Re: [Qemu-devel] [PATCH v2 0/3] kvm:showing a splash picture when start

[Wayne Xia <xiawenc@linux.vnet.ibm.com>]

  2011-6-23 20:29, Jan Kiszka :
> On 2011-06-23 14:05, Daniel P. Berrange wrote:
>> On Thu, Jun 23, 2011 at 01:24:01PM +0200, Jan Kiszka wrote:
>>> On 2011-06-23 13:20, Wayne Xia wrote:
>>>> 2011-6-23 18:03, Jan Kiszka
>>>>> On 2011-06-23 11:18, Wayne Xia wrote:
>>>>>> Hi,
>>>>>>       these 3 patch simply enable qemu-kvm to show a logo picture when it
>>>>>
>>>>> You are posting on qemu-devel (which is correct for this topic), so your
>>>>> patches must target that tree. Patch 1 eg. does not and needs rebasing.
>>>>>
>>>> thanks for the tip.
>>>>>> s start up, following is how to configurate it:
>>>>>>       invoke it with params:
>>>>>>       -boot (splash_time=<N>,) (splash_filename=<N>,)
>>>>>
>>>>> Simply 'splash' for specifying the file should suffice.
>>>>>
>>>>>>       the splash_time is in the unit of ms, and its max value is 65535.
>>>>>> this feature is by default on with 5000ms showing up.
>>>>>
>>>>> Strong NAK for making this default. We have a nice sub-second BIOS time
>>>>> in QEMU, and that must not be destroyed by eye candy. 5 s is also way
>>>>> too long even when you want splash.
>>>>>
>>>> Maybe 5 is a bit too long, this patch is for test so made it a bit
>>>> longer to be observed by VNC, I think 2.5s would be fit.
>>>
>>> Maybe it could be something like that if the user specifies a splash
>>> file - which indicates that there should be some splash delay as well.
>>> Default without any splash parameter must remain 0, ie. disabled.
>>
>> I don't think you want to change default timeouts based on whether
>> a splash screen is present. Consider that if you have enabled PXE boot
>> on one of the guest NICs, then there is already a few second delay
>> while the BIOS PXEs, during which it QEMU would be showing the splash
>> screen. You don't then want to add a further 2.5s or 5s delay ontop
>> of that already imposed by the BIOS PXE process. Just let the splash
>> screen be displayed for however long the BIOS process takes, without
>> any extra artifical delays, even if this is a mere fraction of a
>> second in some cases.
>
> I don't want the splash to show up at all by default, even just for a
> fraction of a second. Already loading that image costs time
> (specifically as it's squeezed into fwcfg), and that would be unacceptable.
>
> My point is that, if the user specifies "-boot
> splash=my-nice-splace.bmp", there is likely the wish to see the result
> more than a few 100 ms. Again, that's the case where the user asked for
> a slowdown anyway.
>
    Completely understand that in most cases the Qemu-kvm should boot up
as soon as it can. Making this default now is just to provide a
convenient way to test it temporarily, I did that to make it easily
tested in the GUI--Virtual Machine Manager which would not accept
additional parameters to enable the splash screen. Sorry for having not
explained it clearly.
    I agree that if the user specifies it, then this logo would be
shown.

> Jan
>


-- 
Best Regards

Wayne Xia
mail:xiawenc@linux.vnet.ibm.com
tel:86-010-82450803