Hi, i wanted to test Blu-ray burning and attached a BD recorder via USB to the host. Its power was switched on, before i booted the host.
The host can operate this drive. But the qemu guest obviously has severe problems with it. There is a 'QEMU DVD-ROM' at /dev/sr0. There is also a /dev/sr1, which does not show up in the udev file /etc/udev/rules.d/70-persistent-cd.rules which usually reacts on new drives. Neither the superuser (nor the normal user after chmod a+rw) can operate /dev/sr1. xorriso gets INQUIRY 12 00 00 00 24 00 +++ sense data = F0 00 0B 00 00 00 00 0A 00 00 00 00 00 06 00 00 00 00 +++ key=B asc=00h ascq=06h ( 30992 ms) and my qemu printf reports posix-aio-compat.c: handle_aiocb_ioctl: ioctl(12, 0x2285, ), ret= -1 , errno= 19 That's ENODEV /* No such device */. Note well, that for having a failing iotcl() i first had to open the device file successfully. So "No such device" is probably related to an unprovoked re-attaching of the drive which i found in the host system log. (See below.) ---------------------------------------------------------------------- When i shutdown the guest system, the host got a kernel Oops. All my SSH sessions on the host are frozen. Except a session which ran top, they all display: Message from syslogd@debian2 at Nov 6 08:47:42 ... kernel:[ 1961.576375] Oops: 0000 [#1] SMP Message from syslogd@debian2 at Nov 6 08:47:42 ... kernel:[ 1961.576382] last sysfs file: /sys/devices/pci0000:00/0000:00:12.0/usb3/3-3/3-3:1.0/host9/target9:0:0/9:0:0:0/block/sr2/removable Message from syslogd@debian2 at Nov 6 08:47:42 ... kernel:[ 1961.576598] Stack: Message from syslogd@debian2 at Nov 6 08:47:42 ... kernel:[ 1961.576630] Call Trace: Message from syslogd@debian2 at Nov 6 08:47:42 ... kernel:[ 1961.576748] Code: 48 8b 47 18 48 8b 00 48 8b 40 60 48 85 c0 74 06 49 89 c3 41 ff e3 48 c7 86 a0 00 00 00 00 00 00 00 31 c0 c3 48 8b 47 18 48 8b 00 <48> 8b 40 68 48 85 c0 74 09 48 89 f7 49 89 c3 41 ff e3 c3 48 8b Message from syslogd@debian2 at Nov 6 08:47:42 ... kernel:[ 1961.576824] CR2: 0000000000000068 Funnily the graphical login screen of the host did still react on the keyboard but froze after i entered the desktop user password. I had to press the hardware reset button. ------------------------------------------------------------------------ The qemu start command is the same as with the previous successful runs. Only the /dev/sg address differs. I double checked before starting qemu, it is the right /dev/sg for the drive. .../x86_64-softmmu/qemu-system-x86_64 \ -L .../qemu-git/pc-bios \ -enable-kvm \ -nographic \ -m 512 \ -net nic,model=ne2k_pci \ -net user,hostfwd=tcp::5557-:22 \ -hda /dvdbuffer/i386-install.qemu \ -drive file=/dev/sg3,if=scsi \ -cdrom /dvdbuffer/pseudo_drive qemu was started by a normal user, not by the superuser. ------------------------------------------------------------------------ The drive is an 'Optiarc' 'BD RW BD-5300S' revision '1.04' attached via SATA to an USB box "Delock 5.25 inch enclosure eSATA/USB". Nov 6 08:15:06 debian2 kernel: [ 1.294442] usb 1-3: Product: JM20336 SATA, USB Combo Nov 6 08:15:06 debian2 kernel: [ 1.294444] usb 1-3: Manufacturer: JMicron Nov 6 08:15:06 debian2 kernel: [ 1.294445] usb 1-3: SerialNumber: 306663601043 The drive attachment messages first talk of "8:0:0:0" Nov 6 08:15:06 debian2 kernel: [ 6.301719] scsi 8:0:0:0: CD-ROM Optiarc