Verification successful with the kernel in xenial-proposed. Updating verification tags.
Details ======= Guest: --- root@mfo-sf194614:~# apt-cache madison linux-image-4.4.0-139-generic linux-image-4.4.0-139-generic | 4.4.0-139.165 | http://archive.ubuntu.com/ubuntu/ xenial-proposed/main amd64 Packages root@mfo-sf194614:~# apt-get -y install linux-image-4.4.0-139-generic root@mfo-sf194614:~# reboot root@mfo-sf194614:~# uname -a Linux mfo-sf194614 4.4.0-139-generic #165-Ubuntu SMP Wed Oct 24 10:58:50 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux root@mfo-sf194614:~# ls -ld /sys/block/sda lrwxrwxrwx 1 root root 0 Oct 25 13:51 /sys/block/sda -> ../devices/pci0000:00/0000:00:07.0/virtio4/host2/target2:0:0/2:0:0:0/block/sda root@mfo-sf194614:~# lspci -s 7.0 00:07.0 SCSI storage controller: Red Hat, Inc Virtio SCSI root@mfo-sf194614:~# echo 9 > /proc/sys/kernel/printk root@mfo-sf194614:~# scsi_logging_level --set --mlqueue=4 --mlcomplete=2 root@mfo-sf194614:~# dd if=/dev/sda of=/dev/null count=1 [ 139.412030] sd 2:0:0:0: [sda] tag#1 Send: scmd 0xffff880036e614f0 [ 139.415541] sd 2:0:0:0: [sda] tag#1 CDB: Read(10) 28 00 00 00 00 00 00 00 20 00 [ 139.418561] sd 2:0:0:0: [sda] tag#1 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK [ 139.421753] sd 2:0:0:0: [sda] tag#1 CDB: Read(10) 28 00 00 00 00 00 00 00 20 00 [ 139.424561] sd 2:0:0:0: tag#1 Send: scmd 0xffff880036e614f0 [ 139.427081] sd 2:0:0:0: tag#1 CDB: Test Unit Ready 00 00 00 00 00 00 [ 139.428997] sd 2:0:0:0: tag#1 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK [ 139.430982] sd 2:0:0:0: tag#1 CDB: Test Unit Ready 00 00 00 00 00 00 root@mfo-sf194614:~# cat /sys/module/virtio_scsi/sections/.text 0xffffffffc0002000 Host: --- mfo@rotom:~/ddebs$ vscsi_text='0xffffffffc0002000' mfo@rotom:~/ddebs$ virsh qemu-monitor-command mfo-sf194614 --hmp 'gdbserver' mfo@rotom:~/ddebs$ wget http://ddebs.ubuntu.com/pool/main/l/linux/linux-image-4.4.0-139-generic-dbgsym_4.4.0-139.165_amd64.ddeb mfo@rotom:~/ddebs$ dpkg-deb -x linux-image-4.4.0-139-generic-dbgsym_4.4.0-139.165_amd64.ddeb linux-image-4.4.0-139-generic-dbgsym_4.4.0-139.165_amd64/ mfo@rotom:~/ddebs$ cd linux-image-4.4.0-139-generic-dbgsym_4.4.0-139.165_amd64/usr/lib/debug/ gdb boot/vmlinux-4.4.0-139-generic \ -ex 'set confirm off' \ -ex "add-symbol-file lib/modules/4.4.0-139-generic/kernel/drivers/scsi/virtio_scsi.ko $vscsi_text" \ -ex 'break virtscsi_queuecommand' \ -ex 'target remote localhost:1234' \ -ex 'continue' Guest --- root@mfo-sf194614:~# dd if=/dev/sda of=/dev/null count=1 2>/dev/null [ 435.462432] sd 2:0:0:0: [sda] tag#1 Send: scmd 0xffff880036e614f0 [ 435.465679] sd 2:0:0:0: [sda] tag#1 CDB: Read(10) 28 00 00 00 00 00 00 00 20 00 <freeze> Host GDB: --- Thread 2 hit Breakpoint 1, virtscsi_queuecommand (vscsi=0xffff88013a6cf7d8, req_vq=0xffff88013a6cf9e8, sc=0xffff880036e614f0) at /build/linux-PrHwV2/linux-4.4.0/drivers/scsi/virtio_scsi.c:534 534 /build/linux-PrHwV2/linux-4.4.0/drivers/scsi/virtio_scsi.c: No