Michael S. Tsirkin
2022-Jan-21 15:28 UTC
[PATCH v2 07/12] virtio: queue_reset: pci: support VIRTIO_F_RING_RESET
On Fri, Jan 21, 2022 at 10:09:31PM +0800, Xuan Zhuo wrote:> On Fri, 21 Jan 2022 08:19:55 -0500, Michael S. Tsirkin <mst at redhat.com> wrote: > > On Fri, Jan 21, 2022 at 06:26:33PM +0800, Xuan Zhuo wrote: > > > On Fri, 21 Jan 2022 05:22:59 -0500, Michael S. Tsirkin <mst at redhat.com> wrote: > > > > On Fri, Jan 21, 2022 at 05:22:29AM -0500, Michael S. Tsirkin wrote: > > > > > On Fri, Jan 21, 2022 at 10:22:59AM +0800, Xuan Zhuo wrote: > > > > > > On Thu, 20 Jan 2022 10:03:45 -0500, Michael S. Tsirkin <mst at redhat.com> wrote: > > > > > > > On Thu, Jan 20, 2022 at 07:46:20PM +0800, Xuan Zhuo wrote: > > > > > > > > On Thu, 20 Jan 2022 05:55:14 -0500, Michael S. Tsirkin <mst at redhat.com> wrote: > > > > > > > > > On Thu, Jan 20, 2022 at 02:42:58PM +0800, Xuan Zhuo wrote: > > > > > > > > > > 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. delete the vq > > > > > > > > > > > > > > > > > > > > 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> > > > > > > > > > > > > > > > > > > There's something I don't understand here. It looks like > > > > > > > > > you assume that when you reset a queue, you also > > > > > > > > > reset the mapping from queue to event vector. > > > > > > > > > The spec does not say it should, and I don't think it's > > > > > > > > > useful to extend spec to do it - we already have a simple > > > > > > > > > way to tweak the mapping. > > > > > > > > > > > > > > > > > > > > > > > > > Sorry, what is the already existing method you are referring to, I didn't find > > > > > > > > it. > > > > > > > > > > > > > > > > > > > > > Write 0xffff into vector number. > > > > > > > > > > > > I wonder if there is some misunderstanding here. > > > > > > > > > > > > My purpose is to release vq, then for the vector used by vq, I hope that it can > > > > > > be reused when re-enable. > > > > > > > > > > > > But the vector number is not in a fixed order. When I re-enable it, I don't know > > > > > > what the original vector number is. So I found a place to save this number. > > > > > > > > > > > > The queue reset I implemented is divided into the following steps: > > > > > > 1. notify the driver to queue reset > > > > > > 2. disable_irq() > > > > > > 3. free unused bufs > > > > > > 4. free irq, free vq, free info > > > > > > > > step 4 here seems pointless. > > > > > > > > > The core operation is to release the vq. The release of the irq is indeed by the > > > way. We can leave the irq untouched. > > > > > > 1. notify the driver to queue reset > > > 2. disable_irq() > > > 3. free unused bufs > > > 4. free vq, free info > > > > > > Thanks. > > > > OK. why free the vq and info though? > > > I guess what you mean may be that we do not release the memory of vq, but > reinitialize it and map it to the backend. In this way, the ring size of vq is > also unchanged. > > +After the queue has been successfully reset, the driver MAY release any > +resource associated with that virtqueue. > > [...] > > + > +\devicenormative{\paragraph}{Virtqueue Re-enable}{Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset / Virtqueue Re-enable} > + > +The device MUST observe any queue configuration that may have been > +changed by the driver, like the maximum queue size. > + > +\drivernormative{\paragraph}{Virtqueue Re-enable}{Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset / Virtqueue Re-enable} > + > +When re-enabling a queue, the driver MUST configure the queue resources > +as during initial virtqueue discovery, but optionally with different > +parameters. > + > > Based on the above spec definition, reset can modify, for example, the length of > the queue. So I chose to release memory here. Of course, I have not yet > supported the modification of ring size. > > I wonder if we can provide two methods when implementing queue reset: > > 1. Lightweight reset, do not release vq memory, re-initialize vq. Then > map to the backend (virtio-net supports AF_XDP, this can be satisfied) > 2. Release vq to support modification of ring size. (virtio-net can > modify ring size based on this) > > Thanks.I'm not sure I understand completely. I guess the simpler the reset code the better so ... 