Michael S. Tsirkin
2023-Oct-29 20:22 UTC
[PATCH V2 vfio 2/9] virtio-pci: Introduce admin virtqueue
On Sun, Oct 29, 2023 at 05:59:45PM +0200, Yishai Hadas wrote:> From: Feng Liu <feliu at nvidia.com> > > Introduce support for the admin virtqueue. By negotiating > VIRTIO_F_ADMIN_VQ feature, driver detects capability and creates one > administration virtqueue. Administration virtqueue implementation in > virtio pci generic layer, enables multiple types of upper layer > drivers such as vfio, net, blk to utilize it. > > Signed-off-by: Feng Liu <feliu at nvidia.com> > Reviewed-by: Parav Pandit <parav at nvidia.com> > Reviewed-by: Jiri Pirko <jiri at nvidia.com> > Signed-off-by: Yishai Hadas <yishaih at nvidia.com> > --- > drivers/virtio/virtio.c | 37 ++++++++++++++-- > drivers/virtio/virtio_pci_common.c | 3 ++ > drivers/virtio/virtio_pci_common.h | 15 ++++++- > drivers/virtio/virtio_pci_modern.c | 61 +++++++++++++++++++++++++- > drivers/virtio/virtio_pci_modern_dev.c | 18 ++++++++ > include/linux/virtio_config.h | 4 ++ > include/linux/virtio_pci_modern.h | 5 +++ > 7 files changed, 137 insertions(+), 6 deletions(-) > > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c > index 3893dc29eb26..f4080692b351 100644 > --- a/drivers/virtio/virtio.c > +++ b/drivers/virtio/virtio.c > @@ -302,9 +302,15 @@ static int virtio_dev_probe(struct device *_d) > if (err) > goto err; > > + if (dev->config->create_avq) { > + err = dev->config->create_avq(dev); > + if (err) > + goto err; > + } > + > err = drv->probe(dev); > if (err) > - goto err; > + goto err_probe; > > /* If probe didn't do it, mark device DRIVER_OK ourselves. */ > if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK))Hmm I am not all that happy that we are just creating avq unconditionally. Can't we do it on demand to avoid wasting resources if no one uses it?> @@ -316,6 +322,10 @@ static int virtio_dev_probe(struct device *_d) > virtio_config_enable(dev); > > return 0; > + > +err_probe: > + if (dev->config->destroy_avq) > + dev->config->destroy_avq(dev); > err: > virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); > return err; > @@ -331,6 +341,9 @@ static void virtio_dev_remove(struct device *_d) > > drv->remove(dev); > > + if (dev->config->destroy_avq) > + dev->config->destroy_avq(dev); > + > /* Driver should have reset device. */ > WARN_ON_ONCE(dev->config->get_status(dev)); > > @@ -489,13 +502,20 @@ EXPORT_SYMBOL_GPL(unregister_virtio_device); > int virtio_device_freeze(struct virtio_device *dev) > { > struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); > + int ret; > > virtio_config_disable(dev); > > dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED; > > - if (drv && drv->freeze) > - return drv->freeze(dev); > + if (drv && drv->freeze) { > + ret = drv->freeze(dev); > + if (ret) > + return ret; > + } > + > + if (dev->config->destroy_avq) > + dev->config->destroy_avq(dev); > > return 0; > } > @@ -532,10 +552,16 @@ int virtio_device_restore(struct virtio_device *dev) > if (ret) > goto err; > > + if (dev->config->create_avq) { > + ret = dev->config->create_avq(dev); > + if (ret) > + goto err; > + } > + > if (drv->restore) { > ret = drv->restore(dev); > if (ret) > - goto err; > + goto err_restore; > } > > /* If restore didn't do it, mark device DRIVER_OK ourselves. */ > @@ -546,6 +572,9 @@ int virtio_device_restore(struct virtio_device *dev) > > return 0; > > +err_restore: > + if (dev->config->destroy_avq) > + dev->config->destroy_avq(dev); > err: > virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); > return ret; > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > index c2524a7207cf..6b4766d5abe6 