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Re: [Qemu-devel] virtio-blk-pci: how to tell if it is CD or HDD?
From: |
Alexander Graf |
Subject: |
Re: [Qemu-devel] virtio-blk-pci: how to tell if it is CD or HDD? |
Date: |
Thu, 17 Oct 2013 15:02:50 +0200 |
On 17.10.2013, at 14:54, Paolo Bonzini <address@hidden> wrote:
> Il 17/10/2013 14:38, Alexey Kardashevskiy ha scritto:
>> qdev_get_fw_dev_path:
>> /spapr-vio-bridge/spapr-vscsi/address@hidden/address@hidden,2 suffix=(null)
>> /spapr-vio-bridge/spapr-vscsi/address@hidden/address@hidden,1 suffix=(null)
>
> You need to implement qdev_fw_get_path to change
>
> spapr-vio-bridge -> vdevice
> spapr-vscsi -> address@hidden
>
>> /address@hidden/address@hidden suffix=/address@hidden
>
> The extra suffix is not a problem since you can parse a prefix successfully.
>
>> /address@hidden/address@hidden/address@hidden/address@hidden,2 suffix=(null)
>> /address@hidden/address@hidden/address@hidden/address@hidden,1 suffix=(null)
>
> I guess this is virtio-scsi.
>
>> SLOF:
>> 0 > devalias
>> cdrom123 : /address@hidden/address@hidden/address@hidden
>> cdrom12 : /address@hidden/address@hidden/address@hidden
>> hvterm : /vdevice/address@hidden
>> net : /address@hidden/address@hidden
>> scsi : /vdevice/address@hidden
>> cdrom1 : /vdevice/address@hidden/address@hidden
>> cdrom : /vdevice/address@hidden/address@hidden
>> nvram : /vdevice/address@hidden ok
>>
>>
>> In ideal world I would want to get in QEMU what SLOF can understand and
>> pass this to SLOF. But QEMU APIs return something which cannot be converted
>> straight away.
>>
>> Or I could simply put bootindex to the device tree nodes (as
>> "qemu,bootindex") but in this case "wildcard" nodes support fails as there
>> is just a single node "/vdevice/address@hidden/disk" in the device tree
>> for all LUNs. And we definitely do not want to create nodes for all disk
>> devices.
>>
>> Or I can implement a "smart" converter from QEMU strings to OF pathnames.
>>
>> Or I can implement third set of callbacks, something like qdev_OF_dev_path().
>>
>> Or not support "bootindex" at all.
>>
>> All possibilities suck but which one sucks less? :) Thanks!
>
> In general, try to make QEMU produce SLOF APIs by modifying the devices
> that instantiate the buses.
But please make sure to not block the path for non-SLOF machines. -M mac99
should still be able to get different path names for PCI devices for example.
Alex