2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Thomas Løcke]

Hey all,

I have 9 Windows XP guests running on a KVM host. The host is
Slackware 13.1 x86_64 with kernel 2.6.35.11.

All the guests are being accessed using the built-in RDP server in
Windows XP. This worked perfectly with qemu-kvm 0.13.0, but with
0.14.0 the connection is dropped every 5-10 minutes.

This is the command used to start the guests:

/opt/qemu-0.13.0/bin/qemu-system-x86_64 -name fdacs1sa1_15,
process=fdacs1sa1_15 \
    -pidfile /var/run/kvm/15.pid \
    -drive file=/storage_slow_one/fd_acs2_sa2.raw,snapshot=off,if=virtio,media=disk,cache=none,format=raw,boot=on
\
    -monitor unix:/var/run/kvm/15.monitor,server,nowait \
    -cpu qemu64 \
    -smp 1 \
    -m 512 \
    -k da \
    -vnc :15 \
    -rtc base=localtime,clock=host \
    -tdf \
    -net nic,macaddr=de:ad:be:ef:00:15,model=virtio \
    -net tap,ifname=tap_15,script=no,downscript=no \
    -runas kvm \
    -daemonize \
    -usbdevice tablet

The virtio drivers used are virtio-win-1.1.16.

Access via the qemu-kvm VNC interface does not experience these
connection drops. There are no visible errors in the Windows XP
guests.

Now, since I don't have any issues with qemu-kvm 0.13.0, it is not a
problem for me to go back to using this version instead of the new
0.14.0.

So:
    2.6.35.11 + 0.13.0 = Flawless operation. It just hums along.
    2.6.35.11 + 0.14.0 = The connection to the internal Windows XP RDP
server breaks every 5-10 minutes.

Anybody else who've experienced something similar?

Regards,
Thomas Løcke

Re: 2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Michael Tokarev]

08.03.2011 09:43, Thomas Løcke wrote:
> Hey all,

Hello again Thomas! :)

> I have 9 Windows XP guests running on a KVM host. The host is
> Slackware 13.1 x86_64 with kernel 2.6.35.11.
> 
> All the guests are being accessed using the built-in RDP server in
> Windows XP. This worked perfectly with qemu-kvm 0.13.0, but with
> 0.14.0 the connection is dropped every 5-10 minutes.
> 
> This is the command used to start the guests:
> 
> /opt/qemu-0.13.0/bin/qemu-system-x86_64 -name fdacs1sa1_15,
> process=fdacs1sa1_15 \
>     -pidfile /var/run/kvm/15.pid \
>     -drive file=/storage_slow_one/fd_acs2_sa2.raw,snapshot=off,if=virtio,media=disk,cache=none,format=raw,boot=on
> \

Slow ;)

>     -monitor unix:/var/run/kvm/15.monitor,server,nowait \
>     -cpu qemu64 \
>     -smp 1 \
>     -m 512 \
>     -k da \
>     -vnc :15 \
>     -rtc base=localtime,clock=host \
>     -tdf \
>     -net nic,macaddr=de:ad:be:ef:00:15,model=virtio \
>     -net tap,ifname=tap_15,script=no,downscript=no \

Try switching from the obsolete -net tap to current
-netdev syntax.  See docs/qdev-device-use.txt in the
qemu(-kvm) source tarball.  This will be quite a bit
faster too (and it works since at least 0.12).

[]
> Access via the qemu-kvm VNC interface does not experience these
> connection drops. There are no visible errors in the Windows XP
> guests.

That's interesting.  No, I for one haven't seen anything like
you describe, and it'd definitely be useful to find and fix it.
But I haven't used the old -net tap syntax for quite some time
too - i started a test winXP guest now, let's see how it will
work.

/mjt

Re: 2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Thomas Løcke]

On Tue, Mar 8, 2011 at 8:22 AM, Michael Tokarev <mjt@tls.msk.ru> wrote:
>>     -drive file=/storage_slow_one/fd_acs2_sa2.raw,snapshot=off,if=virtio,media=disk,cache=none,format=raw,boot=on
>> \
>
> Slow ;)


Yea, well. I had to name it something, and slow seemed appropriate,
given the kind of drives used in the RAID.  <g>



>>     -net nic,macaddr=de:ad:be:ef:00:15,model=virtio \
>>     -net tap,ifname=tap_15,script=no,downscript=no \
>
> Try switching from the obsolete -net tap to current
> -netdev syntax.  See docs/qdev-device-use.txt in the
> qemu(-kvm) source tarball.  This will be quite a bit
> faster too (and it works since at least 0.12).


I read that document, and I'd just like to thank you for making me
feel stupid.  :D

Honestly, I didn't understand half of what that doc were saying, so I
don't feel comfortable trying my hand at this new syntax.

Most of my qemu-kvm "knowledge" have come from this page:
http://www.linux-kvm.org/page/HOWTO

How would my current -net setup translate into the new method?

Also I see in the doc mentioned, that this new -device method is also
available as a replacement for -soundhw and -vga. Those two I do think
I understand.  hehe

Regards,
Thomas Løcke

Re: 2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Michael Tokarev]

08.03.2011 11:08, Thomas Løcke wrote:
[]
>>>     -net nic,macaddr=de:ad:be:ef:00:15,model=virtio \
>>>     -net tap,ifname=tap_15,script=no,downscript=no \
>>
>> Try switching from the obsolete -net tap to current
>> -netdev syntax.  See docs/qdev-device-use.txt in the
>> qemu(-kvm) source tarball.  This will be quite a bit
>> faster too (and it works since at least 0.12).
> 
> 
> I read that document, and I'd just like to thank you for making me
> feel stupid.  :D
> 
> Honestly, I didn't understand half of what that doc were saying, so I
> don't feel comfortable trying my hand at this new syntax.
> 
> Most of my qemu-kvm "knowledge" have come from this page:
> http://www.linux-kvm.org/page/HOWTO
> 
> How would my current -net setup translate into the new method?

