Re: [Qemu-devel] [PATCH 6/9] vhost-scsi: new device supporting the tcm_vhost Linux kernel module

[Badari Pulavarty <pbadari@us.ibm.com>]

On 05/29/2013 02:05 AM, Wenchao Xia wrote:
> 于 2013-5-28 17:00, Wenchao Xia 写道:
>> 于 2013-5-28 16:33, Asias He 写道:
>>> On Tue, May 28, 2013 at 10:01:14AM +0200, Paolo Bonzini wrote:
>>>> Il 28/05/2013 09:13, Wenchao Xia ha scritto:
>>>>>>> From: Nicholas Bellinger <nab@linux-iscsi.org>
>>>>>>>
>>>>>>> The WWPN specified in configfs is passed to "-device 
>>>>>>> vhost-scsi-pci".
>>>>>>> The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is
>>>>>>> not
>>>>>>> available from the QEMU command-line.  Instead, I hardcode it to
>>>>>>> zero.
>>>>>>>
>>>>> Hi, Paolo
>>>>>    Any document about how to config it correctly in configfs, before
>>>>> invoking qemu with the WWPN number?
>>>>
>>>> Unfortunately no, but vhost-scsi doesn't have many knobs (unlike
>>>> iSCSI for example) so it's quite simple.  Here is an example:
>>>>
>>>> cd /sys/kernel/config/target
>>>> mkdir -p core/fileio_0/fileio
>>>> echo 'fd_dev_name=/home/pbonzini/test.img,fd_dev_size=5905580032' >
>>>> core/fileio_0/fileio/control
>>>> echo 1 > core/fileio_0/fileio/enable
>>>> mkdir -p vhost/naa.600140554cf3a18e/tpgt_0/lun/lun_0
>>>> cd vhost/naa.600140554cf3a18e/tpgt_0
>>>> ln -sf ../../../../../core/fileio_0/fileio/ 
>>>> lun/lun_0/virtual_scsi_port
>>>> echo naa.60014053226f0388 > nexus
>>>>
>>>> The "nexus" value is the initiator WWN. naa.600140554cf3a18e is the
>>>> target WWN that you have to pass to "-device vhost-scsi-pci".
>>>>
>>>> Paolo
>>>
>>> For me, I always use targetcli utils instead of the sysfs interface.
>>> targetcli in F18 has vhost support now.
>>>
>>    Thanks very much for above information, I'll try it for test.
>>
>   I have done a basic test of vhost-scsi, following is the result I'd
> like to post, generally it seems fine:
>
> Result:
>   fdisk/mkfs: fdisk can find it, mke2fs works fine.
>   mount: can mount it.
>   file I/O: dd 90M zero to a file in that disk succeed.



I tried without nested kvm.

>
> Issues:
>   1) in fdisk -l, sometime timeout with dmesg "end_request: I/O error,
> dev  fd0, sector 0", I guess it is caused by nested KVM that failed
> to kick host kernel?


I don't see this issue. Are you sure "fd0" is actually the scsi device ?
what is "fd0" ?

>   2) in fdisk -l, it shows 512 bytes larger than the parameter I
> specified in fd_dev_size parameter in configfs on host.(shows
> 104858112 bytes, see the invocation script below)
>

I see the same. For some reason "fdisk -l" in the VM shows
512-bytes more than the actual size for the file (on the host).

Thanks,
Badari