Xuan Zhuo
2022-Jan-19 02:35 UTC
[PATCH 5/6] virtio: queue_reset: pci: support VIRTIO_F_RING_RESET
This patch implements virtio pci support for QUEUE RESET.
Performing reset on a queue is divided into three steps:
1. reset_vq: notify the hardware queue to reset
2. del_reset_vq: delete the reset queue
3. enable_reset_vq: re-enable the reset queue
Between steps 1 and 2, generally call virtqueue_detach_unused_buf() to
recycle the buffer.
When deleting a vq, vp_del_vq() will be called to release all the memory
of the vq. But this does not affect the process of deleting vqs, because
that is based on the queue to release all the vqs. During this process,
the vq has been removed from the queue.
When deleting vq, info and vq will be released, and I save msix_vec in
vp_dev->vqs[queue_index]. When re-enable, the current msix_vec can be
reused. And based on intx_enabled to determine which method to use to
enable this queue.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_pci_common.c | 54 ++++++++++++++++++++
drivers/virtio/virtio_pci_common.h | 5 ++
drivers/virtio/virtio_pci_modern.c | 81 ++++++++++++++++++++++++++++++
include/linux/virtio_config.h | 21 ++++++++
4 files changed, 161 insertions(+)
diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index 5afe207ce28a..615a5a5f757c 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -464,6 +464,60 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx);
}
+#define VQ_IS_DELETED(vp_dev, idx) ((unsigned long)vp_dev->vqs[idx] & 1)
+#define VQ_RESET_MSIX_VEC(vp_dev, idx) ((unsigned long)vp_dev->vqs[idx]
>> 2)
+#define VQ_RESET_MARK(msix_vec) ((void *)(long)((msix_vec << 2) + 1))
+
+int vp_del_reset_vq(struct virtio_device *vdev, u16 queue_index)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtio_pci_vq_info *info;
+ u16 msix_vec;
+
+ if (VQ_IS_DELETED(vp_dev, queue_index))
+ return -EPERM;
+
+ info = vp_dev->vqs[queue_index];
+
+ msix_vec = info->msix_vector;
+
+ /* delete vq */
+ vp_del_vq(info->vq);
+
+ /* Mark the vq has been deleted, and save the msix_vec. */
+ vp_dev->vqs[queue_index] = VQ_RESET_MARK(msix_vec);
+
+ return 0;
+}
+
+struct virtqueue *vp_enable_reset_vq(struct virtio_device *vdev,
+ int queue_index,
+ vq_callback_t *callback,
+ const char *name,
+ const bool ctx)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtqueue *vq;
+ u16 msix_vec;
+
+ if (!VQ_IS_DELETED(vp_dev, queue_index))
+ return ERR_PTR(-EPERM);
+
+ msix_vec = VQ_RESET_MSIX_VEC(vp_dev, queue_index);
+
+ if (vp_dev->intx_enabled)
+ vq = vp_setup_vq(vdev, queue_index, callback, name, ctx,
+ VIRTIO_MSI_NO_VECTOR);
+ else
+ vq = vp_enable_vq_msix(vdev, queue_index, callback, name, ctx,
+ msix_vec);
+
+ if (IS_ERR(vq))
+ vp_dev->vqs[queue_index] = VQ_RESET_MARK(msix_vec);
+
+ return vq;
+}
+
const char *vp_bus_name(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
diff --git a/drivers/virtio/virtio_pci_common.h
b/drivers/virtio/virtio_pci_common.h
index 23f6c5c678d5..a92c99cc010e 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -115,6 +115,11 @@ 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);
+void vp_reset_vq(struct virtio_device *vdev, u16 queue_index);
+int vp_del_reset_vq(struct virtio_device *vdev, u16 queue_index);
+struct virtqueue *vp_enable_reset_vq(struct virtio_device *vdev, int
queue_index,
+ vq_callback_t *callback, const char *name,
+ const bool ctx);
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 5455bc041fb6..74e0b2b2f4dc 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 +179,78 @@ static void vp_reset(struct virtio_device *vdev)
vp_disable_cbs(vdev);
}
+static int vp_modern_reset_vq(struct virtio_device *vdev, u16 queue_index)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+ u16 msix_vec;
+
+ if (!virtio_has_feature(vdev, VIRTIO_F_RING_RESET))
