qemu experts, please help.
This is seen with the latest qemu 1.5 (commit
62c339c5272ce8fbe8ca52695cee8ff40da7872e), guest VM stalls intermittently.
Setup:2) start a linux guest with a PTY device, for example
<serial type='pty'>
<source path='/dev/pts/4'/>
<target port='0'/>
<alias name='serial0'/>
</serial>
<console type='pty' tty='/dev/pts/4'>
<source path='/dev/pts/4'/>
<target type='serial' port='0'/>
<alias name='serial0'/>
</console>
3) Bind pty device to a slow tty device
socat -d /dev/pts/4 /dev/ttyS0,raw,b9600,echo=0
4) on serial console, writes lots of message, for example
repeat 10000 echo "`date`: this is a long long long long long long long test
message"
5) on the host, 'strace -f -p' kvm device, noticed that trace stalls once a
while. In addition, if you login via ssh to the guest, note that the login
shell stalls intermittently.