100644 > --- a/drivers/virtio/virtio_pci_common.c > +++ b/drivers/virtio/virtio_pci_common.c > @@ -236,6 +236,9 @@ void vp_del_vqs(struct virtio_device *vdev) > int i; > > list_for_each_entry_safe(vq, n, &vdev->vqs, list) { > + if (vp_dev->is_avq(vdev, vq->index)) > + continue; > + > if (vp_dev->per_vq_vectors) { > int v = vp_dev->vqs[vq->index]->msix_vector; > > diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h > index 4b773bd7c58c..e03af0966a4b 100644 > --- a/drivers/virtio/virtio_pci_common.h > +++ b/drivers/virtio/virtio_pci_common.h > @@ -41,6 +41,14 @@ struct virtio_pci_vq_info { > unsigned int msix_vector; > }; > > +struct virtio_pci_admin_vq { > + /* Virtqueue info associated with this admin queue. */ > + struct virtio_pci_vq_info info; > + /* Name of the admin queue: avq.$index. */ > + char name[10]; > + u16 vq_index; > +}; > + > /* Our device structure */ > struct virtio_pci_device { > struct virtio_device vdev; > @@ -58,9 +66,13 @@ struct virtio_pci_device { > spinlock_t lock; > struct list_head virtqueues; > > - /* array of all queues for house-keeping */ > + /* Array of all virtqueues reported in the > + * PCI common config num_queues field > + */ > struct virtio_pci_vq_info **vqs; > > + struct virtio_pci_admin_vq admin_vq; > + > /* MSI-X support */ > int msix_enabled; > int intx_enabled; > @@ -86,6 +98,7 @@ struct virtio_pci_device { > void (*del_vq)(struct virtio_pci_vq_info *info); > > u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector); > + bool (*is_avq)(struct virtio_device *vdev, unsigned int index); > }; > > /* Constants for MSI-X */ > diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c > index d6bb68ba84e5..01c5ba346471 100644 > --- a/drivers/virtio/virtio_pci_modern.c > +++ b/drivers/virtio/virtio_pci_modern.c > @@ -26,6 +26,16 @@ static u64 vp_get_features(struct virtio_device *vdev) > return vp_modern_get_features(&vp_dev->mdev); > } > > +static bool vp_is_avq(struct virtio_device *vdev, unsigned int index) > +{ > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > + > + if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) > + return false; > + > + return index == vp_dev->admin_vq.vq_index; > +} > + > static void vp_transport_features(struct virtio_device *vdev, u64 features) > { > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > @@ -37,6 +47,9 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features) > > if (features & BIT_ULL(VIRTIO_F_RING_RESET)) > __virtio_set_bit(vdev, VIRTIO_F_RING_RESET); > + > + if (features & BIT_ULL(VIRTIO_F_ADMIN_VQ)) > + __virtio_set_bit(vdev, VIRTIO_F_ADMIN_VQ); > } > > /* virtio config->finalize_features() implementation */ > @@ -317,7 +330,8 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, > else > notify = vp_notify; > > - if (index >= vp_modern_get_num_queues(mdev)) > + if (index >= vp_modern_get_num_queues(mdev) && > + !vp_is_avq(&vp_dev->vdev, index)) > return ERR_PTR(-EINVAL); > > /* Check if queue is either not available or already active. */ > @@ -491,6 +505,46 @@ static bool vp_get_shm_region(struct virtio_device *vdev, > return true; > } > > +static int vp_modern_create_avq(struct virtio_device *vdev) > +{ > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > + struct virtio_pci_admin_vq *avq; > + struct virtqueue *vq; > + u16 admin_q_num; > + > + if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) > + return 0; > + > + admin_q_num = vp_modern_avq_num(&vp_dev->mdev); > + if (!admin_q_num) > + return -EINVAL;We really just need 1 entry ATM. Limit to that?> + > + avq = &vp_dev->admin_vq; > + avq->vq_index = vp_modern_avq_index(&vp_dev->mdev); > + sprintf(avq->name, "avq.