> This could be some missing or buggy emulation. Maybe if you can get some > debug logs from kernel that could tell what it's doing. Usually at least -d > unimp,guest_errors options are recommended for debugging but if nothing is > printed then it's harder to find out what's causing the hang.
This was kernel dying in ata subsystem: [ 1.340000] io scheduler noop registered [ 1.340000] io scheduler deadline registered [ 1.340000] io scheduler cfq registered (default) [ 1.352000] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled [ 1.388000] console [ttyS0] disabled [ 1.424000] serial8250.0: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A [ 1.432000] console [ttyS0] enabled [ 1.432000] console [ttyS0] enabled [ 1.432000] bootconsole [early0] disabled [ 1.432000] bootconsole [early0] disabled [ 1.472000] scsi0 : pata_via [ 1.476000] scsi1 : pata_via [ 1.480000] ata1: PATA max UDMA/100 cmd 0x4450 ctl 0x4460 bmdma 0x4440 [ 1.484000] ata2: PATA max UDMA/100 cmd 0x4458 ctl 0x4464 bmdma 0x4448 [ 1.524000] serio: i8042 KBD port at 0x60,0x64 irq 1 [ 1.524000] serio: i8042 AUX port at 0x60,0x64 irq 12 [ 1.532000] mousedev: PS/2 mouse device common for all mice [ 1.552000] rtc_cmos rtc_cmos: rtc core: registered rtc_cmos as rtc0 [ 1.552000] rtc_cmos rtc_cmos: alarms up to one day, 114 bytes nvram [ 1.556000] ledtrig-cpu: registered to indicate activity on CPUs [ 1.556000] TCP: cubic registered [ 1.560000] NET: Registered protocol family 10 [ 1.588000] mip6: Mobile IPv6 [ 1.588000] NET: Registered protocol family 17 [ 1.588000] mpls_gso: MPLS GSO support [ 1.596000] registered taskstats version 1 [ 1.612000] rtc_cmos rtc_cmos: setting system clock to 2019-03-06 15:48:12 UTC (1551887292) [ 1.684000] input: AT Raw Set 2 keyboard as /devices/platform/i8042/serio0/input/input0 [ 1.724000] ata1.00: ATA-7: QEMU HARDDISK, 2.5+, max UDMA/100 [ 1.724000] ata1.00: 204800 sectors, multi 16: LBA48 [ 1.728000] ata1.00: limited to UDMA/33 due to 40-wire cable [ 1.736000] ata1.00: configured for UDMA/33 [ 1.796000] scsi 0:0:0:0: Direct-Access ATA QEMU HARDDISK 2.5+ PQ: 0 ANSI: 5 [ 1.820000] sd 0:0:0:0: [sda] 204800 512-byte logical blocks: (104 MB/100 MiB) [ 1.832000] sd 0:0:0:0: [sda] Write Protect is off [ 1.836000] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 1.864000] Data bus error, epc == ffffffff804157d8, ra == ffffffff804f7ddc [ 1.864000] Oops[#1]: for mips64el-softmmu/qemu-system-mips64el -M fulong2e -kernel /dev/shm/boot/vmlinux-3.16.0-4-loongson-2e -hda /dev/shm/LONGSOON_disk -cdrom /dev/shm/debian-8.0.0-mipsel-xfce-CD-1.iso -nographic -d unimp,guest_errors -append "console=ttyS0" > VMLINUX_3.16.log 2>&1 and without ata disk but with just CD it moved into 'normal' panic (no root device) [ 1.480000] console [ttyS0] enabled [ 1.480000] console [ttyS0] enabled [ 1.484000] bootconsole [early0] disabled [ 1.484000] bootconsole [early0] disabled [ 1.524000] scsi0 : pata_via [ 1.528000] scsi1 : pata_via [ 1.532000] ata1: PATA max UDMA/100 cmd 0x4450 ctl 0x4460 bmdma 0x4440 [ 1.536000] ata2: PATA max UDMA/100 cmd 0x4458 ctl 0x4464 bmdma 0x4448 [ 1.580000] serio: i8042 KBD port at 0x60,0x64 irq 1 [ 1.584000] serio: i8042 AUX port at 0x60,0x64 irq 12 [ 1.596000] mousedev: PS/2 mouse device common for all mice [ 1.616000] rtc_cmos rtc_cmos: rtc core: registered rtc_cmos as rtc0 [ 1.616000] rtc_cmos rtc_cmos: alarms up to one day, 114 bytes nvram [ 1.620000] ledtrig-cpu: registered to indicate activity on CPUs [ 1.624000] TCP: cubic registered [ 1.624000] NET: Registered protocol family 10 [ 1.648000] mip6: Mobile IPv6 [ 1.652000] NET: Registered protocol family 17 [ 1.652000] mpls_gso: MPLS GSO support [ 1.656000] registered taskstats version 1 [ 1.688000] rtc_cmos rtc_cmos: setting system clock to 2019-03-06 15:50:38 UTC (1551887438) [ 1.752000] input: AT Raw Set 2 keyboard as /devices/platform/i8042/serio0/input/input0 [ 1.912000] ata2.00: ATAPI: QEMU DVD-ROM, 2.5+, max UDMA/100 [ 1.916000] ata2.00: limited to UDMA/33 due to 40-wire cable [ 1.924000] ata2.00: configured for UDMA/33 [ 2.604000] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input2 [ 6.928000] ata2.00: qc timeout (cmd 0xa0) [ 6.928000] ata2.00: TEST_UNIT_READY failed (err_mask=0x4) [ 7.088000] ata2.00: configured for UDMA/33 [ 12.092000] ata2.00: qc timeout (cmd 0xa0) [ 12.096000] ata2.00: TEST_UNIT_READY failed (err_mask=0x4) [ 12.096000] ata2.00: limiting speed to UDMA/33:PIO3 [ 12.252000] ata2.00: configured for UDMA/33 [ 17.252000] ata2.00: qc timeout (cmd 0xa0) [ 17.252000] ata2.00: TEST_UNIT_READY failed (err_mask=0x4) [ 17.256000] ata2.00: disabled [ 17.260000] ata2: soft resetting link [ 17.420000] ata2: EH complete [ 17.428000] VFS: Cannot open root device "(null)" or unknown-block(0,0): error -6 [ 17.428000] Please append a correct "root=" boot option; here are the available partitions: [ 17.432000] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) [ 17.432000] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) vmlinux-2e also boots (if I redirect output to serial console), but not very verbose :/ Scaning.... ========================================================= ========================================================= not find usb drivers... mips64el-softmmu/qemu-system-mips64el -M fulong2e -kernel /dev/shm/vmlinux-2e -cdrom /dev/shm/debian-8.0.0-mipsel-xfce-CD-1.iso -nographic -d unimp,guest_errors -append "console=ttyS0" Hm. Note I skipped adding ati-vga device in those tests, because Debian 3.16 kernel was panicing in radeon code too.