such file or directory. (gdb) break virtio_ring.c:196 Breakpoint 2 at 0xffffffff814e383f: virtio_ring.c:196. (3 locations) (gdb) info break Num Type Disp Enb Address What 1 breakpoint keep y 0xffffffffc0003330 in virtscsi_queuecommand at /build/linux-PrHwV2/linux-4.4.0/drivers/scsi/virtio_scsi.c:534 breakpoint already hit 1 time 2 breakpoint keep y <MULTIPLE> 2.1 y 0xffffffff814e383f in virtqueue_add_sgs at /build/linux-PrHwV2/linux-4.4.0/drivers/virtio/virtio_ring.c:196 2.2 y 0xffffffff814e3dec in virtqueue_add_inbuf at /build/linux-PrHwV2/linux-4.4.0/drivers/virtio/virtio_ring.c:196 2.3 y 0xffffffff814e409c in virtqueue_add_outbuf at /build/linux-PrHwV2/linux-4.4.0/drivers/virtio/virtio_ring.c:196 (gdb) disable 1 (gdb) disable 2.2 (gdb) disable 2.3 (gdb) continue Continuing. Thread 2 hit Breakpoint 2, virtqueue_add (gfp=<optimized out>, data=<optimized out>, in_sgs=<optimized out>, out_sgs=<optimized out>, total_sg=<optimized out>, sgs=<optimized out>, _vq=<optimized out>) at /build/linux-PrHwV2/linux-4.4.0/drivers/virtio/virtio_ring.c:197 197 /build/linux-PrHwV2/linux-4.4.0/drivers/virtio/virtio_ring.c: No such file or directory. (gdb) disass Dump of assembler code for function virtqueue_add_sgs: ... => 0xffffffff814e383f <+175>: cmp %ecx,%ebx 0xffffffff814e3841 <+177>: ja 0xffffffff814e3a15 <virtqueue_add_sgs+645> ... (gdb) info reg $ecx $ebx ecx 0x80 128 ebx 0x1 1 (gdb) set $ecx = 0 (gdb) info reg $ecx $ebx ecx 0x0 0 ebx 0x1 1 (gdb) disable 2.1 (gdb) break virtscsi_target_destroy Breakpoint 3 at 0xffffffffc0002020: file /build/linux-PrHwV2/linux-4.4.0/drivers/scsi/virtio_scsi.c, line 791. (gdb) continue Continuing. Guest --- root@mfo-sf194614:~# dd if=/dev/sda of=/dev/null count=1 2>/dev/null [ 435.462432] sd 2:0:0:0: [sda] tag#1 Send: scmd 0xffff880036e614f0 [ 435.465679] sd 2:0:0:0: [sda] tag#1 CDB: Read(10) 28 00 00 00 00 00 00 00 20 00 <freeze> <continued after GDB above> [ 435.474443] sd 2:0:0:0: [sda] tag#1 queuecommand : request rejected [ 435.504597] scsi host2: unblocking host at zero depth [ 435.507603] sd 2:0:0:0: [sda] tag#1 Send: scmd 0xffff880036e614f0 [ 435.510896] sd 2:0:0:0: [sda] tag#1 CDB: Read(10) 28 00 00 00 00 00 00 00 20 00 [ 435.515713] sd 2:0:0:0: [sda] tag#1 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK [ 435.520838] sd 2:0:0:0: [sda] tag#1 CDB: Read(10) 28 00 00 00 00 00 00 00 20 00 [ 435.525044] sd 2:0:0:0: tag#1 Send: scmd 0xffff880036e614f0 [ 435.527795] sd 2:0:0:0: tag#1 CDB: Test Unit Ready 00 00 00 00 00 00 [ 435.553066] sd 2:0:0:0: tag#1 Done: SUCCESS Result: hostbyte=DID_OK driverbyte=DRIVER_OK [ 435.555822] sd 2:0:0:0: tag#1 CDB: Test Unit Ready 00 00 00 00 00 00 Host --- mfo@rotom:~$ virsh qemu-monitor-command mfo-sf194614 --hmp 'device_del scsi1-0-0-0' Guest --- [ 549.088876] sd 2:0:0:0: [sda] Synchronizing SCSI cache <...