	vq->vq.vdev = vdev;
> >   	vq->vq.name = name;
> >   	vq->vq.index = index;
> > +	vq->vq.reset = false;
> >   	vq->notify = notify;
> >   	vq->weak_barriers = weak_barriers;
> >
> > diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> > index c86ff02e0ca0..33ab003c5100 100644
> > --- a/include/linux/virtio.h
> > +++ b/include/linux/virtio.h
> > @@ -33,6 +33,7 @@ struct virtqueue {
> >   	unsigned int num_free;
> >   	unsigned int num_max;
> >   	void *priv;
> > +	bool reset;
> >   };
> >
> >   int virtqueue_add_outbuf(struct virtqueue *vq,
>
Xuan Zhuo April 13, 2022, 8:48 a.m. UTC | #3
On Tue, 12 Apr 2022 15:07:58 +0800, Jason Wang <jasowang@redhat.com> wrote:
>
> 在 2022/4/6 上午11:43, Xuan Zhuo 写道:
> > This patch implements virtio pci support for QUEUE RESET.
> >
> > Performing reset on a queue is divided into these steps:
> >
> >   1. notify the device to reset the queue
> >   2. recycle the buffer submitted
> >   3. reset the vring (may re-alloc)
> >   4. mmap vring to device, and enable the queue
> >
> > This patch implements virtio_reset_vq(), virtio_enable_resetq() in the
> > pci scenario.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > ---
> >   drivers/virtio/virtio_pci_common.c |  8 +--
> >   drivers/virtio/virtio_pci_modern.c | 84 ++++++++++++++++++++++++++++++
> >   drivers/virtio/virtio_ring.c       |  2 +
> >   include/linux/virtio.h             |  1 +
> >   4 files changed, 92 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
> > index fdbde1db5ec5..863d3a8a0956 100644
> > --- a/drivers/virtio/virtio_pci_common.c
> > +++ b/drivers/virtio/virtio_pci_common.c
> > @@ -248,9 +248,11 @@ static void vp_del_vq(struct virtqueue *vq)
> >   	struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
> >   	unsigned long flags;
> >
> > -	spin_lock_irqsave(&vp_dev->lock, flags);
> > -	list_del(&info->node);
> > -	spin_unlock_irqrestore(&vp_dev->lock, flags);
> > +	if (!vq->reset) {
>
>
> On which condition that we may hit this path?

As discussed in patch 31, it may fail when renable vq.

Thanks.