 -netdev type=tap,ifname=tap_15,script=no,downscript=no,id=foo
 -device virtio-net-pci,macaddr=de:ad:be:ef:00:15,netdev=foo

(the "foo" thing is the key to join them together, can be an
arbitrary string).

> Also I see in the doc mentioned, that this new -device method is also
> available as a replacement for -soundhw and -vga. Those two I do think
> I understand.  hehe

I haven't even looked at these, -- looks scary :)

/mjt

Re: 2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Thomas Løcke]

On Tue, Mar 8, 2011 at 9:42 AM, Michael Tokarev <mjt@tls.msk.ru> wrote:
>  -netdev type=tap,ifname=tap_15,script=no,downscript=no,id=foo
>  -device virtio-net-pci,macaddr=de:ad:be:ef:00:15,netdev=foo
>
> (the "foo" thing is the key to join them together, can be an
> arbitrary string).


Obviously it had to be so simple and straightforward that it made no
sense to me.

Thank you _very_ much for this example.

:o)
Thomas Løcke

Re: 2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Michael Tokarev]

08.03.2011 09:43, Thomas Løcke wrote:
[]
>     2.6.35.11 + 0.13.0 = Flawless operation. It just hums along.
>     2.6.35.11 + 0.14.0 = The connection to the internal Windows XP RDP
> server breaks every 5-10 minutes.

I ran winXP with 4 parallel RDP connections for over a hour
here, "watching" some flash video on all 4 of them - it works
just fine here.

> Anybody else who've experienced something similar?

Not me :)

/mjt

Re: 2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Thomas Løcke]

On Tue, Mar 8, 2011 at 10:40 AM, Michael Tokarev <mjt@tls.msk.ru> wrote:
>>     2.6.35.11 + 0.13.0 = Flawless operation. It just hums along.
>>     2.6.35.11 + 0.14.0 = The connection to the internal Windows XP RDP
>> server breaks every 5-10 minutes.
>
> I ran winXP with 4 parallel RDP connections for over a hour
> here, "watching" some flash video on all 4 of them - it works
> just fine here.
>
>> Anybody else who've experienced something similar?
>
> Not me :)


Well, that sucks.

That leaves me all alone with this problem, which luckily isn't that
big deal, as everything works fine with 0.13.0.

I'll try changing the -net setup and see if that makes any difference.

Thanks for the help Michael.

:o)
Thomas Løcke

Re: 2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Avi Kivity]

On 03/08/2011 08:43 AM, Thomas Løcke wrote:
> Hey all,
>
> I have 9 Windows XP guests running on a KVM host. The host is
> Slackware 13.1 x86_64 with kernel 2.6.35.11.
>
> All the guests are being accessed using the built-in RDP server in
> Windows XP. This worked perfectly with qemu-kvm 0.13.0, but with
> 0.14.0 the connection is dropped every 5-10 minutes.
>
> This is the command used to start the guests:
>
> /opt/qemu-0.13.0/bin/qemu-system-x86_64 -name fdacs1sa1_15,
> process=fdacs1sa1_15 \
>      -pidfile /var/run/kvm/15.pid \
>      -drive file=/storage_slow_one/fd_acs2_sa2.raw,snapshot=off,if=virtio,media=disk,cache=none,format=raw,boot=on
> \
>      -monitor unix:/var/run/kvm/15.monitor,server,nowait \
>      -cpu qemu64 \
>      -smp 1 \
>      -m 512 \
>      -k da \
>      -vnc :15 \
>      -rtc base=localtime,clock=host \
>      -tdf \
>      -net nic,macaddr=de:ad:be:ef:00:15,model=virtio \
>      -net tap,ifname=tap_15,script=no,downscript=no \
>      -runas kvm \
>      -daemonize \
>      -usbdevice tablet
>
> The virtio drivers used are virtio-win-1.1.16.
>
> Access via the qemu-kvm VNC interface does not experience these
> connection drops. There are no visible errors in the Windows XP
> guests.
>
> Now, since I don't have any issues with qemu-kvm 0.13.0, it is not a
> problem for me to go back to using this version instead of the new
> 0.14.0.
>
> So:
>      2.6.35.11 + 0.13.0 = Flawless operation. It just hums along.
>      2.6.35.11 + 0.14.0 = The connection to the internal Windows XP RDP
> server breaks every 5-10 minutes.
>
> Anybody else who've experienced something similar?

You might try logging the connection with wireshark (start on the, 
perhaps later also in the guest) to see what's the cause.  If you run it 
on both guest and host, you can see if packets are lost or corrupted.

-- 
error compiling committee.c: too many arguments to function

Re: 2.6.35.11 + qemu-kvm 0.14.0 + Windows XP RDP access = unstable

[Thomas Løcke]

On Tue, Mar 8, 2011 at 11:19 AM, Avi Kivity <avi@redhat.com> wrote:
> You might try logging the connection with wireshark (start on the, perhaps
> later also in the guest) to see what's the cause.  If you run it on both
> guest and host, you can see if packets are lost or corrupted.


I tried something else first: Switched from virtio to rtl8139.

And lo and behold, it now works with 0.14.0.

So:
    kernel 2.6.35.11 + qemu-kvm 0.14.0 + virtio net 1.1.16 = Fail
    kernel 2.6.35.11 + qemu-kvm 0.14.0 + rtl8139 = Success

That solution is perfectly fine for me and my users. The guests are
not exactly hammering my network, so the rtl8139 can easily manage.

:o)
Thomas Løcke