This regression is specific to the "socket" chardev and was caused by
this commit:
commit 271094474b65de1ad7aaf729938de3d9b9d0d36f (refs/bisect/bad)
Author: Dima Stepanov <dimas...@yandex-team.ru>
Date: Thu May 28 12:11:18 2020 +0300
char-socket: return -1 in case of disconnect during tcp_chr_write
During testing of the vhost-user-blk reconnect functionality the qemu
SIGSEGV was triggered:
start qemu as:
x86_64-softmmu/qemu-system-x86_64 -m 1024M -M q35 \
-object
memory-backend-file,id=ram-node0,size=1024M,mem-path=/dev/shm/qemu,share=on \
-numa node,cpus=0,memdev=ram-node0 \
-chardev socket,id=chardev0,path=./vhost.sock,noserver,reconnect=1 \
-device vhost-user-blk-pci,chardev=chardev0,num-queues=4 --enable-kvm
start vhost-user-blk daemon:
./vhost-user-blk -s ./vhost.sock -b test-img.raw
If vhost-user-blk will be killed during the vhost initialization
process, for instance after getting VHOST_SET_VRING_CALL command, then
QEMU will fail with the following backtrace:
Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x00005555559272bb in vhost_user_read (dev=0x7fffef2d53e0,
msg=0x7fffffffd5b0)
at ./hw/virtio/vhost-user.c:260
260 CharBackend *chr = u->user->chr;
#0 0x00005555559272bb in vhost_user_read (dev=0x7fffef2d53e0,
msg=0x7fffffffd5b0)
at ./hw/virtio/vhost-user.c:260
#1 0x000055555592acb8 in vhost_user_get_config (dev=0x7fffef2d53e0,
config=0x7fffef2d5394 "", config_len=60)
at ./hw/virtio/vhost-user.c:1645
#2 0x0000555555925525 in vhost_dev_get_config (hdev=0x7fffef2d53e0,
config=0x7fffef2d5394 "", config_len=60)
at ./hw/virtio/vhost.c:1490
#3 0x00005555558cc46b in vhost_user_blk_device_realize
(dev=0x7fffef2d51a0, errp=0x7fffffffd8f0)
at ./hw/block/vhost-user-blk.c:429
#4 0x0000555555920090 in virtio_device_realize (dev=0x7fffef2d51a0,
errp=0x7fffffffd948)
at ./hw/virtio/virtio.c:3615
#5 0x0000555555a9779c in device_set_realized (obj=0x7fffef2d51a0,
value=true, errp=0x7fffffffdb88)
at ./hw/core/qdev.c:891
...
The problem is that vhost_user_write doesn't get an error after
disconnect and try to call vhost_user_read(). The tcp_chr_write()
routine should return -1 in case of disconnect. Indicate the EIO error
if this routine is called in the disconnected state.
Signed-off-by: Dima Stepanov <dimas...@yandex-team.ru>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
Message-Id:
<aeb7806bfc945faadf09f64dcfa30f59de3ac053.1590396396.git.dimas...@yandex-team.ru>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1893691
Title:
Chardev logfile is not written (regression between 5.0 and 5.1)
Status in QEMU:
New
Bug description:
After update from version 5.0 to 5.1, logfile stopped being populated
with console output. The file is being created, but remains empty.
Relevant command line options:
-mon chardev=char0
-serial chardev:char0
-chardev
socket,host=127.0.0.10,port=2323,server,nowait,telnet,mux=on,id=char0,logfile=/home/jurkiew/.machiner/runs/2020-08-31T21:46:55-0/internal/log
Full command line:
qemu-system-x86_64
-nodefaults
-no-user-config
-snapshot
-enable-kvm
-cpu
host
-nographic
-echr
17
-mon
chardev=char0
-serial
chardev:char0
-rtc
clock=vm
-object
rng-random,filename=/dev/urandom,id=rng0
-device
virtio-rng-pci,rng=rng0,max-bytes=512,period=1000
-name
2020-08-31T21:46:55-0,debug-threads=on
-smp
sockets=1,cores=9,threads=2
-m
251G
-overcommit
cpu-pm=on
-pidfile
/home/jurkiew/.machiner/runs/2020-08-31T21:46:55-0/internal/pid
-net
nic,model=virtio
-net
user,hostfwd=tcp:127.0.0.10:2222-:22,hostfwd=tcp:127.0.0.10:8000-:8000,hostfwd=tcp:127.0.0.10:9000-:9000
-fsdev
local,id=machiner_internal_dir,security_model=none,path=/home/jurkiew/.machiner/runs/2020-08-31T21:46:55-0/internal
-device
virtio-9p-pci,fsdev=machiner_internal_dir,mount_tag=machiner_internal_dir
-fsdev
local,id=machiner_lower_dir,security_model=none,readonly,path=.
-device
virtio-9p-pci,fsdev=machiner_lower_dir,mount_tag=machiner_lower_dir
-fsdev
local,id=machiner_upper_dir,security_model=mapped-xattr,fmode=0777,dmode=0777,path=/home/jurkiew/.machiner/runs/2020-08-31T21:46:55-0
-device
virtio-9p-pci,fsdev=machiner_upper_dir,mount_tag=machiner_upper_dir
-device
virtio-scsi
-drive
if=none,file=/home/jurkiew/.machiner/images/famtar/image.qcow2,discard=on,id=famtar
-device
scsi-hd,drive=famtar
-chardev
socket,host=127.0.0.10,port=2323,server,nowait,telnet,mux=on,id=char0,logfile=/home/jurkiew/.machiner/runs/2020-08-31T21:46:55-0/internal/log
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