+ return -ENOENT;
+
+ 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);
+
+ msix_vec = vp_dev->vqs[queue_index]->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));
+
+ return 0;
+}
+
+static int vp_modern_del_reset_vq(struct virtio_device *vdev, u16 queue_index)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+
+ if (!virtio_has_feature(vdev, VIRTIO_F_RING_RESET))
+ return -ENOENT;
+
+ /* check queue reset status */
+ if (vp_modern_get_queue_reset(mdev, queue_index) != 1)
+ return -EBUSY;
+
+ return vp_del_reset_vq(vdev, queue_index);
+}
+
+static struct virtqueue *vp_modern_enable_reset_vq(struct virtio_device *vdev,
+ u16 queue_index,
+ vq_callback_t *callback,
+ const char *name,
+ const bool *ctx)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+ struct virtqueue *vq;
+ u16 msix_vec;
+
+ if (!virtio_has_feature(vdev, VIRTIO_F_RING_RESET))
+ return ERR_PTR(-ENOENT);
+
+ /* check queue reset status */
+ if (vp_modern_get_queue_reset(mdev, queue_index) != 1)
+ return ERR_PTR(-EBUSY);
+
+ vq = vp_enable_reset_vq(vdev, queue_index, callback, name, ctx);
+ 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));
+
+ return vq;
+}
+
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
{
return vp_modern_config_vector(&vp_dev->mdev, vector);
@@ -395,6 +470,9 @@ 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,
+ .del_reset_vq = vp_modern_del_reset_vq,
+ .enable_reset_vq = vp_modern_enable_reset_vq,
};
static const struct virtio_config_ops virtio_pci_config_ops = {
@@ -413,6 +491,9 @@ 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,
+ .del_reset_vq = vp_modern_del_reset_vq,
+ .enable_reset_vq = vp_modern_enable_reset_vq,
};
/* the PCI probing function */
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 4d107ad31149..6e94f7d0e153 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -74,6 +74,21 @@ struct virtio_shm_region {
* @set_vq_affinity: set the affinity for a virtqueue (optional).
* @get_vq_affinity: get the affinity for a virtqueue (optional).
* @get_shm_region: get a shared memory region based on the index.
+ * @reset_vq: reset a queue individually
+ * vdev: the device
+ * queue_index: the queue index
+ * returns 0 on success or error status
+ * @del_reset_vq: del a reset queue
+ * vdev: the device
+ * queue_index: the queue index
+ * returns 0 on success or error status.
+ * @enable_reset_vq: enable a reset queue
+ * vdev: the device
+ * queue_index: the queue index
+ * callback: callback for the virtqueue, NULL for vq that do not need a
callback
+ * name: virtqueue names (mainly for debugging), NULL for vq unused by driver
+ * ctx: ctx
+ * returns vq on success or error status
*/
typedef void vq_callback_t(struct virtqueue *);
struct virtio_config_ops {
@@ -100,6 +115,12 @@ struct virtio_config_ops {
int index);
bool (*get_shm_region)(struct virtio_device *vdev,
struct virtio_shm_region *region, u8 id);
+ int (*reset_vq)(struct virtio_device *vdev, u16 queue_index);
+ int (*del_reset_vq)(struct virtio_device *vdev, u16 queue_index);
+ struct virtqueue *(*enable_reset_vq)(struct virtio_device *vdev,
+ u16 queue_index,
+ vq_callback_t *callback,
+ const char *name, const bool *ctx);
};
/* If driver didn't advertise the feature, it will never appear. */
--
2.31.0
Jason Wang
2022-Jan-19 06:11 UTC
[PATCH 5/6] virtio: queue_reset: pci: support VIRTIO_F_RING_RESET
