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

[Asias He <asias@redhat.com>]

On Wed, May 29, 2013 at 08:10:44AM -0700, Badari Pulavarty wrote:
> 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The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is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).

Hmm, interesting. Will look into it.

Nick, Any ideas here?

> Thanks,
> Badari
> 

-- 
Asias