>
>
> > +		spin_lock_irqsave(&vp_dev->lock, flags);
> > +		list_del(&info->node);
> > +		spin_unlock_irqrestore(&vp_dev->lock, flags);
> > +	}
> >
> >   	vp_dev->del_vq(info);
> >   	kfree(info);
> > diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
> > index 49a4493732cf..cb5d38f1c9c8 100644
> > --- a/drivers/virtio/virtio_pci_modern.c
> > +++ b/drivers/virtio/virtio_pci_modern.c
> > @@ -34,6 +34,9 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features)
> >   	if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
> >   			pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
> >   		__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
> > +
> > +	if (features & BIT_ULL(VIRTIO_F_RING_RESET))
> > +		__virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
> >   }
> >
> >   /* virtio config->finalize_features() implementation */
> > @@ -199,6 +202,83 @@ static int vp_active_vq(struct virtqueue *vq, u16 msix_vec)
> >   	return 0;
> >   }
> >
> > +static int vp_modern_reset_vq(struct virtqueue *vq)
> > +{
> > +	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> > +	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> > +	struct virtio_pci_vq_info *info;
> > +	unsigned long flags;
> > +
> > +	if (!virtio_has_feature(vq->vdev, VIRTIO_F_RING_RESET))
> > +		return -ENOENT;
> > +
> > +	vp_modern_set_queue_reset(mdev, vq->index);
> > +
> > +	info = vp_dev->vqs[vq->index];
> > +
> > +	/* delete vq from irq handler */
> > +	spin_lock_irqsave(&vp_dev->lock, flags);
> > +	list_del(&info->node);
> > +	spin_unlock_irqrestore(&vp_dev->lock, flags);
> > +
> > +	INIT_LIST_HEAD(&info->node);
> > +
> > +	/* For the case where vq has an exclusive irq, to prevent the irq from
> > +	 * being received again and the pending irq, call disable_irq().
> > +	 *
> > +	 * In the scenario based on shared interrupts, vq will be searched from
> > +	 * the queue virtqueues. Since the previous list_del() has been deleted
> > +	 * from the queue, it is impossible for vq to be called in this case.
> > +	 * There is no need to close the corresponding interrupt.
> > +	 */
> > +	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> > +		disable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));
>
>
> See the previous discussion and the revert of the first try to harden
> the interrupt. We probably can't use disable_irq() since it conflicts
> with the affinity managed IRQ that is used by some drivers.
>
> We need to use synchonize_irq() and per virtqueue flag instead. As
> mentioned in previous patches, this could be done on top of my rework on
> the IRQ hardening .
>
>
> > +
> > +	vq->reset = true;
> > +
> > +	return 0;
> > +}
> > +
> > +static int vp_modern_enable_reset_vq(struct virtqueue *vq)
> > +{
> > +	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> > +	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> > +	struct virtio_pci_vq_info *info;
> > +	unsigned long flags, index;
> > +	int err;
> > +
> > +	if (!vq->reset)
> > +		return -EBUSY;
> > +
> > +	index = vq->index;
> > +	info = vp_dev->vqs[index];
> > +
> > +	/* check queue reset status */
> > +	if (vp_modern_get_queue_reset(mdev, index) != 1)
> > +		return -EBUSY;
> > +
> > +	err = vp_active_vq(vq, info->msix_vector);
> > +	if (err)
> > +		return err;
> > +
> > +	if (vq->callback) {
> > +		spin_lock_irqsave(&vp_dev->lock, flags);
> > +		list_add(&info->node, &vp_dev->virtqueues);
> > +		spin_unlock_irqrestore(&vp_dev->lock, flags);
> > +	} else {
> > +		INIT_LIST_HEAD(&info->node);
> > +	}
> > +
> > +	vp_modern_set_queue_enable(&vp_dev->mdev, index, true);
> > +
> > +	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> > +		enable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));
>
>
> We had the same issue as disable_irq().
>
> Thanks
>
>
> > +
> > +	vq->reset = false;
> > +
> > +	return 0;
> > +}
> > +
> >   static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
> >   {
> >   	return vp_modern_config_vector(&vp_dev->mdev, vector);
> > @@ -407,6 +487,8 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
> >   	.set_vq_affinity = vp_set_vq_affinity,
> >   	.get_vq_affinity = vp_get_vq_affinity,
> >   	.get_shm_region  = vp_get_shm_region,
> > +	.reset_vq	 = vp_modern_reset_vq,
> > +	.enable_reset_vq = vp_modern_enable_reset_vq,
> >   };
> >
> >   static const struct virtio_config_ops virtio_pci_config_ops = {
> > @@ -425,6 +507,8 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
> >   	.set_vq_affinity = vp_set_vq_affinity,
> >   	.get_vq_affinity = vp_get_vq_affinity,
> >   	.get_shm_region  = vp_get_shm_region,
> > +	.reset_vq	 = vp_modern_reset_vq,
> > +	.enable_reset_vq = vp_modern_enable_reset_vq,
> >   };
> >
> >   /* the PCI probing function */
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index 6250e19fc5bf..91937e21edca 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -2028,6 +2028,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
> >   	vq->vq.vdev = vdev;
> >   	vq->vq.name = name;
> >   	vq->vq.index = index;
> > +	vq->vq.reset = false;
> >   	vq->notify = notify;
> >   	vq->weak_barriers = weak_barriers;
> >
> > @@ -2508,6 +2509,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