%u", avq->vq_index); > + vq = vp_dev->setup_vq(vp_dev, &vp_dev->admin_vq.info, avq->vq_index, NULL, > + avq->name, NULL, VIRTIO_MSI_NO_VECTOR); > + if (IS_ERR(vq)) { > + dev_err(&vdev->dev, "failed to setup admin virtqueue, err=%ld", > + PTR_ERR(vq)); > + return PTR_ERR(vq); > + } > + > + vp_dev->admin_vq.info.vq = vq; > + vp_modern_set_queue_enable(&vp_dev->mdev, avq->info.vq->index, true); > + return 0; > +} > + > +static void vp_modern_destroy_avq(struct virtio_device *vdev) > +{ > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > + > + if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) > + return; > + > + vp_dev->del_vq(&vp_dev->admin_vq.info); > +} > + > static const struct virtio_config_ops virtio_pci_config_nodev_ops = { > .get = NULL, > .set = NULL, > @@ -509,6 +563,8 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = { > .get_shm_region = vp_get_shm_region, > .disable_vq_and_reset = vp_modern_disable_vq_and_reset, > .enable_vq_after_reset = vp_modern_enable_vq_after_reset, > + .create_avq = vp_modern_create_avq, > + .destroy_avq = vp_modern_destroy_avq, > }; > > static const struct virtio_config_ops virtio_pci_config_ops = { > @@ -529,6 +585,8 @@ static const struct virtio_config_ops virtio_pci_config_ops = { > .get_shm_region = vp_get_shm_region, > .disable_vq_and_reset = vp_modern_disable_vq_and_reset, > .enable_vq_after_reset = vp_modern_enable_vq_after_reset, > + .create_avq = vp_modern_create_avq, > + .destroy_avq = vp_modern_destroy_avq, > }; > > /* the PCI probing function */ > @@ -552,6 +610,7 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev) > vp_dev->config_vector = vp_config_vector; > vp_dev->setup_vq = setup_vq; > vp_dev->del_vq = del_vq; > + vp_dev->is_avq = vp_is_avq; > vp_dev->isr = mdev->isr; > vp_dev->vdev.id = mdev->id; > > diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c > index 9cb601e16688..4aab1727d121 100644 > --- a/drivers/virtio/virtio_pci_modern_dev.c > +++ b/drivers/virtio/virtio_pci_modern_dev.c > @@ -714,6 +714,24 @@ void __iomem *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev, > } > EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify); > > +u16 vp_modern_avq_num(struct virtio_pci_modern_device *mdev) > +{ > + struct virtio_pci_modern_common_cfg __iomem *cfg; > + > + cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common; > + return vp_ioread16(&cfg->admin_queue_num); > +} > +EXPORT_SYMBOL_GPL(vp_modern_avq_num); > + > +u16 vp_modern_avq_index(struct virtio_pci_modern_device *mdev) > +{ > + struct virtio_pci_modern_common_cfg __iomem *cfg; > + > + cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common; > + return vp_ioread16(&cfg->admin_queue_index); > +} > +EXPORT_SYMBOL_GPL(vp_modern_avq_index); > + > MODULE_VERSION("0.1"); > MODULE_DESCRIPTION("Modern Virtio PCI Device"); > MODULE_AUTHOR("Jason Wang <jasowang at redhat.com>"); > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index 2b3438de2c4d..da9b271b54db 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -93,6 +93,8 @@ typedef void vq_callback_t(struct virtqueue *); > * Returns 0 on success or error status > * If disable_vq_and_reset is set, then enable_vq_after_reset must also be > * set. > + * @create_avq: create admin virtqueue resource. > + * @destroy_avq: destroy admin virtqueue resource. > */ > struct virtio_config_ops { > void (*get)(struct virtio_device *vdev, unsigned offset, > @@ -120,6 +122,8 @@ struct virtio_config_ops { > struct virtio_shm_region *region, u8 id); > int (*disable_vq_and_reset)(struct virtqueue *vq); > int (*enable_vq_after_reset)(struct virtqueue *vq); > + int (*create_avq)(struct virtio_device *vdev); > + void (*destroy_avq)(struct virtio_device *vdev); > }; > > /* If driver didn't advertise the feature, it will never appear. */ > diff --git a/include/linux/virtio_pci_modern.h b/include/linux/virtio_pci_modern.h > index 067ac1d789bc..0f8737c9ae7d 100644 > --- a/include/linux/virtio_pci_modern.h > +++ b/include/linux/virtio_pci_modern.h > @@ -10,6 +10,9 @@ struct virtio_pci_modern_common_cfg { > > __le16 queue_notify_data; /* read-write */ > __le16 queue_reset; /* read-write */ > + > + __le16 admin_queue_index; /* read-only */ > + __le16 admin_queue_num; /* read-only */ > }; > > struct virtio_pci_modern_device { > @@ -121,4 +124,6 @@ int vp_modern_probe(struct virtio_pci_modern_device *mdev); > void vp_modern_remove(struct virtio_pci_modern_device *mdev); > int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index); > void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index); > +u16 vp_modern_avq_num(struct virtio_pci_modern_device *mdev); > +u16 vp_modern_avq_index(struct virtio_pci_modern_device *mdev); > #endif > -- > 2.27.0
Parav Pandit
2023-Oct-30 15:51 UTC
[PATCH V2 vfio 2/9] virtio-pci: Introduce admin virtqueue
> From: Michael S. Tsirkin <mst at redhat.com> > Sent: Monday, October 30, 2023 1:53 AM > > On Sun, Oct 29, 2023 at 05:59:45PM +0200, Yishai Hadas wrote: > > From: Feng Liu <feliu at nvidia.com> > > > > Introduce support for the admin virtqueue. By negotiating > > VIRTIO_F_ADMIN_VQ feature, driver detects capability and creates one > > administration virtqueue. Administration virtqueue implementation in > > virtio pci generic layer, enables multiple types of upper layer > > drivers such as vfio, net, blk to utilize it. > > > > Signed-off-by: Feng Liu <feliu at nvidia.com> > > Reviewed-by: Parav Pandit <parav at nvidia.com> > > Reviewed-by: Jiri Pirko <jiri at nvidia.com> > > Signed-off-by: Yishai Hadas <yishaih at nvidia.com> > > --- > > drivers/virtio/virtio.c | 37 ++++++++++++++-- > > drivers/virtio/virtio_pci_common.c | 3 ++ > > drivers/virtio/virtio_pci_common.h | 15 ++++++- > > drivers/virtio/virtio_pci_modern.c | 61 +++++++++++++++++++++++++- > > drivers/virtio/virtio_pci_modern_dev.c | 18 ++++++++ > > include/linux/virtio_config.h | 4 ++ > > include/linux/virtio_pci_modern.h | 5 +++ > > 7 files changed, 137 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index > > 3893dc29eb26..f4080692b351 100644 > > --- a/drivers/virtio/virtio.c > > +++ b/drivers/virtio/virtio.c > > @@ -302,9 +302,15 @@ static int virtio_dev_probe(struct device *_d) > > if (err) > > goto err; > > > > + if (dev->config->create_avq) { > > + err = dev->config->create_avq(dev); > > + if (err) > > + goto err; > > + } > > + > > err = drv->probe(dev); > > if (err) > > - goto err; > > + goto err_probe; > > > > /* If probe didn't do it, mark device DRIVER_OK ourselves. */ > > if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK)) > > Hmm I am not all that happy that we are just creating avq unconditionally. > Can't we do it on demand to avoid wasting resources if no one uses it? >Virtio queues must be enabled before driver_ok as we discussed in F_DYNAMIC bit exercise. So creating AQ when first legacy command is invoked, would be too late.