| 2013-09-12 12:04:15 |
Richard Jones |
bug |
|
|
added bug |
| 2013-09-12 12:05:59 |
Richard Jones |
description |
virtio-serial appears to lose writes, but only when used on top of virtio-mmio. The scenario is this:
/home/rjones/d/qemu/arm-softmmu/qemu-system-arm \
-global virtio-blk-device.scsi=off \
-nodefconfig \
-nodefaults \
-nographic \
-M vexpress-a15 \
-machine accel=kvm:tcg \
-m 500 \
-no-reboot \
-kernel /home/rjones/d/libguestfs/tmp/.guestfs-1001/kernel.27944 \
-dtb /home/rjones/d/libguestfs/tmp/.guestfs-1001/dtb.27944 \
-initrd /home/rjones/d/libguestfs/tmp/.guestfs-1001/initrd.27944 \
-device virtio-scsi-device,id=scsi \
-drive file=/home/rjones/d/libguestfs/tmp/libguestfsLa9dE2/scratch.1,cache=unsafe,format=raw,id=hd0,if=none \
-device scsi-hd,drive=hd0 \
-drive file=/home/rjones/d/libguestfs/tmp/.guestfs-1001/root.27944,snapshot=on,id=appliance,cache=unsafe,if=none \
-device scsi-hd,drive=appliance \
-device virtio-serial-device \
-serial stdio \
-chardev socket,path=/home/rjones/d/libguestfs/tmp/libguestfsLa9dE2/guestfsd.sock,id=channel0 \
-device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
-append 'panic=1 mem=500M console=ttyAMA0 udevtimeout=600 no_timer_check acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1 TERM=xterm-256color'
After the guest starts up, a daemon writes 4 bytes to a virtio-serial socket. The host side reads these 4 bytes correctly and writes a 64 byte message. The guest never sees this message.
I enabled virtio-mmio debugging, and this is what is printed (## = my comment):
## guest opens the socket:
trying to open virtio-serial channel '/dev/virtio-ports/org.libguestfs.channel.0'
virtio_mmio: virtio_mmio_write offset 0x50 value 0x3
opened the socket, sock = 3
udevadm settle
## guest writes 4 bytes to the socket:
virtio_mmio: virtio_mmio_write offset 0x50 value 0x5
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
sent magic GUESTFS_LAUNCH_FLAG
## host reads 4 bytes successfully:
main_loop libguestfs: recv_from_daemon: received GUESTFS_LAUNCH_FLAG
libguestfs: [14605ms] appliance is up
Guest launched OK.
## host writes 64 bytes to socket:
libguestfs: writing the data to the socket (size = 64)
waiting for next request
libguestfs: data written OK
## hangs here forever with guest in read() call never receiving any data
I am using qemu from git today (2d1fe1873a984). |
virtio-serial appears to lose writes, but only when used on top of virtio-mmio. The scenario is this:
/home/rjones/d/qemu/arm-softmmu/qemu-system-arm \
-global virtio-blk-device.scsi=off \
-nodefconfig \
-nodefaults \
-nographic \
-M vexpress-a15 \
-machine accel=kvm:tcg \
-m 500 \
-no-reboot \
-kernel /home/rjones/d/libguestfs/tmp/.guestfs-1001/kernel.27944 \
-dtb /home/rjones/d/libguestfs/tmp/.guestfs-1001/dtb.27944 \
-initrd /home/rjones/d/libguestfs/tmp/.guestfs-1001/initrd.27944 \
-device virtio-scsi-device,id=scsi \
-drive file=/home/rjones/d/libguestfs/tmp/libguestfsLa9dE2/scratch.1,cache=unsafe,format=raw,id=hd0,if=none \
-device scsi-hd,drive=hd0 \
-drive file=/home/rjones/d/libguestfs/tmp/.guestfs-1001/root.27944,snapshot=on,id=appliance,cache=unsafe,if=none \
-device scsi-hd,drive=appliance \
-device virtio-serial-device \
-serial stdio \
-chardev socket,path=/home/rjones/d/libguestfs/tmp/libguestfsLa9dE2/guestfsd.sock,id=channel0 \
-device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
-append 'panic=1 mem=500M console=ttyAMA0 udevtimeout=600 no_timer_check acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1 TERM=xterm-256color'
After the guest starts up, a daemon writes 4 bytes to a virtio-serial socket. The host side reads these 4 bytes correctly and writes a 64 byte message. The guest never sees this message.