> >   	vq->vq.vdev = vdev;
> >   	vq->vq.name = name;
> >   	vq->vq.index = index;
> > +	vq->vq.reset = false;
> >   	vq->notify = notify;
> >   	vq->weak_barriers = weak_barriers;
> >
> > diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> > index c86ff02e0ca0..33ab003c5100 100644
> > --- a/include/linux/virtio.h
> > +++ b/include/linux/virtio.h
> > @@ -33,6 +33,7 @@ struct virtqueue {
> >   	unsigned int num_free;
> >   	unsigned int num_max;
> >   	void *priv;
> > +	bool reset;
> >   };
> >
> >   int virtqueue_add_outbuf(struct virtqueue *vq,
>
Jason Wang April 14, 2022, 9:17 a.m. UTC | #4
On Wed, Apr 13, 2022 at 11:23 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>
> On Tue, 12 Apr 2022 15:07:58 +0800, Jason Wang <jasowang@redhat.com> wrote:
> >
> > 在 2022/4/6 上午11:43, Xuan Zhuo 写道:
> > > This patch implements virtio pci support for QUEUE RESET.
> > >
> > > Performing reset on a queue is divided into these steps:
> > >
> > >   1. notify the device to reset the queue
> > >   2. recycle the buffer submitted
> > >   3. reset the vring (may re-alloc)
> > >   4. mmap vring to device, and enable the queue
> > >
> > > This patch implements virtio_reset_vq(), virtio_enable_resetq() in the
> > > pci scenario.
> > >
> > > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > > ---
> > >   drivers/virtio/virtio_pci_common.c |  8 +--
> > >   drivers/virtio/virtio_pci_modern.c | 84 ++++++++++++++++++++++++++++++
> > >   drivers/virtio/virtio_ring.c       |  2 +
> > >   include/linux/virtio.h             |  1 +
> > >   4 files changed, 92 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
> > > index fdbde1db5ec5..863d3a8a0956 100644
> > > --- a/drivers/virtio/virtio_pci_common.c
> > > +++ b/drivers/virtio/virtio_pci_common.c
> > > @@ -248,9 +248,11 @@ static void vp_del_vq(struct virtqueue *vq)
> > >     struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
> > >     unsigned long flags;
> > >
> > > -   spin_lock_irqsave(&vp_dev->lock, flags);
> > > -   list_del(&info->node);
> > > -   spin_unlock_irqrestore(&vp_dev->lock, flags);
> > > +   if (!vq->reset) {
> >
> >
> > On which condition that we may hit this path?
> >
> >
> > > +           spin_lock_irqsave(&vp_dev->lock, flags);
> > > +           list_del(&info->node);
> > > +           spin_unlock_irqrestore(&vp_dev->lock, flags);
> > > +   }
> > >
> > >     vp_dev->del_vq(info);
> > >     kfree(info);
> > > diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
> > > index 49a4493732cf..cb5d38f1c9c8 100644
> > > --- a/drivers/virtio/virtio_pci_modern.c
> > > +++ b/drivers/virtio/virtio_pci_modern.c
> > > @@ -34,6 +34,9 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features)
> > >     if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
> > >                     pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
> > >             __virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
> > > +
> > > +   if (features & BIT_ULL(VIRTIO_F_RING_RESET))
> > > +           __virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
> > >   }
> > >
> > >   /* virtio config->finalize_features() implementation */
> > > @@ -199,6 +202,83 @@ static int vp_active_vq(struct virtqueue *vq, u16 msix_vec)
> > >     return 0;
> > >   }
> > >
> > > +static int vp_modern_reset_vq(struct virtqueue *vq)
> > > +{
> > > +   struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> > > +   struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> > > +   struct virtio_pci_vq_info *info;
> > > +   unsigned long flags;
> > > +
> > > +   if (!virtio_has_feature(vq->vdev, VIRTIO_F_RING_RESET))
> > > +           return -ENOENT;
> > > +
> > > +   vp_modern_set_queue_reset(mdev, vq->index);
> > > +
> > > +   info = vp_dev->vqs[vq->index];
> > > +
> > > +   /* delete vq from irq handler */
> > > +   spin_lock_irqsave(&vp_dev->lock, flags);
> > > +   list_del(&info->node);
> > > +   spin_unlock_irqrestore(&vp_dev->lock, flags);
> > > +
> > > +   INIT_LIST_HEAD(&info->node);
> > > +
> > > +   /* For the case where vq has an exclusive irq, to prevent the irq from
> > > +    * being received again and the pending irq, call disable_irq().
> > > +    *
> > > +    * In the scenario based on shared interrupts, vq will be searched from
> > > +    * the queue virtqueues. Since the previous list_del() has been deleted
> > > +    * from the queue, it is impossible for vq to be called in this case.
> > > +    * There is no need to close the corresponding interrupt.
> > > +    */
> > > +   if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> > > +           disable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));
> >
> >
> > See the previous discussion and the revert of the first try to harden
> > the interrupt. We probably can't use disable_irq() since it conflicts
> > with the affinity managed IRQ that is used by some drivers.
> >
> > We need to use synchonize_irq() and per virtqueue flag instead. As
> > mentioned in previous patches, this could be done on top of my rework on
> > the IRQ hardening .
>
> OK, the next version will contain hardened features by per virtqueue flag.

