Re: lspci says: "SCSI storage controller: Qumranet, Inc. Virtio block device". Is it really?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Oct 19, 2009 at 3:31 PM, Tomasz Chmielewski <mangoo@xxxxxxxx> wrote:
> Luca Tettamanti wrote:
>>
>> On Mon, Oct 19, 2009 at 2:14 PM, Tomasz Chmielewski <mangoo@xxxxxxxx>
>> wrote:
>>>
>>> lspci implies that the virtio block device is a "SCSI storage
>>> controller",
>>> i.e.:
>>>
>>> 00:05.0 SCSI storage controller: Qumranet, Inc. Virtio block device
>>>
>>>
>>> However, virtio block devide does not have much to do with SCSI (in
>>> sense:
>>> sdparm does not think it is a SCSI device; virtio_blk does not depend on
>>> any
>>> SCSI moduled like sd_mod).
>>>
>>> Is "SCSI storage controller" a proper description for this device?
>>
>> It does not talk SCSI protocol if that's what you're asking. The
>> description you see comes from the PCI class (storage controller) and
>> subclass (SCSI controller); the meaning of the class/subclass is fixed
>> by the PCI standard.
>
> So why was "SCSI storage controller" any better than "IDE interface" or
> "SATA controller" for virtio block device, if it does not talk SCSI protocol
> (other than "SCSI storage controller" being the first on the list of
> subclasses)?

Because both ATA and SATA classes have a generic driver that would try
to bind to that controller (and the whole point of virtio block device
is to avoid emulating a ATA/SATA controller).

> Doesn't "80  Mass storage controller" ("0x80    0x00    Other mass storage
> controller") fit better for virtio block device?

Maybe. I guess that are compatibility problem with "other" operating systems.

Luca
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [DMA Engine]     [Linux Coverity]     [Linux USB]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Greybus]

  Powered by Linux