Re: [PATCH v4 14/14] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET
From: Jason Wang
Date: Fri Feb 11 2022 - 02:05:54 EST
在 2022/2/9 下午8:29, Xuan Zhuo 写道:
This patch implements virtio pci support for QUEUE RESET.
Performing reset on a queue is divided into these steps:
1. reset_vq: reset one vq
2. recycle the buffer from vq by virtqueue_detach_unused_buf()
3. release the ring of the vq by vring_release_virtqueue()
4. enable_reset_vq: re-enable the reset queue
This patch implements reset_vq, enable_reset_vq in the pci scenario
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_pci_common.c | 8 +--
drivers/virtio/virtio_pci_modern.c | 80 ++++++++++++++++++++++++++++--
drivers/virtio/virtio_ring.c | 2 +
include/linux/virtio.h | 1 +
4 files changed, 85 insertions(+), 6 deletions(-)
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index cb01eb0cb2e4..303637ac4914 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -255,9 +255,11 @@ 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 d29d40bf0b45..cc45515eda50 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 */
@@ -176,6 +179,70 @@ static void vp_reset(struct virtio_device *vdev)
vp_disable_cbs(vdev);
}
+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;
+ u16 msix_vec;
+
+ 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];
+ msix_vec = info->msix_vector;
+
+ /* Disable VQ callback. */
+ if (vp_dev->per_vq_vectors && msix_vec != VIRTIO_MSI_NO_VECTOR)
+ disable_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec));
I think we need a comment to explain why per_vq_mode needs to be dealt
with differently.
+
+ /* delete vq */
+ spin_lock_irqsave(&vp_dev->lock, flags);
+ list_del(&info->node);
+ spin_unlock_irqrestore(&vp_dev->lock, flags);
So I don't see where vring is freed and vp_setup_vq() may try to
allocate new memory, won't it be a memory leak in this case?
Thanks
+
+ vq->reset = true;
+
+ INIT_LIST_HEAD(&info->node);
+
+ return 0;
+}
+
+static int vp_modern_enable_reset_vq(struct virtqueue *vq, u16 ring_num)
+{
+ 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;
+ struct virtqueue *_vq;
+ u16 msix_vec;
+
+ if (!vq->reset)
+ return -EPERM;
+
+ /* check queue reset status */
+ if (vp_modern_get_queue_reset(mdev, vq->index) != 1)
+ return -EBUSY;
+
+ info = vp_dev->vqs[vq->index];
+ _vq = vp_setup_vq(vq->vdev, vq->index, NULL, NULL, NULL,
+ info->msix_vector, ring_num);
+ if (IS_ERR(_vq)) {
+ vq->reset = true;
+ return PTR_ERR(_vq);
+ }
+
+ vp_modern_set_queue_enable(&vp_dev->mdev, vq->index, true);
+
+ msix_vec = vp_dev->vqs[vq->index]->msix_vector;
+ if (vp_dev->per_vq_vectors && msix_vec != VIRTIO_MSI_NO_VECTOR)
+ enable_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec));
+
+ return 0;
+}
+
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
{
return vp_modern_config_vector(&vp_dev->mdev, vector);
@@ -231,10 +298,13 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
virtqueue_get_avail_addr(vq),
virtqueue_get_used_addr(vq));
- vq->priv = (void __force *)vp_modern_map_vq_notify(mdev, index, NULL);
if (!vq->priv) {
- err = -ENOMEM;
- goto err_map_notify;
+ vq->priv = (void __force *)vp_modern_map_vq_notify(mdev, index,
+ NULL);
+ if (!vq->priv) {
+ err = -ENOMEM;
+ goto err_map_notify;
+ }
This seems unrelated or an artifact of previous patches?
Thanks
}
if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
@@ -402,6 +472,8 @@ 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 = {
@@ -420,6 +492,8 @@ 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 b8747df8dc1f..4f6028e1e2d9 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1731,6 +1731,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
vq->vq.vdev = vdev;
vq->vq.num_free = num;
vq->vq.index = index;
+ vq->vq.reset = false;
vq->we_own_ring = true;
vq->notify = notify;
vq->weak_barriers = weak_barriers;
@@ -2220,6 +2221,7 @@ static int __vring_init_virtqueue(struct virtqueue *_vq,
vq->vq.vdev = vdev;
vq->vq.num_free = vring.num;
vq->vq.index = index;
+ vq->vq.reset = false;
vq->we_own_ring = false;
vq->notify = notify;
vq->weak_barriers = weak_barriers;
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index dd1657c3a488..5d4817d79f3f 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -32,6 +32,7 @@ struct virtqueue {
unsigned int index;
unsigned int num_free;
void *priv;
+ bool reset;
};
int virtqueue_add_outbuf(struct virtqueue *vq,