Re: [Qemu-devel] hostdev / iSCSI issue in QEMU 2.7

[Kevin Wolf]

Am 01.09.2016 um 22:21 hat Holger Schranz geschrieben:
> Hello,
> 
> we need help for an issue we have sice QEMU 2.7.
> May be we use the wrong mailing list. If so please let me know which
> mail list we have to use to report problems in QEMU.
> 
> Best regards
> 
> Holger

Eric, a quick look suggests that this might be related to your recent
changes to the iscsi driver. Can you have a look?

Maybe what we really need to do is avoid calling bdrv_refresh_limits()
for devices with bs->sg == true.

Kevin

> ===================================================================================
> 
> We use the following libvirt-descrption for a tape-device and a
> changer-device:
> 
>     <hostdev mode='subsystem' type='scsi' managed='no' rawio='yes'>
>       <source protocol='iscsi'
> name='iqn.2008-09.net.fsc:server.LT260_61005/1'>
>       <host name='192.168.200.53' port='3260'/>
>       </source>
>       <address type='drive' controller='2' bus='0' target='2' unit='2'/>
>     </hostdev>
> 
> <!-- Media changer -->
>     <hostdev mode='subsystem' type='scsi' managed='no' rawio='yes'>
>       <source protocol='iscsi'
> name='iqn.2008-09.net.fsc:server.LT260_61005/3'>
>       <host name='192.168.200.53' port='3260'/>
>       </source>
>       <address type='drive' controller='2' bus='0' target='2' unit='6'/>
>     </hostdev>
> 
> We use tgt as iSCSI-Server.
> 
> With qemu 2.6 it works fine.
> 
> With qemu 2.7RC4 we got the following error:
> 
> Thread 1 "qemu-system-x86" received signal SIGFPE, Arithmetic exception.
> 0x0000555555c207e2 in iscsi_refresh_limits (bs=0x5555568236f0,
>     errp=0x7fffffffcca8) at
> /home/kvm/SOURCES/qemu-2.7.0-rc4/block/iscsi.c:1838
> 1838        if (iscsilun->bl.max_ws_len < 0xffffffff /
> iscsilun->block_size) {
> 
> The function iscsi_refresh_limits is changed in 2.7RC4 and devides by
> iscsilun->block_size,
> but the block size is filled only for SCSI-type TYPE_DISK and TYPE_ROM in
> /home/kvm/SOURCES/qemu-2.7.0-rc4/block/iscsi.c:1378 (function
> iscsi_readcapacity_sync)
> 
> If the libvirt-construction (see above) is correct, there is no chance
> in qemu 2.7
> to use a tape-device or changer via iscsi.
> 
> !!! If we should change the definition, please let us know. !!!
> 
> Backtrace:
>  Thread 1 "qemu-system-x86" received signal SIGFPE, Arithmetic exception.
> 0x0000555555c207e2 in iscsi_refresh_limits (bs=0x5555568236f0,
>     errp=0x7fffffffcca8) at
> /home/kvm/SOURCES/qemu-2.7.0-rc4/block/iscsi.c:1838
> 1838        if (iscsilun->bl.max_ws_len < 0xffffffff /
> iscsilun->block_size) {
> (gdb) bt
> #0  0x0000555555c207e2 in iscsi_refresh_limits (bs=0x5555568236f0,
> errp=0x7fffffffcca8) at /home/kvm/SOURCES/qemu-2.7.0-rc4/block/iscsi.c:1838
> #1  0x0000555555c018d4 in bdrv_refresh_limits (bs=0x5555568236f0,
> errp=0x7fffffffcca8) at /home/kvm/SOURCES/qemu-2.7.0-rc4/block/io.c:121
> #2  0x0000555555b9627a in bdrv_open_common (bs=0x5555568236f0, file=0x0,
> options=0x555556827950, errp=0x7fffffffcd58)
>     at /home/kvm/SOURCES/qemu-2.7.0-rc4/block.c:1013
> #3  0x0000555555b97e3b in bdrv_open_inherit (filename=0x5555567de840
> "iscsi://192.168.200.53:3260/iqn.2008-09.net.fsc%3Aserver.LT260_61005/1",
> reference=0x0, options=0x555556827950, flags=57346,
> parent=0x55555681d450, child_role=
>     0x555556165360 <child_file>, errp=0x7fffffffcea8)
>     at /home/kvm/SOURCES/qemu-2.7.0-rc4/block.c:1687
> #4  0x0000555555b97524 in bdrv_open_child (filename=0x5555567de840
> "iscsi://192.168.200.53:3260/iqn.2008-09.net.fsc%3Aserver.LT260_61005/1",
> options=0x5555568216b0, bdref_key=0x555555d78112 "file",
> parent=0x55555681d450, child_role=
>     0x555556165360 <child_file>, allow_none=true, errp=0x7fffffffcea8)
>     at /home/kvm/SOURCES/qemu-2.7.0-rc4/block.c:1449
> #5  0x0000555555b97cb9 in bdrv_open_inherit (filename=0x5555567de840
> "iscsi://192.168.200.53:3260/iqn.2008-09.net.fsc%3Aserver.LT260_61005/1",
> reference=0x0, options=0x5555568216b0, flags=8194, parent=0x0, child_role=
>     0x0, errp=0x7fffffffd1d8) at
> /home/kvm/SOURCES/qemu-2.7.0-rc4/block.c:1648
> #6  0x0000555555b9825c in bdrv_open (filename=0x5555567de840
> "iscsi://192.168.200.53:3260/iqn.2008-09.net.fsc%3Aserver.LT260_61005/1",
> reference=0x0, options=0x5555567ed240, flags=2, errp=0x7fffffffd1d8)
>     at /home/kvm/SOURCES/qemu-2.7.0-rc4/block.c:1778
> #7  0x0000555555beef4f in blk_new_open (filename=0x5555567de840
> "iscsi://192.168.200.53:3260/iqn.2008-09.net.fsc%3Aserver.LT260_61005/1",
> reference=0x0, options=0x5555567ed240, flags=2, errp=0x7fffffffd1d8)
>     at /home/kvm/SOURCES/qemu-2.7.0-rc4/block/block-backend.c:160
> #8  0x00005555558ce2bb in blockdev_init (file=0x5555567de840
> "iscsi://192.168.200.53:3260/iqn.2008-09.net.fsc%3Aserver.LT260_61005/1",
> bs_opts=0x5555567ed240, errp=0x7fffffffd1d8) at
> /home/kvm/SOURCES/qemu-2.7.0-rc4/blockdev.c:597
> #9  0x00005555558cf576 in drive_new (all_opts=0x555556766fd0,
> block_default_type=IF_IDE) at
> /home/kvm/SOURCES/qemu-2.7.0-rc4/blockdev.c:1132
> #10 0x00005555558eaec9 in drive_init_func (opaque=0x5555567787b0,
> opts=0x555556766fd0, errp=0x0) at /home/kvm/SOURCES/qemu-2.7.0-rc4/vl.c:1138
> #11 0x0000555555c9ab9d in qemu_opts_foreach (list=0x555556184fe0
> <qemu_drive_opts>, func=0x5555558eae8a <drive_init_func>,
> opaque=0x5555567787b0, errp=0x0)
>     at /home/kvm/SOURCES/qemu-2.7.0-rc4/util/qemu-option.c:1116
> #12 0x00005555558f434a in main (argc=85, argv=0x7fffffffd6e8,
> envp=0x7fffffffd998) at /home/kvm/SOURCES/qemu-2.7.0-rc4/vl.c:4401
> 
> ---
> Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft.
> https://www.avast.com/antivirus
> 
>