1 is simpler I guess?> > > > > > > > > > > > > > The process of enable is divided into the following steps: > > > > > > 1. Get the vector number used by the original vq and re-setup vq > > > > > > 2. enable vq > > > > > > 3. enable irq > > > > > > > > > > > > If there is anything unreasonable please let me know. > > > > > > > > > > > > Thanks. > > > > > > > > > > Why do you free irq? > > > > > > > > > > > > > > > > > > > > I think you mean that we don't have to reset the event vector, I think you are > > > > > > > > right. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > > Avoid doing that, and things will be much easier, with no need > > > > > > > > > to interact with a transport, won't they? > > > > > > > > > > > > > > > > > > > > > > > > > > > > --- > > > > > > > > > > drivers/virtio/virtio_pci_common.c | 49 ++++++++++++++++++++ > > > > > > > > > > drivers/virtio/virtio_pci_common.h | 4 ++ > > > > > > > > > > drivers/virtio/virtio_pci_modern.c | 73 ++++++++++++++++++++++++++++++ > > > > > > > > > > 3 files changed, 126 insertions(+) > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > > > > > > > > > > index 5afe207ce28a..28b5ffde4621 100644 > > > > > > > > > > --- a/drivers/virtio/virtio_pci_common.c > > > > > > > > > > +++ b/drivers/virtio/virtio_pci_common.c > > > > > > > > > > @@ -464,6 +464,55 @@ 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)) > > > > > > > > > > + > > > > > > > > > > +void 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; > > > > > > > > > > + > > > > > > > > > > + 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); > > > > > > > > > > +} > > > > > > > > > > + > > > > > > > > > > +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..96c13b1398f8 100644 > > > > > > > > > > --- a/drivers/virtio/virtio_pci_common.h > > > > > > > > > > +++ b/drivers/virtio/virtio_pci_common.h > > > > > > > > > > @@ -115,6 +115,10 @@ 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_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..fbf87239c920 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 +179,72 @@ 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, > > > > > > > > > > + vq_reset_callback_t *callback, void *data) > > > > > > > > > > +{ > > > > > > > > > > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > > > > > > > > > > + struct virtio_pci_modern_device *mdev = &vp_dev->mdev; > > > > > > > > > > + struct virtio_pci_vq_info *info; > > > > > > > > > > + u16 msix_vec; > > > > > > > > > > + void *buf; > > > > > > > > > > + > > > > > > > > > > + 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); > > > > > > > > > > + > > > > > > > > > > + 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)); > > > > > > > > > > + > > > > > > > > > > + while ((buf = virtqueue_detach_unused_buf(info->vq)) != NULL) > > > > > > > > > > + callback(vdev, buf, data); > > > > > > > > > > + > > > > > > > > > > + vp_del_reset_vq(vdev, queue_index); > > > > > > > > > > + > > > > > > > > > > + return 0; > > > > > > > > > > +} > > > > > > > > > > + > > > > > > > > > > +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 +464,8 @@ 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 = { > > > > > > > > > > @@ -413,6 +484,8 @@ 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 */ > > > > > > > > > > -- > > > > > > > > > > 2.31.0 > > > > > > > > > > > > > > > > > > > > > >
Xuan Zhuo
2022-Jan-21 15:34 UTC
[PATCH v2 07/12] virtio: queue_reset: pci: support VIRTIO_F_RING_RESET