On Wed, Jan 19, 2022 at 10:35 AM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > This patch implements virtio pci support for QUEUE RESET. > > Performing reset on a queue is divided into three steps: > > 1. reset_vq: notify the hardware queue to reset > 2. del_reset_vq: delete the reset queue > 3. enable_reset_vq: re-enable the reset queue > > Between steps 1 and 2, generally call virtqueue_detach_unused_buf() to > recycle the buffer.I wonder if it's better to squash 1, 2 and virtqueue_detach_unused_buf() into a single helper.> > When deleting a vq, vp_del_vq() will be called to release all the memory > of the vq. But this does not affect the process of deleting vqs, because > that is based on the queue to release all the vqs. During this process, > the vq has been removed from the queue. > > When deleting vq, info and vq will be released, and I save msix_vec in > vp_dev->vqs[queue_index]. When re-enable, the current msix_vec can be > reused. And based on intx_enabled to determine which method to use to > enable this queue. > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > --- > drivers/virtio/virtio_pci_common.c | 54 ++++++++++++++++++++ > drivers/virtio/virtio_pci_common.h | 5 ++ > drivers/virtio/virtio_pci_modern.c | 81 ++++++++++++++++++++++++++++++ > include/linux/virtio_config.h | 21 ++++++++ > 4 files changed, 161 insertions(+) > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > index 5afe207ce28a..615a5a5f757c 100644 > --- a/drivers/virtio/virtio_pci_common.c > +++ b/drivers/virtio/virtio_pci_common.c > @@ -464,6 +464,60 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs, > return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx); > } > > +#define VQ_IS_DELETED(vp_dev, idx) ((unsigned long)vp_dev->vqs[idx] & 1) > +#define VQ_RESET_MSIX_VEC(vp_dev, idx) ((unsigned long)vp_dev->vqs[idx] >> 2) > +#define VQ_RESET_MARK(msix_vec) ((void *)(long)((msix_vec << 2) + 1)) > + > +int vp_del_reset_vq(struct virtio_device *vdev, u16 queue_index) > +{ > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > + struct virtio_pci_vq_info *info; > + u16 msix_vec; > + > + if (VQ_IS_DELETED(vp_dev, queue_index)) > + return -EPERM; > + > + info = vp_dev->vqs[queue_index]; > + > + msix_vec = info->msix_vector; > + > + /* delete vq */ > + vp_del_vq(info->vq); > + > + /* Mark the vq has been deleted, and save the msix_vec. */ > + vp_dev->vqs[queue_index] = VQ_RESET_MARK(msix_vec); > + > + return 0; > +} > + > +struct virtqueue *vp_enable_reset_vq(struct virtio_device *vdev, > + int queue_index, > + vq_callback_t *callback, > + const char *name, > + const bool ctx) > +{ > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > + struct virtqueue *vq; > + u16 msix_vec; > + > + if (!VQ_IS_DELETED(vp_dev, queue_index)) > + return ERR_PTR(-EPERM); > + > + msix_vec = VQ_RESET_MSIX_VEC(vp_dev, queue_index); > + > + if (vp_dev->intx_enabled) > + vq = vp_setup_vq(vdev, queue_index, callback, name, ctx, > + VIRTIO_MSI_NO_VECTOR); > + else > + vq = vp_enable_vq_msix(vdev, queue_index, callback, name, ctx, > + msix_vec); > + > + if (IS_ERR(vq)) > + vp_dev->vqs[queue_index] = VQ_RESET_MARK(msix_vec); > + > + return vq; > +} > + > const char *vp_bus_name(struct virtio_device *vdev) > { > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h > index 23f6c5c678d5..a92c99cc010e 100644 > --- a/drivers/virtio/virtio_pci_common.h > +++ b/drivers/virtio/virtio_pci_common.h > @@ -115,6 +115,11 @@ 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); > +void vp_reset_vq(struct virtio_device *vdev, u16 queue_index); > +int vp_del_reset_vq(struct virtio_device *vdev, u16 queue_index); > +struct virtqueue *vp_enable_reset_vq(struct virtio_device *vdev, int queue_index, > + vq_callback_t *callback, const char *name, > + const bool ctx); > 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 5455bc041fb6..74e0b2b2f4dc 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 +179,78 @@ static void vp_reset(struct virtio_device *vdev) > vp_disable_cbs(vdev); > } > > +static int vp_modern_reset_vq(struct virtio_device *vdev, u16 queue_index) > +{ > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > + struct virtio_pci_modern_device *mdev = &vp_dev->mdev; > + u16 msix_vec; > + > + if (!virtio_has_feature(vdev, VIRTIO_F_RING_RESET)) > + return -ENOENT; > + > + 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); > + > + msix_vec = vp_dev->vqs[queue_index]->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));What happens if the irq is shared among virtqueues?