I enabled virtio-mmio debugging, and this is what is printed (## = my comment):
## guest opens the socket:
trying to open virtio-serial channel '/dev/virtio-ports/org.libguestfs.channel.0'
virtio_mmio: virtio_mmio_write offset 0x50 value 0x3
opened the socket, sock = 3
udevadm settle
## guest writes 4 bytes to the socket:
virtio_mmio: virtio_mmio_write offset 0x50 value 0x5
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
sent magic GUESTFS_LAUNCH_FLAG
## host reads 4 bytes successfully:
main_loop libguestfs: recv_from_daemon: received GUESTFS_LAUNCH_FLAG
libguestfs: [14605ms] appliance is up
Guest launched OK.
## host writes 64 bytes to socket:
libguestfs: writing the data to the socket (size = 64)
waiting for next request
libguestfs: data written OK
## hangs here forever with guest in read() call never receiving any data
I am using qemu from git today (2d1fe1873a984).
Some notes:
- It's not 100% reproducible. Sometimes everything works fine, although it fails "often" (eg > 2/3rds of the time).
- KVM is being used.
- We've long used virtio-serial on x86 and have never seen anything like this. |
|
| 2013-09-12 12:55:33 |
Richard Jones |
description |
virtio-serial appears to lose writes, but only when used on top of virtio-mmio. The scenario is this:
/home/rjones/d/qemu/arm-softmmu/qemu-system-arm \
-global virtio-blk-device.scsi=off \
-nodefconfig \
-nodefaults \
-nographic \
-M vexpress-a15 \
-machine accel=kvm:tcg \
-m 500 \
-no-reboot \
-kernel /home/rjones/d/libguestfs/tmp/.guestfs-1001/kernel.27944 \
-dtb /home/rjones/d/libguestfs/tmp/.guestfs-1001/dtb.27944 \
-initrd /home/rjones/d/libguestfs/tmp/.guestfs-1001/initrd.27944 \
-device virtio-scsi-device,id=scsi \
-drive file=/home/rjones/d/libguestfs/tmp/libguestfsLa9dE2/scratch.1,cache=unsafe,format=raw,id=hd0,if=none \
-device scsi-hd,drive=hd0 \
-drive file=/home/rjones/d/libguestfs/tmp/.guestfs-1001/root.27944,snapshot=on,id=appliance,cache=unsafe,if=none \
-device scsi-hd,drive=appliance \
-device virtio-serial-device \
-serial stdio \
-chardev socket,path=/home/rjones/d/libguestfs/tmp/libguestfsLa9dE2/guestfsd.sock,id=channel0 \
-device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
-append 'panic=1 mem=500M console=ttyAMA0 udevtimeout=600 no_timer_check acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1 TERM=xterm-256color'
After the guest starts up, a daemon writes 4 bytes to a virtio-serial socket. The host side reads these 4 bytes correctly and writes a 64 byte message. The guest never sees this message.
I enabled virtio-mmio debugging, and this is what is printed (## = my comment):
## guest opens the socket:
trying to open virtio-serial channel '/dev/virtio-ports/org.libguestfs.channel.0'
virtio_mmio: virtio_mmio_write offset 0x50 value 0x3
opened the socket, sock = 3
udevadm settle
## guest writes 4 bytes to the socket:
virtio_mmio: virtio_mmio_write offset 0x50 value 0x5
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
sent magic GUESTFS_LAUNCH_FLAG
## host reads 4 bytes successfully:
main_loop libguestfs: recv_from_daemon: received GUESTFS_LAUNCH_FLAG
libguestfs: [14605ms] appliance is up
Guest launched OK.
## host writes 64 bytes to socket:
libguestfs: writing the data to the socket (size = 64)
waiting for next request
libguestfs: data written OK
## hangs here forever with guest in read() call never receiving any data
I am using qemu from git today (2d1fe1873a984).
Some notes:
- It's not 100% reproducible. Sometimes everything works fine, although it fails "often" (eg > 2/3rds of the time).
- KVM is being used.
- We've long used virtio-serial on x86 and have never seen anything like this. |
virtio-serial appears to lose writes, but only when used on top of virtio-mmio. The scenario is this:
/home/rjones/d/qemu/arm-softmmu/qemu-system-arm \
-global virtio-blk-device.scsi=off \
-nodefconfig \
-nodefaults \
-nographic \
-M vexpress-a15 \
-machine accel=kvm:tcg \
-m 500 \
-no-reboot \
-kernel /home/rjones/d/libguestfs/tmp/.guestfs-1001/kernel.27944 \
-dtb /home/rjones/d/libguestfs/tmp/.guestfs-1001/dtb.27944 \
-initrd /home/rjones/d/libguestfs/tmp/.guestfs-1001/initrd.27944 \
-device virtio-scsi-device,id=scsi \
-drive file=/home/rjones/d/libguestfs/tmp/libguestfsLa9dE2/scratch.1,cache=unsafe,format=raw,id=hd0,if=none \
-device scsi-hd,drive=hd0 \
-drive file=/home/rjones/d/libguestfs/tmp/.guestfs-1001/root.27944,snapshot=on,id=appliance,cache=unsafe,if=none \
-device scsi-hd,drive=appliance \
-device virtio-serial-device \
-serial stdio \
-chardev socket,path=/home/rjones/d/libguestfs/tmp/libguestfsLa9dE2/guestfsd.sock,id=channel0 \
-device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
-append 'panic=1 mem=500M console=ttyAMA0 udevtimeout=600 no_timer_check acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1 TERM=xterm-256color'
After the guest starts up, a daemon writes 4 bytes to a virtio-serial socket. The host side reads these 4 bytes correctly and writes a 64 byte message. The guest never sees this message.