On Fri, 21 Jan 2022 10:28:43 -0500, Michael S. Tsirkin <mst at redhat.com> wrote:> On Fri, Jan 21, 2022 at 10:09:31PM +0800, Xuan Zhuo wrote: > > On Fri, 21 Jan 2022 08:19:55 -0500, Michael S. Tsirkin <mst at redhat.com> wrote: > > > On Fri, Jan 21, 2022 at 06:26:33PM +0800, Xuan Zhuo wrote: > > > > On Fri, 21 Jan 2022 05:22:59 -0500, Michael S. Tsirkin <mst at redhat.com> wrote: > > > > > On Fri, Jan 21, 2022 at 05:22:29AM -0500, Michael S. Tsirkin wrote: > > > > > > On Fri, Jan 21, 2022 at 10:22:59AM +0800, Xuan Zhuo wrote: > > > > > > > On Thu, 20 Jan 2022 10:03:45 -0500, Michael S. Tsirkin <mst at redhat.com> wrote: > > > > > > > > On Thu, Jan 20, 2022 at 07:46:20PM +0800, Xuan Zhuo wrote: > > > > > > > > > On Thu, 20 Jan 2022 05:55:14 -0500, Michael S. Tsirkin <mst at redhat.com> wrote: > > > > > > > > > > On Thu, Jan 20, 2022 at 02:42:58PM +0800, Xuan Zhuo wrote: > > > > > > > > > > > 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. delete the vq > > > > > > > > > > > > > > > > > > > > > > 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> > > > > > > > > > > > > > > > > > > > > There's something I don't understand here. It looks like > > > > > > > > > > you assume that when you reset a queue, you also > > > > > > > > > > reset the mapping from queue to event vector. > > > > > > > > > > The spec does not say it should, and I don't think it's > > > > > > > > > > useful to extend spec to do it - we already have a simple > > > > > > > > > > way to tweak the mapping. > > > > > > > > > > > > > > > > > > > > > > > > > > > > Sorry, what is the already existing method you are referring to, I didn't find > > > > > > > > > it. > > > > > > > > > > > > > > > > > > > > > > > > Write 0xffff into vector number. > > > > > > > > > > > > > > I wonder if there is some misunderstanding here. > > > > > > > > > > > > > > My purpose is to release vq, then for the vector used by vq, I hope that it can > > > > > > > be reused when re-enable. > > > > > > > > > > > > > > But the vector number is not in a fixed order. When I re-enable it, I don't know > > > > > > > what the original vector number is. So I found a place to save this number. > > > > > > > > > > > > > > The queue reset I implemented is divided into the following steps: > > > > > > > 1. notify the driver to queue reset > > > > > > > 2. disable_irq() > > > > > > > 3. free unused bufs > > > > > > > 4. free irq, free vq, free info > > > > > > > > > > step 4 here seems pointless. > > > > > > > > > > > > The core operation is to release the vq. The release of the irq is indeed by the > > > > way. We can leave the irq untouched. > > > > > > > > 1. notify the driver to queue reset > > > > 2. disable_irq() > > > > 3. free unused bufs > > > > 4. free vq, free info > > > > > > > > Thanks. > > > > > > OK. why free the vq and info though? > > > > > > I guess what you mean may be that we do not release the memory of vq, but > > reinitialize it and map it to the backend. In this way, the ring size of vq is > > also unchanged. > > > > +After the queue has been successfully reset, the driver MAY release any > > +resource associated with that virtqueue. > > > > [...] > > > > + > > +\devicenormative{\paragraph}{Virtqueue Re-enable}{Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset / Virtqueue Re-enable} > > + > > +The device MUST observe any queue configuration that may have been > > +changed by the driver, like the maximum queue size. > > + > > +\drivernormative{\paragraph}{Virtqueue Re-enable}{Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset / Virtqueue Re-enable} > > + > > +When re-enabling a queue, the driver MUST configure the queue resources > > +as during initial virtqueue discovery, but optionally with different > > +parameters. > > + > > > > Based on the above spec definition, reset can modify, for example, the length of > > the queue. So I chose to release memory here. Of course, I have not yet > > supported the modification of ring size. > > > > I wonder if we can provide two methods when implementing queue reset: > > > > 1. Lightweight reset, do not release vq memory, re-initialize vq. Then > > map to the backend (virtio-net supports AF_XDP, this can be satisfied) > > 2. Release vq to support modification of ring size. (virtio-net can > > modify ring size based on this) > > > > Thanks. > > I'm not sure I understand completely. I guess the simpler the > reset code the better so ... 