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

[Tomasz Chmielewski <mangoo@wpkg.org>]

Luca Tettamanti wrote:
> On Mon, Oct 19, 2009 at 2:14 PM, Tomasz Chmielewski <mangoo@wpkg.org> 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)?


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

Generally, I see that 0x80 is reserved for "other/unspecified" types of 
devices from a given PCI class.


Let me know if I'm asking a stupid question ;)



C 01  Mass storage controller
         00  SCSI storage controller
         01  IDE interface
         02  Floppy disk controller
         03  IPI bus controller
         04  RAID bus controller
         05  ATA controller
                 20  ADMA single stepping
                 30  ADMA continuous operation
         06  SATA controller
                 00  Vendor specific
                 01  AHCI 1.0
         07  Serial Attached SCSI controller
         80  Mass storage controller


-- 
Tomasz Chmielewski
http://wpkg.org