> + > + return 0; > +} > + > +static int vp_modern_del_reset_vq(struct virtio_device *vdev, u16 queue_index) > +{ > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > + struct virtio_pci_modern_device *mdev = &vp_dev->mdev; > + > + if (!virtio_has_feature(vdev, VIRTIO_F_RING_RESET)) > + return -ENOENT; > + > + /* check queue reset status */ > + if (vp_modern_get_queue_reset(mdev, queue_index) != 1) > + return -EBUSY; > + > + return vp_del_reset_vq(vdev, queue_index); > +} > + > +static struct virtqueue *vp_modern_enable_reset_vq(struct virtio_device *vdev, > + u16 queue_index, > + vq_callback_t *callback, > + const char *name, > + const bool *ctx) > +{ > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > + struct virtio_pci_modern_device *mdev = &vp_dev->mdev; > + struct virtqueue *vq; > + u16 msix_vec; > + > + if (!virtio_has_feature(vdev, VIRTIO_F_RING_RESET)) > + return ERR_PTR(-ENOENT); > + > + /* check queue reset status */ > + if (vp_modern_get_queue_reset(mdev, queue_index) != 1) > + return ERR_PTR(-EBUSY); > + > + vq = vp_enable_reset_vq(vdev, queue_index, callback, name, ctx); > + 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)); > + > + return vq; > +} > + > static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) > { > return vp_modern_config_vector(&vp_dev->mdev, vector); > @@ -395,6 +470,9 @@ 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, > + .del_reset_vq = vp_modern_del_reset_vq, > + .enable_reset_vq = vp_modern_enable_reset_vq, > }; > > static const struct virtio_config_ops virtio_pci_config_ops = { > @@ -413,6 +491,9 @@ 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, > + .del_reset_vq = vp_modern_del_reset_vq, > + .enable_reset_vq = vp_modern_enable_reset_vq, > }; > > /* the PCI probing function */ > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index 4d107ad31149..6e94f7d0e153 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -74,6 +74,21 @@ struct virtio_shm_region { > * @set_vq_affinity: set the affinity for a virtqueue (optional). > * @get_vq_affinity: get the affinity for a virtqueue (optional). > * @get_shm_region: get a shared memory region based on the index. > + * @reset_vq: reset a queue individually > + * vdev: the device > + * queue_index: the queue index > + * returns 0 on success or error status > + * @del_reset_vq: del a reset queue > + * vdev: the device > + * queue_index: the queue index > + * returns 0 on success or error status. > + * @enable_reset_vq: enable a reset queue > + * vdev: the device > + * queue_index: the queue index > + * callback: callback for the virtqueue, NULL for vq that do not need a callback > + * name: virtqueue names (mainly for debugging), NULL for vq unused by driver > + * ctx: ctx > + * returns vq on success or error status > */ > typedef void vq_callback_t(struct virtqueue *); > struct virtio_config_ops { > @@ -100,6 +115,12 @@ struct virtio_config_ops { > int index); > bool (*get_shm_region)(struct virtio_device *vdev, > struct virtio_shm_region *region, u8 id); > + int (*reset_vq)(struct virtio_device *vdev, u16 queue_index); > + int (*del_reset_vq)(struct virtio_device *vdev, u16 queue_index); > + struct virtqueue *(*enable_reset_vq)(struct virtio_device *vdev, > + u16 queue_index, > + vq_callback_t *callback, > + const char *name, const bool *ctx); > }; > > /* If driver didn't advertise the feature, it will never appear. */ > -- > 2.31.0 >