1 is simpler I guess?Yes. I will first implement the next version based on 1. If there is a need to modify the ring size in the future, we will consider implementing solution 2. Thanks.> > > > > > > > > > > > > > > > > > > > The process of enable is divided into the following steps: > > > > > > > 1. Get the vector number used by the original vq and re-setup vq > > > > > > > 2. enable vq > > > > > > > 3. enable irq > > > > > > > > > > > > > > If there is anything unreasonable please let me know. > > > > > > > > > > > > > > Thanks. > > > > > > > > > > > > Why do you free irq? > > > > > > > > > > > > > > > > > > > > > > > I think you mean that we don't have to reset the event vector, I think you are > > > > > > > > > right. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > > > > Avoid doing that, and things will be much easier, with no need > > > > > > > > > > to interact with a transport, won't they? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > --- > > > > > > > > > > > drivers/virtio/virtio_pci_common.c | 49 ++++++++++++++++++++ > > > > > > > > > > > drivers/virtio/virtio_pci_common.h | 4 ++ > > > > > > > > > > > drivers/virtio/virtio_pci_modern.c | 73 ++++++++++++++++++++++++++++++ > > > > > > > > > > > 3 files changed, 126 insertions(+) > > > > > > > > > > > > > > > > > > > > > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > > > > > > > > > > > index 5afe207ce28a..28b5ffde4621 100644 > > > > > > > > > > > --- a/drivers/virtio/virtio_pci_common.c > > > > > > > > > > > +++ b/drivers/virtio/virtio_pci_common.c > > > > > > > > > > > @@ -464,6 +464,55 @@ 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)) > > > > > > > > > > > + > > > > > > > > > > > +void 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; > > > > > > > > > > > + > > > > > > > > > > > + 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); > > > > > > > > > > > +} > > > > > > > > > > > + > > > > > > > > > > > +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..96c13b1398f8 100644 > > > > > > > > > > > --- a/drivers/virtio/virtio_pci_common.h > > > > > > > > > > > +++ b/drivers/virtio/virtio_pci_common.h > > > > > > > > > > > @@ -115,6 +115,10 @@ 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_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..fbf87239c920 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 +179,72 @@ 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, > > > > > > > > > > > + vq_reset_callback_t *callback, void *data) > > > > > > > > > > > +{ > > > > > > > > > > > + struct virtio_pci_device *vp_dev = to_vp_device(vdev); > > > > > > > > > > > + struct virtio_pci_modern_device *mdev = &vp_dev->mdev; > > > > > > > > > > > + struct virtio_pci_vq_info *info; > > > > > > > > > > > + u16 msix_vec; > > > > > > > > > > > + void *buf; > > > > > > > > > > > + > > > > > > > > > > > + 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); > > > > > > > > > > > + > > > > > > > > > > > + 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)); > > > > > > > > > > > + > > > > > > > > > > > + while ((buf = virtqueue_detach_unused_buf(info->vq)) != NULL) > > > > > > > > > > > + callback(vdev, buf, data); > > > > > > > > > > > + > > > > > > > > > > > + vp_del_reset_vq(vdev, queue_index); > > > > > > > > > > > + > > > > > > > > > > > + return 0; > > > > > > > > > > > +} > > > > > > > > > > > + > > > > > > > > > > > +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 +464,8 @@ 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 = { > > > > > > > > > > > @@ -413,6 +484,8 @@ 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 */ > > > > > > > > > > > -- > > > > > > > > > > > 2.31.0 > > > > > > > > > > > > > > > > > > > > > > > > > > >