diff mbox series

[v12,30/40] virtio_pci: support VIRTIO_F_RING_RESET

Message ID 20220720030436.79520-31-xuanzhuo@linux.alibaba.com (mailing list archive)
State New, archived
Headers show
Series virtio pci support VIRTIO_F_RING_RESET | expand

Commit Message

Xuan Zhuo July 20, 2022, 3:04 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 | 12 +++-
 drivers/virtio/virtio_pci_modern.c | 96 ++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+), 3 deletions(-)

Comments

Jason Wang July 21, 2022, 9:15 a.m. UTC | #1 
在 2022/7/20 11:04, 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 | 12 +++-
>   drivers/virtio/virtio_pci_modern.c | 96 ++++++++++++++++++++++++++++++
>   2 files changed, 105 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
> index ca51fcc9daab..ad258a9d3b9f 100644
> --- a/drivers/virtio/virtio_pci_common.c
> +++ b/drivers/virtio/virtio_pci_common.c
> @@ -214,9 +214,15 @@ 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 it fails during re-enable reset vq. This way we won't rejoin
> +	 * info->node to the queue. Prevent unexpected irqs.
> +	 */
> +	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 9041d9a41b7d..4d28b6918c80 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 +202,95 @@ 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 synchronize_irq(), and
> +	 * break it.
> +	 *
> +	 * We can't use disable_irq() since it conflicts with the affinity
> +	 * managed IRQ that is used by some drivers. So this is done on top of
> +	 * IRQ hardening.
> +	 *
> +	 * 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) {
> +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
> +		__virtqueue_break(vq);
> +#endif


I think we should do this unconditionally since it's an independent 
feature, though the list_del() above should be sufficient.


> +		synchronize_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];
> +
> +	if (vp_modern_get_queue_reset(mdev, index))
> +		return -EBUSY;
> +
> +	if (vp_modern_get_queue_enable(mdev, index))
> +		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);
> +	}
> +
> +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
> +	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> +		__virtqueue_unbreak(vq);
> +#endif
> +
> +	vp_modern_set_queue_enable(&vp_dev->mdev, index, true);
> +	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);
> @@ -413,6 +505,8 @@ 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,
> +	.disable_vq_and_reset = vp_modern_reset_vq,
> +	.enable_vq_after_reset = vp_modern_enable_reset_vq,


Nit:

To be consistent, let's use vp_modern_disable_vq_and_reset() and 
vp_modern_enable_vq_after_reset()

Thanks


>   };
>   
>   static const struct virtio_config_ops virtio_pci_config_ops = {
> @@ -431,6 +525,8 @@ 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,
> +	.disable_vq_and_reset = vp_modern_reset_vq,
> +	.enable_vq_after_reset = vp_modern_enable_reset_vq,
>   };
>   
>   /* the PCI probing function */
Xuan Zhuo July 22, 2022, 3:05 a.m. UTC | #2 
On Thu, 21 Jul 2022 17:15:11 +0800, Jason Wang <jasowang@redhat.com> wrote:
>
> 在 2022/7/20 11:04, 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 | 12 +++-
> >   drivers/virtio/virtio_pci_modern.c | 96 ++++++++++++++++++++++++++++++
> >   2 files changed, 105 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
> > index ca51fcc9daab..ad258a9d3b9f 100644
> > --- a/drivers/virtio/virtio_pci_common.c
> > +++ b/drivers/virtio/virtio_pci_common.c
> > @@ -214,9 +214,15 @@ 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 it fails during re-enable reset vq. This way we won't rejoin
> > +	 * info->node to the queue. Prevent unexpected irqs.
> > +	 */
> > +	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 9041d9a41b7d..4d28b6918c80 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 +202,95 @@ 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 synchronize_irq(), and
> > +	 * break it.
> > +	 *
> > +	 * We can't use disable_irq() since it conflicts with the affinity
> > +	 * managed IRQ that is used by some drivers. So this is done on top of
> > +	 * IRQ hardening.
> > +	 *
> > +	 * 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) {
> > +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
> > +		__virtqueue_break(vq);
> > +#endif
>
>
> I think we should do this unconditionally since it's an independent
> feature, though the list_del() above should be sufficient.

Yes.

>
>
> > +		synchronize_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];
> > +
> > +	if (vp_modern_get_queue_reset(mdev, index))
> > +		return -EBUSY;
> > +
> > +	if (vp_modern_get_queue_enable(mdev, index))
> > +		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);
> > +	}
> > +
> > +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
> > +	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> > +		__virtqueue_unbreak(vq);
> > +#endif
> > +
> > +	vp_modern_set_queue_enable(&vp_dev->mdev, index, true);
> > +	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);
> > @@ -413,6 +505,8 @@ 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,
> > +	.disable_vq_and_reset = vp_modern_reset_vq,
> > +	.enable_vq_after_reset = vp_modern_enable_reset_vq,
>
>
> Nit:
>
> To be consistent, let's use vp_modern_disable_vq_and_reset() and
> vp_modern_enable_vq_after_reset()

Will fix.

Thanks.


>
> Thanks
>
>
> >   };
> >
> >   static const struct virtio_config_ops virtio_pci_config_ops = {
> > @@ -431,6 +525,8 @@ 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,
> > +	.disable_vq_and_reset = vp_modern_reset_vq,
> > +	.enable_vq_after_reset = vp_modern_enable_reset_vq,
> >   };
> >
> >   /* the PCI probing function */
>
diff mbox series

Patch

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index ca51fcc9daab..ad258a9d3b9f 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -214,9 +214,15 @@  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 it fails during re-enable reset vq. This way we won't rejoin
+	 * info->node to the queue. Prevent unexpected irqs.
+	 */
+	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 9041d9a41b7d..4d28b6918c80 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 +202,95 @@  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 synchronize_irq(), and
+	 * break it.
+	 *
+	 * We can't use disable_irq() since it conflicts with the affinity
+	 * managed IRQ that is used by some drivers. So this is done on top of
+	 * IRQ hardening.
+	 *
+	 * 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) {
+#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
+		__virtqueue_break(vq);
+#endif
+		synchronize_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];
+
+	if (vp_modern_get_queue_reset(mdev, index))
+		return -EBUSY;
+
+	if (vp_modern_get_queue_enable(mdev, index))
+		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);
+	}
+
+#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
+	if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
+		__virtqueue_unbreak(vq);
+#endif
+
+	vp_modern_set_queue_enable(&vp_dev->mdev, index, true);
+	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);
@@ -413,6 +505,8 @@  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,
+	.disable_vq_and_reset = vp_modern_reset_vq,
+	.enable_vq_after_reset = vp_modern_enable_reset_vq,
 };
 
 static const struct virtio_config_ops virtio_pci_config_ops = {
@@ -431,6 +525,8 @@  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,
+	.disable_vq_and_reset = vp_modern_reset_vq,
+	.enable_vq_after_reset = vp_modern_enable_reset_vq,
 };
 
 /* the PCI probing function */