On Fri, Jul 02, 2021 at 11:05:54PM +0800, Ming Lei wrote:
> blk-mq needs to know if the device uses managed irq, so add one field
> to virtio_device for recording if device uses managed irq.
>
> If the driver use managed irq, this flag has to be set so it can be
> passed to blk-mq.
>
> Cc: "Michael S. Tsirkin" <m...@redhat.com>
> Cc: Jason Wang <jasow...@redhat.com>
> Cc: virtualization@lists.linux-foundation.org
> Signed-off-by: Ming Lei <ming....@redhat.com>
The API seems somewhat confusing. virtio does not request
a managed irq as such, does it? I think it's a decision taken
by the irq core.
Any way to query the irq to find out if it's managed?
> ---
> drivers/block/virtio_blk.c | 2 ++
> drivers/scsi/virtio_scsi.c | 1 +
> drivers/virtio/virtio_pci_common.c | 1 +
> include/linux/virtio.h | 1 +
> 4 files changed, 5 insertions(+)
>
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index e4bd3b1fc3c2..33b9c80ac475 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -764,6 +764,8 @@ static int virtblk_probe(struct virtio_device *vdev)
> vblk->tag_set.queue_depth = queue_depth;
> vblk->tag_set.numa_node = NUMA_NO_NODE;
> vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
> + if (vdev->use_managed_irq)
> + vblk->tag_set.flags |= BLK_MQ_F_MANAGED_IRQ;
> vblk->tag_set.cmd_size =
> sizeof(struct virtblk_req) +
> sizeof(struct scatterlist) * sg_elems;
> diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
> index b9c86a7e3b97..f301917abc84 100644
> --- a/drivers/scsi/virtio_scsi.c
> +++ b/drivers/scsi/virtio_scsi.c
> @@ -891,6 +891,7 @@ static int virtscsi_probe(struct virtio_device *vdev)
> shost->max_channel = 0;
> shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
> shost->nr_hw_queues = num_queues;
> + shost->use_managed_irq = vdev->use_managed_irq;
>
> #ifdef CONFIG_BLK_DEV_INTEGRITY
> if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) {
> diff --git a/drivers/virtio/virtio_pci_common.c
> b/drivers/virtio/virtio_pci_common.c
> index 222d630c41fc..f2ac48fb477b 100644
> --- a/drivers/virtio/virtio_pci_common.c
> +++ b/drivers/virtio/virtio_pci_common.c
> @@ -128,6 +128,7 @@ static int vp_request_msix_vectors(struct virtio_device
> *vdev, int nvectors,
> if (desc) {
> flags |= PCI_IRQ_AFFINITY;
> desc->pre_vectors++; /* virtio config vector */
> + vdev->use_managed_irq = true;
> }
>
> err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> index b1894e0323fa..85cc773b2dc7 100644
> --- a/include/linux/virtio.h
> +++ b/include/linux/virtio.h
> @@ -109,6 +109,7 @@ struct virtio_device {
> bool failed;
> bool config_enabled;
> bool config_change_pending;
> + bool use_managed_irq;
> spinlock_t config_lock;
> struct device dev;
> struct virtio_device_id id;
> --
> 2.31.1
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