Re: qemu-4.0.1: vhost_region_add_section:Section rounded to 0 prior to previous a0000

From: Peter Lieven <pl@kamp.de>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: qemu-4.0.1: vhost_region_add_section:Section rounded to 0 prior to previous a0000
Date: Mon, 20 Jan 2020 10:32:56 +0100	[thread overview]
Message-ID: <70f7fc38-61f8-e018-5730-d4d0cb3db639@kamp.de> (raw)
In-Reply-To: <20200117155909.GM3209@work-vm>

Am 17.01.20 um 16:59 schrieb Dr. David Alan Gilbert:
> * Peter Lieven (pl@kamp.de) wrote:
>> Am 16.01.20 um 21:26 schrieb Dr. David Alan Gilbert:
>>> * Peter Lieven (pl@kamp.de) wrote:
>>>> Am 16.01.20 um 13:47 schrieb Peter Lieven:
>>>>> Am 13.01.20 um 17:25 schrieb Peter Lieven:
>>>>>> Am 09.01.20 um 19:44 schrieb Dr. David Alan Gilbert:
>>>>>>> * Peter Lieven (pl@kamp.de) wrote:
>>>>>>>> Am 08.01.20 um 16:04 schrieb Dr. David Alan Gilbert:
>>>>>>>>> * Peter Lieven (pl@kamp.de) wrote:
>>>>>>>>>> Hi,
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> I have a Qemu 4.0.1 machine with vhost-net network adapter, thats polluting the log with the above message.
>>>>>>>>>>
>>>>>>>>>> Is this something known? Googling revealed the following patch in Nemu (with seems to be a Qemu fork from Intel):
>>>>>>>>>>
>>>>>>>>>> https://github.com/intel/nemu/commit/03940ded7f5370ce7492c619dccced114ef7f56e
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> The network stopped functioning. After a live-migration the vServer is reachable again.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Any ideas?
>>>>>>>>> What guest are you running and what does your qemu commandline look
>>>>>>>>> like?
>>>>>>>> Its running debian9. We have hundreds of other VMs with identical setup. Do not know why this one makes trouble.
>>>>>>> Could you extract an 'info mtree' from it - particularly the
>>>>>>> 'address-space: memory' near the top.
>>>>>> Here we go:
>>>>>>
>>>>>>
>>>>>> address-space: memory
>>>>>>    0000000000000000-ffffffffffffffff (prio 0, i/o): system
>>>>>>      0000000000000000-000000003fffffff (prio 0, i/o): alias ram-below-4g @pc.ram 0000000000000000-000000003fffffff
>>>>>>      0000000000000000-ffffffffffffffff (prio -1, i/o): pci
>>>>>>        00000000000a0000-00000000000affff (prio 2, i/o): alias vga.chain4 @vga.vram 0000000000000000-000000000000ffff
>>>>>>        00000000000a0000-00000000000bffff (prio 1, i/o): vga-lowmem
>>>>> What seems special is that the RAM area is prio2. Any idea if this makes trouble?
>>>> Update from my side. This happens when I have Debian 10 with XFCE when the Graphical User Interface is initialized.
>>>>
>>>> I see the log message when I specify -M pc-i440fx-2.9. If I obmit the machine type the error does not appear.
>>> I can't persuade this to reproduce here on the images I currently have;
>>> but if you can rebuild, can you try the v3 of 'Fix hyperv synic on
>>> vhost' I've just posted?  It turns off the alignment code that's
>>> spitting that error in vhost-kernel cases, so should go away.
>> Your patch also seems to fix also my issue. No more errors and the network keeps responding.
> Great, can you reply to that post with a Tested-by ?

I was not sure if I should reply since the patch is for a total different issue.

Anyway, please feel free to add a

Tested-by: Peter Lieven <pl@kamp.de>

I am currently not subscribed to qemu-devel so I can't reply directly.

Best,

Peter