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

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

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 The tgpt field of the SET_ENDPOINT ioctl is obsolete now, so it is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

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