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

[Wenchao Xia]

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 The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is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.

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?
  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)

ENV:
 nested KVM:

                       RH6.4
(Qemu Virtual CPU 1.5.50, Linux 3.10.0.rc3)
                          |  (100M vhost-scsi hooked with file backend)
                       RH6.4
(Common KVM processer, Linux 3.10.0.rc3,
qemu-system-x86_64 1.5.50+, 6a4e17711442849bf2cc731ccddef5a2a2d92d29,
seabios 1.7.2.2, e9725dd76d5d7212cb4a97fd18ff2599538955cf)
                          |
                      Fefora 18
(Intel Xeon X5650, Linux version 3.8.11-200.fc18.x86_64,
 QEMU emulator version 1.2.2)

Invocation details:
  On RH6.4 host:
  1  with root, execute following script to prepare configfs system:

FILEIO=fileio_1
IMAGE=/home/xiawenc/Work/qemu/test/test1.raw
SIZE=104857600
QEMU_WWPN=naa.600140554cf3a1fe
NEXUS=naa.60014053226f03f8

mkdir -p /sys/kernel/config/target/core/$FILEIO/fileio
echo "fd_dev_name=$IMAGE,fd_dev_size=$SIZE" > 
/sys/kernel/config/target/core/$FILEIO/fileio/control
echo 1 > /sys/kernel/config/target/core/$FILEIO/fileio/enable

mkdir -p /sys/kernel/config/target/vhost/$QEMU_WWPN/tpgt_0/lun/lun_0
ln -sf /sys/kernel/config/target/core/$FILEIO/fileio/ 
/sys/kernel/config/target/vhost/$QEMU_WWPN/tpgt_0/lun/lun_0/virtual_scsi_port
echo $NEXUS > /sys/kernel/config/target/vhost/$QEMU_WWPN/tpgt_0/nexus

  2 invoke qemu, test_guest_RH64.qcow2 is a pre-made disk containing
RH6.4 system:

x86_64-softmmu/qemu-system-x86_64     --enablem 1024 -drive 
file=/mnt/nfs/test_guest_RH64.qcow2,if=ide,cache=writethrough -vnc 
0.0.0.0:10 -L mybios/ -device 
vhost-scsi-pci,wwpn=naa.600140554cf3a1fe,event_idx=off


--
Best Regards

Wenchao Xia