I enabled virtio-mmio debugging, and this is what is printed (## = my comment):
## guest opens the socket:
trying to open virtio-serial channel '/dev/virtio-ports/org.libguestfs.channel.0'
virtio_mmio: virtio_mmio_write offset 0x50 value 0x3
opened the socket, sock = 3
udevadm settle
## guest writes 4 bytes to the socket:
virtio_mmio: virtio_mmio_write offset 0x50 value 0x5
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
sent magic GUESTFS_LAUNCH_FLAG
## host reads 4 bytes successfully:
main_loop libguestfs: recv_from_daemon: received GUESTFS_LAUNCH_FLAG
libguestfs: [14605ms] appliance is up
Guest launched OK.
## host writes 64 bytes to socket:
libguestfs: writing the data to the socket (size = 64)
waiting for next request
libguestfs: data written OK
## hangs here forever with guest in read() call never receiving any data
I am using qemu from git today (2d1fe1873a984).
Some notes:
- It's not 100% reproducible. Sometimes everything works fine, although it fails "often" (eg > 2/3rds of the time).
- KVM is being used.
- We've long used virtio-serial on x86 and have never seen anything like this.
This is what the output looks like when it doesn't fail:
trying to open virtio-serial channel '/dev/virtio-ports/org.libguestfs.channel.0
'
virtio_mmio: virtio_mmio_write offset 0x50 value 0x3
opened the socket, sock = 3
udevadm settle
virtio_mmio: virtio_mmio_write offset 0x50 value 0x5
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
sent magic GUESTlibguestfs: recv_from_daemon: received GUESTFS_LAUNCH_FLAG
libguestfs: [14710ms] appliance is up
Guest launched OK.
libguestfs: writing the data to the socket (size = 64)
FS_LAUNCH_FLAG
main_loop waiting for next request
libguestfs: data written OK
virtio_mmio: virtio_mmio_write offset 0x50 value 0x2
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_write offset 0x50 value 0x2
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x0
virtio_mmio: virtio_mmio setting IRQ 0
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
[... more virtio-mmio lines omitted ...]
virtio_mmio: virtio_mmio_write offset 0x64 value 0x0
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
guestfsd: main_loop: new request, len 0x3c
virtio_mmio: virtio_mmio_write offset 0x50 value 0x4
0000: 20 00 f5 f5 00 00 00 04 00 00 00 d2 00 00 00 00 | ...............|virtio_mmio: virtio_mmio_write offset 0x50 value 0x2
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
0010: 00 12 34 00 00 00 00 00 00 00 00 00 00 00 00 00 |..4.............|
0020: 00 00 00 00 00 00 00 00 00 00 00 08 2f 64 65 76 |............/dev|
0030: 2f 73 64 61 00 00 00 03 6d 62 72 00 |/sda....mbr. |
virtio_mmio: virtio_mmio_write offset 0x50 value 0x2
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0
virtio_mmio: virtio_mmio_write offset 0x50 value 0x2
virtio_mmio: virtio_mmio setting IRQ 1
virtio_mmio: virtio_mmio_read offset 0x60
virtio_mmio: virtio_mmio_write offset 0x64 value 0x1
virtio_mmio: virtio_mmio setting IRQ 0 |
|
| 2013-09-12 14:33:29 |
Richard Jones |
attachment added |
|
strace -f -o /tmp/strace.txt qemu-system-arm [...] https://bugs.launchpad.net/qemu/+bug/1224444/+attachment/3817795/+files/strace.txt |
|
| 2013-09-12 14:38:15 |
Richard Jones |
attachment added |
|
working strace -f https://bugs.launchpad.net/qemu/+bug/1224444/+attachment/3817814/+files/strace-working.txt |
|
| 2017-03-04 14:08:32 |
Richard Jones |
qemu: status |
New |
Fix Released |
|
