Can you try the same with unix sockets instead of tcp sockets on the host?

(In reply to comment #2)
> Can you try the same with unix sockets instead of tcp sockets on the host?

This issue also exsits when using unix sockets.
Steps:
1. boot a guest with virtio serial device 
/usr/libexec/qemu-kvm -enable-kvm -m 2G -smp 2 -uuid ef242d8b-9faa-4785-b48b-d0a13bba094c -rtc base=utc,clock=host,driftfix=slew -boot c -drive file=/home/RHEL-Server-6.0-64-virtio.qcow2,if=none,id=drive-virtio-disk0,boot=on,format=qcow2 -device virtio-blk-pci,bus=pci.0,drive=drive-virtio-disk0,id=virtio-disk0 -netdev tap,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,mac=00:10:12:20:77:0c,bus=pci.0,addr=0x7,id=hostnet0 -usb -device usb-tablet,id=input0 -monitor stdio -vnc :1 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,vectors=4,bus=pci.0,addr=0x4 -chardev socket,id=channel0,path=/var/lib/libvirt/qemu/rhel6.channel0,server,nowait -device virtserialport,chardev=channel0,name=org.linux-kvm.port.0,bus=virtio-serial0.0,id=port0

2.In host:
nc -U /var/lib/libvirt/qemu/rhel6.channel0

3. In guest:
echo aaa > /dev/vport0p1

4. close the nc connection in host and then connect again

5. repeat step 3.

Result:
After step 3, the "aaa" display in host.
But after step 5, does not display anymore.

First, I see you're using /dev/vport0p0 in the original comment.  Don't do that; port 0 is reserved for console ports and has a special meaning.

You should also not explicitly set the 'vectors' value unless you know for sure how many ports are going to be used.  And if the vectors value is less than max_ports, MSI will be disabled for that device.

Can you try this in the guest:

while true; do echo aaaa > /dev/vport0p1; done;

after you disconnect and re-connect nc in the host?  After a while, the output should start pouring in.

If that happens, this is a dup of the Bug 621484.

BTW I can't reproduce this with unix sockets, only with tcp sockets.

(In reply to comment #4)
> First, I see you're using /dev/vport0p0 in the original comment.  Don't do
> that; port 0 is reserved for console ports and has a special meaning.
OK
> 
> You should also not explicitly set the 'vectors' value unless you know for sure
> how many ports are going to be used.  And if the vectors value is less than
> max_ports, MSI will be disabled for that device.
> 
> Can you try this in the guest:
> 
> while true; do echo aaaa > /dev/vport0p1; done;
> 
> after you disconnect and re-connect nc in the host?  After a while, the output
> should start pouring in.
> 
> If that happens, this is a dup of the Bug 621484.
Using "while true; do echo aaaa > /dev/vport0p1; done;" in the guest, I can see many "aaaa" display in host side for both tcp and unix sockets after disconnect and re-connect nc.

Repeatedly input "echo aaaa > /dev/vport0p1" or using "while true; do echo aaaa > /dev/vport0p1;sleep 1; done;"in guest after disconnect then reconnect nc in host. I find many "aaaa" lost in host side, and the output can display in host "after a while".

> 
> BTW I can't reproduce this with unix sockets, only with tcp sockets.
Still can reproduce with both unix and tpc sockets using the steps in comment 3.

I will close it as a dup of Bug 621484.


Thanks.

*** This bug has been marked as a duplicate of bug 621484 ***