> > > @@ -316,6 +322,10 @@ static int virtio_dev_probe(struct device *_d) > > virtio_config_enable(dev); > > > > return 0; > > + > > +err_probe: > > + if (dev->config->destroy_avq) > > + dev->config->destroy_avq(dev); > > err: > > virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); > > return err; > > @@ -331,6 +341,9 @@ static void virtio_dev_remove(struct device *_d) > > > > drv->remove(dev); > > > > + if (dev->config->destroy_avq) > > + dev->config->destroy_avq(dev); > > + > > /* Driver should have reset device. */ > > WARN_ON_ONCE(dev->config->get_status(dev)); > > > > @@ -489,13 +502,20 @@ EXPORT_SYMBOL_GPL(unregister_virtio_device); > > int virtio_device_freeze(struct virtio_device *dev) { > > struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); > > + int ret; > > > > virtio_config_disable(dev); > > > > dev->failed = dev->config->get_status(dev) & > VIRTIO_CONFIG_S_FAILED; > > > > - if (drv && drv->freeze) > > - return drv->freeze(dev); > > + if (drv && drv->freeze) { > > + ret = drv->freeze(dev); > > + if (ret) > > + return ret; > > + } > > + > > + if (dev->config->destroy_avq) > > + dev->config->destroy_avq(dev); > > > > return 0; > > } > > @@ -532,10 +552,16 @@ int virtio_device_restore(struct virtio_device *dev) > > if (ret) > > goto err; > > > > + if (dev->config->create_avq) { > > + ret = dev->config->create_avq(dev); > > + if (ret) > > + goto err; > > + } > > + > > if (drv->restore) { > > ret = drv->restore(dev); > > if (ret) > > - goto err; > > + goto err_restore; > > } > > > > /* If restore didn't do it, mark device DRIVER_OK ourselves. */ @@ > > -546,6 +572,9 @@ int virtio_device_restore(struct virtio_device *dev) > > > > return 0; > > > > +err_restore: > > + if (dev->config->destroy_avq) > > + dev->config->destroy_avq(dev); > > err: > > virtio_add_status(dev, VIRTIO_CONFIG_S_FAILED); > > return ret; > > diff --git a/drivers/virtio/virtio_pci_common.c > > b/drivers/virtio/virtio_pci_common.c > > index c2524a7207cf..6b4766d5abe6 100644 > > --- a/drivers/virtio/virtio_pci_common.c > > +++ b/drivers/virtio/virtio_pci_common.c > > @@ -236,6 +236,9 @@ void vp_del_vqs(struct virtio_device *vdev) > > int i; > > > > list_for_each_entry_safe(vq, n, &vdev->vqs, list) { > > + if (vp_dev->is_avq(vdev, vq->index)) > > + continue; > > + > > if (vp_dev->per_vq_vectors) { > > int v = vp_dev->vqs[vq->index]->msix_vector; > > > > diff --git a/drivers/virtio/virtio_pci_common.h > > b/drivers/virtio/virtio_pci_common.h > > index 4b773bd7c58c..e03af0966a4b 100644 > > --- a/drivers/virtio/virtio_pci_common.h > > +++ b/drivers/virtio/virtio_pci_common.h > > @@ -41,6 +41,14 @@ struct virtio_pci_vq_info { > > unsigned int msix_vector; > > }; > > > > +struct virtio_pci_admin_vq { > > + /* Virtqueue info associated with this admin queue. */ > > + struct virtio_pci_vq_info info; > > + /* Name of the admin queue: avq.$index. */ > > + char name[10]; > > + u16 vq_index; > > +}; > > + > > /* Our device structure */ > > struct virtio_pci_device { > > struct virtio_device vdev; > > @@ -58,9 +66,13 @@ struct virtio_pci_device { > > spinlock_t lock; > > struct list_head virtqueues; > > > > - /* array of all queues for house-keeping */ > > + /* Array of all virtqueues reported in the > > + * PCI common config num_queues field > > + */ > > struct virtio_pci_vq_info **vqs; > > > > + struct virtio_pci_admin_vq admin_vq; > > + > > /* MSI-X support */ > > int msix_enabled; > > int intx_enabled; > > @@ -86,6 +98,7 @@ struct virtio_pci_device { > > void (*del_vq)(struct virtio_pci_vq_info *info); > > > > u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector); > > + bool (*is_avq)(struct virtio_device *vdev, unsigned int index); > > }; > > > > /* Constants for MSI-X */ > > diff --git a/drivers/virtio/virtio_pci_modern.c > > b/drivers/virtio/virtio_pci_modern.c > > index d6bb68ba84e5..01c5ba346471 100644 > > --- a/drivers/virtio/virtio_pci_modern.c > > +++ b/drivers/virtio/virtio_pci_modern.c > > @@ -26,6 +26,16 @@ static u64 vp_get_features(struct virtio_device *vdev) > > return vp_modern_get_features(&vp_dev->mdev); > > } > > > > +static