> [ 549.152828] sd 2:0:0:0: [sda] Synchronize Cache(10) failed: Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK Host GDB --- Thread 1 hit Breakpoint 3, virtscsi_target_destroy (starget=0xffff880036c62800) at /build/linux-PrHwV2/linux-4.4.0/drivers/scsi/virtio_scsi.c:791 791 /build/linux-PrHwV2/linux-4.4.0/drivers/scsi/virtio_scsi.c: No such file or directory. (gdb) disass Dump of assembler code for function virtscsi_target_destroy: => 0xffffffffc0002020 <+0>: nopl 0x0(%rax,%rax,1) 0xffffffffc0002025 <+5>: push %rbp 0xffffffffc0002026 <+6>: mov 0x328(%rdi),%rdi 0xffffffffc000202d <+13>: mov %rsp,%rbp 0xffffffffc0002030 <+16>: mov 0x4(%rdi),%eax 0xffffffffc0002033 <+19>: test %eax,%eax 0xffffffffc0002035 <+21>: je 0xffffffffc0002040 <virtscsi_target_destroy+32> 0xffffffffc0002037 <+23>: pause 0xffffffffc0002039 <+25>: mov 0x4(%rdi),%eax 0xffffffffc000203c <+28>: test %eax,%eax 0xffffffffc000203e <+30>: jne 0xffffffffc0002037 <virtscsi_target_destroy+23> 0xffffffffc0002040 <+32>: callq 0xffffffff811f64a0 <kfree> 0xffffffffc0002045 <+37>: pop %rbp 0xffffffffc0002046 <+38>: retq End of assembler dump. (gdb) si (gdb) (gdb) (gdb) (gdb) (gdb) disass Dump of assembler code for function virtscsi_target_destroy: 0xffffffffc0002020 <+0>: nopl 0x0(%rax,%rax,1) 0xffffffffc0002025 <+5>: push %rbp 0xffffffffc0002026 <+6>: mov 0x328(%rdi),%rdi 0xffffffffc000202d <+13>: mov %rsp,%rbp 0xffffffffc0002030 <+16>: mov 0x4(%rdi),%eax => 0xffffffffc0002033 <+19>: test %eax,%eax 0xffffffffc0002035 <+21>: je 0xffffffffc0002040 <virtscsi_target_destroy+32> 0xffffffffc0002037 <+23>: pause 0xffffffffc0002039 <+25>: mov 0x4(%rdi),%eax 0xffffffffc000203c <+28>: test %eax,%eax 0xffffffffc000203e <+30>: jne 0xffffffffc0002037 <virtscsi_target_destroy+23> 0xffffffffc0002040 <+32>: callq 0xffffffff811f64a0 <kfree> 0xffffffffc0002045 <+37>: pop %rbp 0xffffffffc0002046 <+38>: retq End of assembler dump. (gdb) info reg $eax eax 0x0 0 That looks good! :-) (gdb) continue Host --- And indeed, the CPU usage for the QEMU process remains low. Problem resolved. mfo@rotom:~$ pid=$(ps ax | grep qemu | grep mfo-sf194614 | cut -d' ' -f1) mfo@rotom:~$ top -b -d 1 -n 10 -p $pid | grep qemu 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.98 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.98 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.98 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.98 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.98 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.98 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.98 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.98 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 1.0 0.6 1:05.99 qemu-system-x86 10234 libvirt+ 20 0 9016056 768008 23260 S 0.0 0.6 1:05.99 qemu-system-x86 ** Tags removed: verification-needed-xenial ** Tags added: verification-done-xenial -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1798110 Title: xenial: virtio-scsi: CPU soft lockup due to loop in virtscsi_target_destroy() To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1798110/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