Actually, I'm working on a new version of hardening. I plan to switch
to the virtqueue flag so we will be fine here if we do the resize work
on top.

I will cc you in the new version.

Thanks

>
> Thanks.
>
> >
> >
> > > +
> > > +   vq->reset = true;
> > > +
> > > +   return 0;
> > > +}
> > > +
> > > +static int vp_modern_enable_reset_vq(struct virtqueue *vq)
> > > +{
> > > +   struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> > > +   struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> > > +   struct virtio_pci_vq_info *info;
> > > +   unsigned long flags, index;
> > > +   int err;
> > > +
> > > +   if (!vq->reset)
> > > +           return -EBUSY;
> > > +
> > > +   index = vq->index;
> > > +   info = vp_dev->vqs[index];
> > > +
> > > +   /* check queue reset status */
> > > +   if (vp_modern_get_queue_reset(mdev, index) != 1)
> > > +           return -EBUSY;
> > > +
> > > +   err = vp_active_vq(vq, info->msix_vector);
> > > +   if (err)
> > > +           return err;
> > > +
> > > +   if (vq->callback) {
> > > +           spin_lock_irqsave(&vp_dev->lock, flags);
> > > +           list_add(&info->node, &vp_dev->virtqueues);
> > > +           spin_unlock_irqrestore(&vp_dev->lock, flags);
> > > +   } else {
> > > +           INIT_LIST_HEAD(&info->node);
> > > +   }
> > > +
> > > +   vp_modern_set_queue_enable(&vp_dev->mdev, index, true);
> > > +
> > > +   if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> > > +           enable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));
> >
> >
> > We had the same issue as disable_irq().
> >
> > Thanks
> >
> >
> > > +
> > > +   vq->reset = false;
> > > +
> > > +   return 0;
> > > +}
> > > +
> > >   static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
> > >   {
> > >     return vp_modern_config_vector(&vp_dev->mdev, vector);
> > > @@ -407,6 +487,8 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
> > >     .set_vq_affinity = vp_set_vq_affinity,
> > >     .get_vq_affinity = vp_get_vq_affinity,
> > >     .get_shm_region  = vp_get_shm_region,
> > > +   .reset_vq        = vp_modern_reset_vq,
> > > +   .enable_reset_vq = vp_modern_enable_reset_vq,
> > >   };
> > >
> > >   static const struct virtio_config_ops virtio_pci_config_ops = {
> > > @@ -425,6 +507,8 @@ static const struct virtio_config_ops virtio_pci_config_ops = {
> > >     .set_vq_affinity = vp_set_vq_affinity,
> > >     .get_vq_affinity = vp_get_vq_affinity,
> > >     .get_shm_region  = vp_get_shm_region,
> > > +   .reset_vq        = vp_modern_reset_vq,
> > > +   .enable_reset_vq = vp_modern_enable_reset_vq,
> > >   };
> > >
> > >   /* the PCI probing function */
> > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > > index 6250e19fc5bf..91937e21edca 100644
> > > --- a/drivers/virtio/virtio_ring.c
> > > +++ b/drivers/virtio/virtio_ring.c
> > > @@ -2028,6 +2028,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
> > >     vq->vq.vdev = vdev;
> > >     vq->vq.name = name;
> > >     vq->vq.index = index;
> > > +   vq->vq.reset = false;
> > >     vq->notify = notify;
> > >     vq->weak_barriers = weak_barriers;
> > >
> > > @@ -2508,6 +2509,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
> > >     vq->vq.vdev = vdev;
> > >     vq->vq.name = name;
> > >     vq->vq.index = index;
> > > +   vq->vq.reset = false;
> > >     vq->notify = notify;
> > >     vq->weak_barriers = weak_barriers;
> > >
> > > diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> > > index c86ff02e0ca0..33ab003c5100 100644
> > > --- a/include/linux/virtio.h
> > > +++ b/include/linux/virtio.h
> > > @@ -33,6 +33,7 @@ struct virtqueue {
> > >     unsigned int num_free;
> > >     unsigned int num_max;
> > >     void *priv;
> > > +   bool reset;
> > >   };
> > >
> > >   int virtqueue_add_outbuf(struct virtqueue *vq,
> >
>
diff mbox series

Patch

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index fdbde1db5ec5..863d3a8a0956 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -248,9 +248,11 @@  static void vp_del_vq(struct virtqueue *vq)
 	struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
 	unsigned long flags;
 
-	spin_lock_irqsave(&vp_dev->lock, flags);
-	list_del(&info->node);
-	spin_unlock_irqrestore(&vp_dev->lock, flags);
+	if (!vq->reset) {
+		spin_lock_irqsave(&vp_dev->lock, flags);
+		list_del(&info->node);
+		spin_unlock_irqrestore(&vp_dev->lock, flags);
+	}
 
 	vp_dev->del_vq(info);
 	kfree(info);
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 49a4493732cf..cb5d38f1c9c8 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -34,6 +34,9 @@  static void vp_transport_features(struct virtio_device *vdev, u64 features)
 	if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
 			pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
 		__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
+
+	if (features & BIT_ULL(VIRTIO_F_RING_RESET))
+		__virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
 }
 
