Xuan Zhuo
2022-Apr-06 03:43 UTC
[PATCH v9 23/32] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET
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 at 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) {
+ 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,
--
2.31.0
Jason Wang
2022-Apr-12 07:07 UTC
[PATCH v9 23/32] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET
? 2022/4/6 ??11:43, Xuan Zhuo ??:> 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 at 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,