Re: Frame buffer corruptions with KVM >= 2.6.36

Jan Kiszka
2010-10-14T12:13:44Z

Am 14.10.2010 14:11, Avi Kivity wrote:
> On 10/14/2010 02:04 PM, Avi Kivity wrote:
>> On 10/14/2010 09:27 AM, Jan Kiszka wrote:
>>> Hi,
>>>
>>> I'm seeing quite frequent corruptions of the VESA frame buffer with
>>> Linux guests (vga=0x317) that are starting with KVM kernel modules of
>>> upcoming 2.6.36 (I'm currently running -rc7). Effects disappears when
>>> downgrading to kvm-kmod-2.6.35.6. Will see if I can bisect later, but
>>> maybe someone already has an idea or wants to reproduce (just run
>>> something like "find /" on one text console and witch to another one -
>>> text fragments will remain on the screen on every few switches).
>>>
>>
>> Reproduces on kvm.git. I wonder what's going on.
>>
>> Looks like vesafb uses the bios to switch the display start, so I
>> expect a problem in qemu reacting to this.
>>
>
> Hm, you said it is a kernel regression. Maybe it's an issue with dirty
> bit tracking.
>

Ah, cross-posting...

It need not be a kernel thing, see my other mail.

Jan

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