 /* virtio config->finalize_features() implementation */
@@ -199,6 +202,83 @@  static int vp_active_vq(struct virtqueue *vq, u16 msix_vec)
 	return 0;
 }
 
+static int vp_modern_reset_vq(struct virtqueue *vq)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+	struct virtio_pci_vq_info *info;
+	unsigned long flags;
+
+	if (!virtio_has_feature(vq->vdev, VIRTIO_F_RING_RESET))
+		return -ENOENT;
+
+	vp_modern_set_queue_reset(mdev, vq->index);
+
+	info = vp_dev->vqs[vq->index];
+
+	/* delete vq from irq handler */
+	spin_lock_irqsave(&vp_dev->lock, flags);
+	list_del(&info->node);
+	spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+	INIT_LIST_HEAD(&info->node);
+
+	/* For the case where vq has an exclusive irq, to prevent the irq from
+	 * being received again and the pending irq, call disable_irq().
+	 *
+	 * In the scenario based on shared interrupts, vq will be searched from
+	 * the queue virtqueues. Since the previous list_del() has been deleted
+	 * from the queue, it is impossible for vq to be called in this case.
+	 * There is no need to close the corresponding interrupt.
+	 */
+	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
+		disable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));
+
+	vq->reset = true;
+
+	return 0;
+}
+
+static int vp_modern_enable_reset_vq(struct virtqueue *vq)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+	struct virtio_pci_vq_info *info;
+	unsigned long flags, index;
+	int err;
+
+	if (!vq->reset)
+		return -EBUSY;
+
+	index = vq->index;
+	info = vp_dev->vqs[index];
+
+	/* check queue reset status */
+	if (vp_modern_get_queue_reset(mdev, index) != 1)
+		return -EBUSY;
+
+	err = vp_active_vq(vq, info->msix_vector);
+	if (err)
+		return err;
+
+	if (vq->callback) {
+		spin_lock_irqsave(&vp_dev->lock, flags);
+		list_add(&info->node, &vp_dev->virtqueues);
+		spin_unlock_irqrestore(&vp_dev->lock, flags);
+	} else {
+		INIT_LIST_HEAD(&info->node);
+	}
+
+	vp_modern_set_queue_enable(&vp_dev->mdev, index, true);
+
+	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
+		enable_irq(pci_irq_vector(vp_dev->pci_dev, info->msix_vector));
+
+	vq->reset = false;
+
+	return 0;
+}
+
 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
 {
 	return vp_modern_config_vector(&vp_dev->mdev, vector);
@@ -407,6 +487,8 @@  static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
 	.set_vq_affinity = vp_set_vq_affinity,
 	.get_vq_affinity = vp_get_vq_affinity,
 	.get_shm_region  = vp_get_shm_region,
+	.reset_vq	 = vp_modern_reset_vq,
+	.enable_reset_vq = vp_modern_enable_reset_vq,
 };
 
 static const struct virtio_config_ops virtio_pci_config_ops = {
@@ -425,6 +507,8 @@  static const struct virtio_config_ops virtio_pci_config_ops = {
 	.set_vq_affinity = vp_set_vq_affinity,
 	.get_vq_affinity = vp_get_vq_affinity,
 	.get_shm_region  = vp_get_shm_region,
+	.reset_vq	 = vp_modern_reset_vq,
+	.enable_reset_vq = vp_modern_enable_reset_vq,
 };
 
 /* the PCI probing function */
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 6250e19fc5bf..91937e21edca 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2028,6 +2028,7 @@  static struct virtqueue *vring_create_virtqueue_packed(
 	vq->vq.vdev = vdev;
 	vq->vq.name = name;
 	vq->vq.index = index;
+	vq->vq.reset = false;
 	vq->notify = notify;
 	vq->weak_barriers = weak_barriers;
 
@@ -2508,6 +2509,7 @@  struct virtqueue *__vring_new_virtqueue(unsigned int index,
 	vq->vq.vdev = vdev;
 	vq->vq.name = name;
 	vq->vq.index = index;
+	vq->vq.reset = false;
 	vq->notify = notify;
 	vq->weak_barriers = weak_barriers;
 
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index c86ff02e0ca0..33ab003c5100 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -33,6 +33,7 @@  struct virtqueue {
 	unsigned int num_free;
 	unsigned int num_max;
 	void *priv;
+	bool reset;
 };
 
 int virtqueue_add_outbuf(struct virtqueue *vq,