BD RW BD-5300S 1.04 PQ: 0 ANSI: 0 Nov 6 08:15:06 debian2 kernel: [ 6.310686] sr2: scsi3-mmc drive: 48x/48x writer dvd-ram cd/rw xa/form2 cdda tray Nov 6 08:15:06 debian2 kernel: [ 6.310868] sr 8:0:0:0: Attached scsi generic sg3 type 5 and later of "9:0:0:0" after a disconnect which i cannot relate to a physical event on bus or power supply: Nov 6 08:35:31 debian2 kernel: [ 1232.103847] usb 1-3: USB disconnect, address 3 Nov 6 08:35:31 debian2 kernel: [ 1232.111661] sg_rq_end_io: device detached Nov 6 08:35:32 debian2 kernel: [ 1233.480103] usb 1-3: new high speed USB device using ehci_hcd and address 5 Nov 6 08:35:33 debian2 kernel: [ 1233.976106] usb 3-3: new full speed USB device using ohci_hcd and address 3 Nov 6 08:35:33 debian2 kernel: [ 1234.135535] usb 3-3: not running at top speed; connect to a high speed hub Nov 6 08:35:33 debian2 kernel: [ 1234.147516] usb 3-3: New USB device found, idVendor=152d, idProduct=2336 Nov 6 08:35:33 debian2 kernel: [ 1234.147525] usb 3-3: New USB device strings: Mfr=1, Product=2, SerialNumber=5 Nov 6 08:35:33 debian2 kernel: [ 1234.147531] usb 3-3: Product: JM20336 SATA, USB Combo Nov 6 08:35:33 debian2 kernel: [ 1234.147536] usb 3-3: Manufacturer: JMicron Nov 6 08:35:33 debian2 kernel: [ 1234.147540] usb 3-3: SerialNumber: 306663601043 Nov 6 08:35:33 debian2 kernel: [ 1234.147752] usb 3-3: configuration #1 chosen from 1 choice Nov 6 08:35:33 debian2 kernel: [ 1234.153804] scsi9 : SCSI emulation for USB Mass Storage devices Nov 6 08:35:38 debian2 kernel: [ 1239.163858] scsi 9:0:0:0: CD-ROM Optiarc BD RW BD-5300S 1.04 PQ: 0 ANSI: 0 Nov 6 08:35:38 debian2 kernel: [ 1239.173821] sr2: scsi3-mmc drive: 125x/125x writer dvd-ram cd/rw xa/form2 cdda tray Nov 6 08:35:38 debian2 kernel: [ 1239.174216] sr 9:0:0:0: Attached scsi generic sg4 type 5 This might have been the moment when i first accessed the drive from within the guest. The timestamp is a bit late for the qemu start. It is too early for the Oops and my graphical login attempt. It would match somehow above "No such device" message of qemu posix-aio-compat.c: handle_aiocb_ioctl: ioctl(12, 0x2285, ), ret= -1 , errno= 19 In any case the host switched the drive from sg3 to sg4, while qemu was told to use it as sg3. The next lines in the log are those from Oops event: Nov 6 08:47:42 debian2 kernel: [ 1961.576365] PGD 11894c067 PUD 118964067 PMD 0 Nov 6 08:47:42 debian2 kernel: [ 1961.576391] CPU 0 Nov 6 08:47:42 debian2 kernel: [ 1961.576395] Modules linked in: sco powernow_k8 ppdev lp cpufreq_powersave bridge cpufreq_stats stp bnep cpufreq_conservative rfcomm cpufreq_userspace l2cap crc16 bluetooth rfkill kvm_amd kvm binfmt_misc fuse loop snd_hda_codec_atihdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq snd_timer snd_seq_device snd radeon ttm drm_kms_helper soundcore drm i2c_algo_bit i2c_piix4 shpchp snd_page_alloc i2c_core k10temp pci_hotplug edac_core edac_mce_amd evdev parport_pc parport button pcspkr processor ext3 jbd mbcache usbhid hid sg sr_mod sd_mod crc_t10dif cdrom ata_generic usb_storage ahci ohci_hcd thermal pata_atiixp libata ehci_hcd r8169 mii scsi_mod usbcore nls_base thermal_sys [last unloaded: scsi_wait_scan] Nov 6 08:47:42 debian2 kernel: [ 1961.576508] Pid: 15, comm: events/0 Not tainted 2.6.32-5-amd64 #1 GA-MA74GM-S2H Nov 6 08:47:42 debian2 kernel: [ 1961.576515] RIP: 