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

[Badari Pulavarty]

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 <address@hidden>
> > > > > > >
> > > > > > > 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 The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is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