kvm process exit on virtio error

kvm process exit on virtio error

[Phil Ten]

Hello, 

My kvm processes are exiting on what I think are VIRTIO errors:

Guest moved used index from 24543 to 24606

1) Network specific settings:

I am required to hide the Mac address of the kvm guest, therefore I added 
the following line in /etc/network/interface on the host:

up route add -net GUEST_IP netmask 255.255.255.255 dev vmbr0

this routes the traffic via the host IP and therefore hides the guest IP address.

2) I replaced virtio by rtl8139 and had no problem so far.

 

Background:

I am running a proxmox 1.1 host hosted by OVH. I have kvm guests running 
windows 2003 server SP2 with VIRTIO network. and unfortunately, 
these guest are crashing after a few hours at the most.

virtio installed: NETKVM-20081229.iso

To gather more information, I launched kvm via a command line.
When the kvm process exit it output the error message :

Guest moved used index from 24543 to 24606

kvm cmd line:

/usr/bin/kvm -monitor unix:/var/run/qemu-server/103.mon,server,nowait -vnc unix:/var/run/qemu-server/103.vnc,password -pidfile /var/run/qemu-server/103.pid -usbdevice tablet -name Seeclic_Web -smp 1 -id 103 -cpuunits 1000 -vga cirrus -tdf -localtime -k fr -drive file=/var/lib/vz/images/103/vm-103-disk-1.qcow2,if=ide,index=1 -drive file=/var/lib/vz/images/103/vm-103-disk.qcow2,if=ide,index=0,boot=on -drive file=/var/lib/vz/template/iso/NETKVM-20081229.iso,if=ide,index=2,media=cdrom -m 2048 -net tap,vlan=0,ifname=vmtab103i0,script=/var/lib/qemu-server/bridge-vlan0 -net nic,vlan=0,model=virtio,macaddr=26:57:C0:D4:E1:55

root@ns205568:~# uname -a
Linux ns205568.ovh.net 2.6.24-2-pve #1 SMP PREEMPT Wed Jan 14 11:32:49 CET 2009 x86_64 GNU/Linux

root@ns205568:~# pveversion -v
pve-manager: 1.1-3 (pve-manager/1.1/3718)
qemu-server: 1.0-7
pve-kernel: 2.6.24-5
pve-kvm: 83-1
pve-firmware: not correctly installed
vncterm: 0.9-1
vzctl: 3.0.23-1pve1
vzdump: 1.1-1
vzprocps: 2.0.11-1dso2
vzquota: 3.0.11-1dso1

Phil Ten

Re: kvm process exit on virtio error

[Mark McLoughlin]

Hi,

On Wed, 2009-02-11 at 12:41 +0100, Phil Ten wrote:
> Hello, 
> 
> My kvm processes are exiting on what I think are VIRTIO errors:
> 
> Guest moved used index from 24543 to 24606

This is very strange. The code in question is:

static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx)
{
    uint16_t num_heads = vring_avail_idx(vq) - idx;

	/* Check it isn't doing very strange things with descriptor numbers. */
    if (num_heads > vq->vring.num) {
        fprintf(stderr, "Guest moved used index from %u to %u",
	            idx, vring_avail_idx(vq));
        exit(1);
...

i.e. for virtio_net, vq->vring.num == 256 and 24606 - 24543 == 63, so it
doesn't make much sense.

Does this happen under heavy network traffic? Have you tried virtio_blk?

Thanks,
Mark.

Re: kvm process exit on virtio error

[Phil Ten]

Hello Mark, 

I am not sure about what you mean by heavy network traffic.

Here are more details:

This is a test server. I installed the host and created two VMs 
with Windows 2003 Server. I am the only one to use this configuration.
On both VMs, I added a openssh server (from cygwin). Then, I started 
uploading files by SFTP using filezilla client.  After a few thousands files 
uploaded succesfully I get the error I reported. I tried many times 
and got the same symptom each time.

My filezilla send two files concurrently at approximatively 2.5 Mbytes/s each.

And that is all. No other application installed, no other network connections.

I add that I am fairly new to kvm. I havn't tried virtio_blk.

So far, I confirm, no problem with rtl8139.

Best Regards,
Phil Ten

----- Original Message -----
From: "Mark McLoughlin" <markmc@redhat.com>
To: "Phil Ten" <phil.info@dafweb.com>
Cc: kvm@vger.kernel.org
Sent: Wednesday, February 11, 2009 8:59:46 PM GMT +01:00 Amsterdam / Berlin / Bern / Rome / Stockholm / Vienna
Subject: Re: kvm process exit on virtio error

Hi,

On Wed, 2009-02-11 at 12:41 +0100, Phil Ten wrote:
> Hello, 
> 
> My kvm processes are exiting on what I think are VIRTIO errors:
> 
> Guest moved used index from 24543 to 24606

This is very strange. The code in question is:

static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx)
{
    uint16_t num_heads = vring_avail_idx(vq) - idx;

	/* Check it isn't doing very strange things with descriptor numbers. */
    if (num_heads > vq->vring.num) {
        fprintf(stderr, "Guest moved used index from %u to %u",
	            idx, vring_avail_idx(vq));
        exit(1);
...

i.e. for virtio_net, vq->vring.num == 256 and 24606 - 24543 == 63, so it
doesn't make much sense.

Does this happen under heavy network traffic? Have you tried virtio_blk?

Thanks,
Mark.