bool vp_is_avq(struct virtio_device *vdev, unsigned int index) > > +{ > > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > > + > > + if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) > > + return false; > > + > > + return index == vp_dev->admin_vq.vq_index; } > > + > > static void vp_transport_features(struct virtio_device *vdev, u64 > > features) { > > struct virtio_pci_device *vp_dev = to_vp_device(vdev); @@ -37,6 > > +47,9 @@ static void vp_transport_features(struct virtio_device *vdev, > > u64 features) > > > > if (features & BIT_ULL(VIRTIO_F_RING_RESET)) > > __virtio_set_bit(vdev, VIRTIO_F_RING_RESET); > > + > > + if (features & BIT_ULL(VIRTIO_F_ADMIN_VQ)) > > + __virtio_set_bit(vdev, VIRTIO_F_ADMIN_VQ); > > } > > > > /* virtio config->finalize_features() implementation */ @@ -317,7 > > +330,8 @@ static struct virtqueue *setup_vq(struct virtio_pci_device > *vp_dev, > > else > > notify = vp_notify; > > > > - if (index >= vp_modern_get_num_queues(mdev)) > > + if (index >= vp_modern_get_num_queues(mdev) && > > + !vp_is_avq(&vp_dev->vdev, index)) > > return ERR_PTR(-EINVAL); > > > > /* Check if queue is either not available or already active. */ @@ > > -491,6 +505,46 @@ static bool vp_get_shm_region(struct virtio_device > *vdev, > > return true; > > } > > > > +static int vp_modern_create_avq(struct virtio_device *vdev) { > > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > > + struct virtio_pci_admin_vq *avq; > > + struct virtqueue *vq; > > + u16 admin_q_num; > > + > > + if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) > > + return 0; > > + > > + admin_q_num = vp_modern_avq_num(&vp_dev->mdev); > > + if (!admin_q_num) > > + return -EINVAL; > > > We really just need 1 entry ATM. Limit to that? >Above check is only reading and validating that number of admin queues being nonzero from the device. It is ok if its > 1. Driver currently using only 1 aq of default depth (entries) reported by the device. Did I misunderstand your question about 1 entry?> > + > > + avq = &vp_dev->admin_vq; > > + avq->vq_index = vp_modern_avq_index(&vp_dev->mdev); > > + sprintf(avq->name, "avq.%u", avq->vq_index); > > + vq = vp_dev->setup_vq(vp_dev, &vp_dev->admin_vq.info, avq- > >vq_index, NULL, > > + avq->name, NULL, VIRTIO_MSI_NO_VECTOR); > > + if (IS_ERR(vq)) { > > + dev_err(&vdev->dev, "failed to setup admin virtqueue, > err=%ld", > > + PTR_ERR(vq)); > > + return PTR_ERR(vq); > > + } > > + > > + vp_dev->admin_vq.info.vq = vq; > > + vp_modern_set_queue_enable(&vp_dev->mdev, avq->info.vq->index, > true); > > + return 0; > > +} > > + > > +static void vp_modern_destroy_avq(struct virtio_device *vdev) { > > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > > + > > + if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ)) > > + return; > > + > > + vp_dev->del_vq(&vp_dev->admin_vq.info); > > +} > > + > > static const struct virtio_config_ops virtio_pci_config_nodev_ops = { > > .get = NULL, > > .set = NULL, > > @@ -509,6 +563,8 @@ static const struct virtio_config_ops > virtio_pci_config_nodev_ops = { > > .get_shm_region = vp_get_shm_region, > > .disable_vq_and_reset = vp_modern_disable_vq_and_reset, > > .enable_vq_after_reset = vp_modern_enable_vq_after_reset, > > + .create_avq = vp_modern_create_avq, > > + .destroy_avq = vp_modern_destroy_avq, > > }; > > > > static const struct virtio_config_ops virtio_pci_config_ops = { @@ > > -529,6 +585,8 @@ static const struct virtio_config_ops virtio_pci_config_ops > = { > > .get_shm_region = vp_get_shm_region, > > .disable_vq_and_reset = vp_modern_disable_vq_and_reset, > > .enable_vq_after_reset = vp_modern_enable_vq_after_reset, > > + .create_avq = vp_modern_create_avq, > > + .destroy_avq = vp_modern_destroy_avq, > > }; > > > > /* the PCI probing function */ > > @@ -552,6 +610,7 @@ int virtio_pci_modern_probe(struct virtio_pci_device > *vp_dev) > > vp_dev->config_vector = vp_config_vector; > > vp_dev->setup_vq = setup_vq; > > vp_dev->del_vq = del_vq; > > + vp_dev->is_avq = vp_is_avq; > > vp_dev->isr = mdev->isr; > > vp_dev->vdev.id = mdev->id; > > > > diff --git a/drivers/virtio/virtio_pci_modern_dev.c > > b/drivers/virtio/virtio_pci_modern_dev.c > > index 9cb601e16688..4aab1727d121 100644 > > --- a/drivers/virtio/virtio_pci_modern_dev.c > > +++ b/drivers/virtio/virtio_pci_modern_dev.c > > @@ -714,6 +714,24 @@ void __iomem *vp_modern_map_vq_notify(struct > > virtio_pci_modern_device *mdev, } > > EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify); > > > > +u16 vp_modern_avq_num(struct virtio_pci_modern_device *mdev) { > > + struct virtio_pci_modern_common_cfg __iomem *cfg; > > + > > + cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev- > >common; > > + return vp_ioread16(&cfg->admin_queue_num); > > +} > > +EXPORT_SYMBOL_GPL(vp_modern_avq_num); > > + > > +u16 vp_modern_avq_index(struct virtio_pci_modern_device *mdev) { > > + struct virtio_pci_modern_common_cfg __iomem *cfg; > > + > > + cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev- > >common; > > + return vp_ioread16(&cfg->admin_queue_index); > > +} > > +EXPORT_SYMBOL_GPL(vp_modern_avq_index); > > + > > MODULE_VERSION("0.1"); > > MODULE_DESCRIPTION("Modern Virtio PCI Device"); > MODULE_AUTHOR("Jason > > Wang <jasowang at redhat.com>"); diff --git > > a/include/linux/virtio_config.h b/include/linux/virtio_config.h index > > 2b3438de2c4d..da9b271b54db 100644 > > --- a/include/linux/virtio_config.h > > +++ b/include/linux/virtio_config.h > > @@ -93,6 +93,8 @@ typedef void vq_callback_t(struct virtqueue *); > > * Returns 0 on success or error status > > * If disable_vq_and_reset is set, then enable_vq_after_reset must also be > > * set. > > + * @create_avq: create admin virtqueue resource. > > + * @destroy_avq: destroy admin virtqueue resource. > > */ > > struct virtio_config_ops { > > void (*get)(struct virtio_device *vdev, unsigned offset, @@ -120,6 > > +122,8 @@ struct virtio_config_ops { > > struct virtio_shm_region *region, u8 id); > > int (*disable_vq_and_reset)(struct virtqueue *vq); > > int (*enable_vq_after_reset)(struct virtqueue *vq); > > + int (*create_avq)(struct virtio_device *vdev); > > + void (*destroy_avq)(struct virtio_device *vdev); > > }; > > > > /* If driver didn't advertise the feature, it will never appear. */ > > diff --git a/include/linux/virtio_pci_modern.h > > b/include/linux/virtio_pci_modern.h > > index 067ac1d789bc..0f8737c9ae7d 100644 > > --- a/include/linux/virtio_pci_modern.h > > +++ b/include/linux/virtio_pci_modern.h > > @@ -10,6 +10,9 @@ struct virtio_pci_modern_common_cfg { > > > > __le16 queue_notify_data; /* read-write */ > > __le16 queue_reset; /* read-write */ > > + > > + __le16 admin_queue_index; /* read-only */ > > + __le16 admin_queue_num; /* read-only */ > > }; > > > > struct virtio_pci_modern_device { > > @@ -121,4 +124,6 @@ int vp_modern_probe(struct > > virtio_pci_modern_device *mdev); void vp_modern_remove(struct > > virtio_pci_modern_device *mdev); int vp_modern_get_queue_reset(struct > > virtio_pci_modern_device *mdev, u16 index); void > > vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 > > index); > > +u16 vp_modern_avq_num(struct virtio_pci_modern_device *mdev); > > +u16 vp_modern_avq_index(struct virtio_pci_modern_device *mdev); > > #endif > > -- > > 2.27.0