0010:[<ffffffff81176533>] [<ffffffff81176533>] elv_put_request+0x7/0x1a Nov 6 08:47:42 debian2 kernel: [ 1961.576528] RSP: 0018:ffff880127ac5db8 EFLAGS: 00010006 Nov 6 08:47:42 debian2 kernel: [ 1961.576533] RAX: 0000000000000000 RBX: ffff8801100cfce0 RCX: 000000000000087d Nov 6 08:47:42 debian2 kernel: [ 1961.576539] RDX: ffff880124f62b80 RSI: ffff8801100cfce0 RDI: ffff880123fc11a0 Nov 6 08:47:42 debian2 kernel: [ 1961.576545] RBP: 0000000001082c40 R08: ffff880127ac4000 R09: ffff880005215780 Nov 6 08:47:42 debian2 kernel: [ 1961.576551] R10: ffff88012775a0c0 R11: ffff88012609cde8 R12: ffff880123fc11a0 Nov 6 08:47:42 debian2 kernel: [ 1961.576556] R13: 0000000000000282 R14: ffff880127ac8000 R15: ffff880127ac8000 Nov 6 08:47:42 debian2 kernel: [ 1961.576564] FS: 00007fb63e148700(0000) GS:ffff880005200000(0000) knlGS:0000000000000000 Nov 6 08:47:42 debian2 kernel: [ 1961.576570] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b Nov 6 08:47:42 debian2 kernel: [ 1961.576575] CR2: 0000000000000068 CR3: 00000001189f4000 CR4: 00000000000006f0 Nov 6 08:47:42 debian2 kernel: [ 1961.576581] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Nov 6 08:47:42 debian2 kernel: [ 1961.576587] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Nov 6 08:47:42 debian2 kernel: [ 1961.576594] Process events/0 (pid: 15, threadinfo ffff880127ac4000, task ffff880127ac8000) Nov 6 08:47:42 debian2 kernel: [ 1961.576602] ffffffff8117e967 ffff880123fc11a0 0000000000000000 ffff8801100cfce0 Nov 6 08:47:42 debian2 kernel: [ 1961.576610] <0> ffffffff8117ef14 ffff88012600e078 ffff88012600e000 ffff88012600f290 Nov 6 08:47:42 debian2 kernel: [ 1961.576620] <0> ffffffffa00f775e ffff88012600f288 ffff88012600e000 ffff880123da86c0 Nov 6 08:47:42 debian2 kernel: [ 1961.576640] [<ffffffff8117e967>] ? __blk_put_request+0x7b/0xb0 Nov 6 08:47:42 debian2 kernel: [ 1961.576649] [<ffffffff8117ef14>] ? blk_put_request+0x26/0x3a Nov 6 08:47:42 debian2 kernel: [ 1961.576663] [<ffffffffa00f775e>] ? sg_finish_rem_req+0x5e/0xda [sg] Nov 6 08:47:42 debian2 kernel: [ 1961.576675] [<ffffffffa00f7821>] ? sg_remove_sfp_usercontext+0x1c/0xbb [sg] Nov 6 08:47:42 debian2 kernel: [ 1961.576675] [<ffffffffa00f7821>] ? sg_remove_sfp_usercontext+0x1c/0xbb [sg] Nov 6 08:47:42 debian2 kernel: [ 1961.576686] [<ffffffff810618e7>] ? worker_thread+0x188/0x21d Nov 6 08:47:42 debian2 kernel: [ 1961.576697] [<ffffffffa00f7805>] ? sg_remove_sfp_usercontext+0x0/0xbb [sg] Nov 6 08:47:42 debian2 kernel: [ 1961.576706] [<ffffffff81064f1a>] ? autoremove_wake_function+0x0/0x2e Nov 6 08:47:42 debian2 kernel: [ 1961.576715] [<ffffffff8106175f>] ? worker_thread+0x0/0x21d Nov 6 08:47:42 debian2 kernel: [ 1961.576721] [<ffffffff81064c4d>] ? kthread+0x79/0x81 Nov 6 08:47:42 debian2 kernel: [ 1961.576731] [<ffffffff81011baa>] ? child_rip+0xa/0x20 Nov 6 08:47:42 debian2 kernel: [ 1961.576738] [<ffffffff81064bd4>] ? kthread+0x0/0x81 Nov 6 08:47:42 debian2 kernel: [ 1961.576744] [<ffffffff81011ba0>] ? child_rip+0x0/0x20 Nov 6 08:47:42 debian2 kernel: [ 1961.576821] RSP <ffff880127ac5db8> Nov 6 08:47:42 debian2 kernel: [ 1961.576830] ---[ end trace c4a3be0d337e533d ]--- Then come lines from the reboot: Nov 6 08:56:19 debian2 kernel: imklog 4.6.4, log source = /proc/kmsg started. ------------------------------------------------------------------------------ I will now try to attach the drive via eSATA. Have a nice day :) Thomas