Re: [RFC Patch] virtio: export model and type in /sys

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jan 31, 2011 at 10:53:00AM +0800, Amerigo Wang wrote:
> Our kdump script needs /sys/block/X/device/{vendor, model, type},

BTW, it's sys/class/block now? One is new, one is legacy and
deprecated, I am not sure which is which ...

> but virtio devices don't have {model, type}, this patch adds them.
> Actually, I don't know how to fill the model field, other block devices
> seem read it from SCSI. Any comments?
> 
> Signed-off-by: WANG Cong <amwang@redhat.com>

For model, I am guessing "virtio-blk" would be a good value.  But I
think this attribute is specific to block so should be added only for
virito-blk.
As far as I can tell, type is from scsi/scsi.h,
so we can just stick TYPE_DISK (0) there.

BTW, I note that other devices in drivers/block might not
have these either. Does your script work for xen-blkfront?
If we want this to work for all block devices maybe these
attributes should go into block core? model could
default to the driver name, type could default to 0...

> ---
> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> index efb35aa..5ce70b7 100644
> --- a/drivers/virtio/virtio.c
> +++ b/drivers/virtio/virtio.c
> @@ -17,6 +17,18 @@ static ssize_t vendor_show(struct device *_d,
>  	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
>  	return sprintf(buf, "0x%04x\n", dev->id.vendor);
>  }
> +static ssize_t model_show(struct device *_d,
> +			   struct device_attribute *attr, char *buf)
> +{
> +	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
> +	return sprintf(buf, "0x%04x\n", dev->id.model);
> +}
> +static ssize_t type_show(struct device *_d,
> +			   struct device_attribute *attr, char *buf)
> +{
> +	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
> +	return sprintf(buf, "0x%04x\n", dev->id.type);
> +}
>  static ssize_t status_show(struct device *_d,
>  			   struct device_attribute *attr, char *buf)
>  {
> @@ -49,6 +61,8 @@ static ssize_t features_show(struct device *_d,
>  static struct device_attribute virtio_dev_attrs[] = {
>  	__ATTR_RO(device),
>  	__ATTR_RO(vendor),
> +	__ATTR_RO(model),
> +	__ATTR_RO(type),
>  	__ATTR_RO(status),
>  	__ATTR_RO(modalias),
>  	__ATTR_RO(features),
> diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
> index 4fb5b2b..3bde99d 100644
> --- a/drivers/virtio/virtio_pci.c
> +++ b/drivers/virtio/virtio_pci.c
> @@ -656,6 +656,7 @@ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
>  	 * the subsystem ids */
>  	vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
>  	vp_dev->vdev.id.device = pci_dev->subsystem_device;
> +	vp_dev->vdev.id.type = pci_dev->pcie_type;
>  
>  	/* finally register the virtio device */
>  	err = register_virtio_device(&vp_dev->vdev);
> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
> index 48c007d..b72cd50 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -385,6 +385,8 @@ struct ssb_device_id {
>  struct virtio_device_id {
>  	__u32 device;
>  	__u32 vendor;
> +	__u32 model;
> +	__u32 type;
>  };
>  #define VIRTIO_DEV_ANY_ID	0xffffffff
>