在 2022/1/26 下午3:35, Xuan Zhuo 写道:
This patch implements virtio pci support for QUEUE RESET.
Performing reset on a queue is divided into two steps:
1. reset_vq: reset one vq
2. enable_reset_vq: re-enable the reset queue
In the first step, these tasks will be completed:
1. notify the hardware queue to reset
2. recycle the buffer from vq
3. release the ring of the vq
The process of enable reset vq:
vp_modern_enable_reset_vq()
vp_enable_reset_vq()
__vp_setup_vq()
setup_vq()
vring_setup_virtqueue()
In this process, we added two parameters, vq and num, and finally passed
them to vring_setup_virtqueue(). And reuse the original info and vq.
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_pci_common.c | 36 +++++++----
drivers/virtio/virtio_pci_common.h | 5 ++
drivers/virtio/virtio_pci_modern.c | 100 +++++++++++++++++++++++++++++
3 files changed, 128 insertions(+), 13 deletions(-)
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index c02936d29a31..ad21638fbf66 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -205,23 +205,28 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
return err;
}
-static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
- void (*callback)(struct virtqueue *vq),
- const char *name,
- bool ctx,
- u16 msix_vec, u16 num)
+struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name,
+ bool ctx,
+ u16 msix_vec, u16 num)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL);
+ struct virtio_pci_vq_info *info;
struct virtqueue *vq;
unsigned long flags;
- /* fill out our structure that represents an active queue */
- if (!info)
- return ERR_PTR(-ENOMEM);
+ info = vp_dev->vqs[index];
+ if (!info) {
+ info = kzalloc(sizeof *info, GFP_KERNEL);
+
+ /* fill out our structure that represents an active queue */
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+ }
vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx,
- msix_vec, NULL, num);
+ msix_vec, info->vq, num);
if (IS_ERR(vq))
goto out_info;
@@ -238,6 +243,9 @@ static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
return vq;
out_info:
+ if (info->vq && info->vq->reset)
+ return vq;
+
kfree(info);
return vq;
}
@@ -248,9 +256,11 @@ 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_common.h b/drivers/virtio/virtio_pci_common.h
index 65db92245e41..c1d15f7c0be4 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -119,6 +119,11 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[], vq_callback_t *callbacks[],
const char * const names[], const bool *ctx,
struct irq_affinity *desc);
+struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name,
+ bool ctx,
+ u16 msix_vec, u16 num);
const char *vp_bus_name(struct virtio_device *vdev);
/* Setup the affinity for a virtqueue:
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 2ce58de549de..6789411169e4 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 +179,94 @@ static void vp_reset(struct virtio_device *vdev)
vp_disable_cbs(vdev);
}
+static int vp_modern_reset_vq(struct virtio_reset_vq *param)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(param->vdev);
+ struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+ struct virtio_pci_vq_info *info;
+ u16 msix_vec, queue_index;
+ unsigned long flags;
+ void *buf;
+
+ if (!virtio_has_feature(param->vdev, VIRTIO_F_RING_RESET))
+ return -ENOENT;
+
+ queue_index = param->queue_index;
+
+ vp_modern_set_queue_reset(mdev, queue_index);
+
+ /* After write 1 to queue reset, the driver MUST wait for a read of
+ * queue reset to return 1.
+ */
+ while (vp_modern_get_queue_reset(mdev, queue_index) != 1)
+ msleep(1);
Is this better to move this logic into vp_modern_set_queue_reset()?
+
+ info = vp_dev->vqs[queue_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));
How about the INTX case where irq is shared? I guess we need to disable
and enable the irq as well.
+
+ while ((buf = virtqueue_detach_unused_buf(info->vq)) != NULL)
+ param->free_unused_cb(param, buf);
Any reason that we can't leave this logic to driver? (Or is there any
operations that must be done before the following operations?)
+
+ /* delete vq */
+ spin_lock_irqsave(&vp_dev->lock, flags);
+ list_del(&info->node);
+ spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+ INIT_LIST_HEAD(&info->node);
+
+ if (vp_dev->msix_enabled)
+ vp_modern_queue_vector(mdev, info->vq->index,
+ VIRTIO_MSI_NO_VECTOR);
I wonder if this is a must.
+
+ if (!mdev->notify_base)
+ pci_iounmap(mdev->pci_dev,
+ (void __force __iomem *)info->vq->priv);
Is this a must? what happens if we simply don't do this?
+
+ vring_reset_virtqueue(info->vq);
+
+ return 0;
+}
+
+static struct virtqueue *vp_modern_enable_reset_vq(struct virtio_reset_vq *param)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(param->vdev);
+ struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+ struct virtio_pci_vq_info *info;
+ u16 msix_vec, queue_index;
+ struct virtqueue *vq;
+
+ if (!virtio_has_feature(param->vdev, VIRTIO_F_RING_RESET))
+ return ERR_PTR(-ENOENT);
+
+ queue_index = param->queue_index;
+
+ info = vp_dev->vqs[queue_index];
+
+ if (!info->vq->reset)
+ return ERR_PTR(-EPERM);
+
+ /* check queue reset status */
+ if (vp_modern_get_queue_reset(mdev, queue_index) != 1)
+ return ERR_PTR(-EBUSY);
+
+ vq = vp_setup_vq(param->vdev, queue_index, param->callback, param->name,
+ param->ctx, info->msix_vector, param->ring_num);
+ if (IS_ERR(vq))
+ return vq;
+
+ vp_modern_set_queue_enable(&vp_dev->mdev, vq->index, true);
+
+ msix_vec = vp_dev->vqs[queue_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));
How about the INT-X case?
Thanks
+
+ return vq;
+}
+
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
{
return vp_modern_config_vector(&vp_dev->mdev, vector);
@@ -284,6 +375,11 @@ static void del_vq(struct virtio_pci_vq_info *info)
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+ if (vq->reset) {
+ vring_del_virtqueue(vq);
+ return;
+ }
+
if (vp_dev->msix_enabled)
vp_modern_queue_vector(mdev, vq->index,
VIRTIO_MSI_NO_VECTOR);
@@ -403,6 +499,8 @@ 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 = {
@@ -421,6 +519,8 @@ 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 */
