From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anthony Liguori <anthony@codemonkey.ws>
Subject: Re: KVM usability
Date: Mon, 01 Mar 2010 09:36:04 -0600
Message-ID: <4B8BDEE4.2050104@codemonkey.ws>
References: <1267089644.12790.74.camel@laptop> <1267152599.1726.76.camel@localhost> <20100226090147.GH15885@elte.hu> <4B879A2F.50203@redhat.com> <20100226103545.GA7463@elte.hu> <4B87A6BF.3090301@redhat.com> <20100226111734.GE7463@elte.hu> <4B8813F2.8090208@redhat.com> <20100227105643.GA17425@elte.hu> <4B893B2B.40301@redhat.com> <20100301092515.GA3163@elte.hu>
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Cc: Zachary Amsden <zamsden@redhat.com>, Avi Kivity <avi@redhat.com>,
	"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>, ming.m.lin@intel.com,
	sheng.yang@intel.com, Jes Sorensen <Jes.Sorensen@redhat.com>,
	KVM General <kvm@vger.kernel.org>,
	Gleb Natapov <gleb@redhat.com>,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	Fr??d??ric Weisbecker <fweisbec@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Arjan van de Ven <arjan@infradead.org>
To: Ingo Molnar <mingo@elte.hu>
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On 03/01/2010 03:25 AM, Ingo Molnar wrote:
> * Zachary Amsden<zamsden@redhat.com>  wrote:
>
>    
>>> Here's my experience with it:
>>>
>>>   - qemu-kvm starts up with a miniature resolution by default. 640x480 - on my
>>>     1680x1050 laptop screen. It's so small that initially i even overlooked
>>>     that i started it. It should multiplex pixels up to a reasonable screen
>>>     size by default.
>>>        
>> No virtualization emulator today does this, it is not a reasonable thing to
>> do.  Unless you are running compiz and use hardware scaling.  We should look
>> into it.
>>      
> I tried VirtualBox and it does something sane here: while it does not give a
> larger guest screen area, it at least creates a large enough X window, with
> any border area whited out.
>
> That looks far more pleasing aesthetically than the Qemu method of resizing
> the full window wildly. The guest still resizes, but it stays within the same
> X window and the border is white.
>
> Also, with Windows guests, the Windows side resolution resizes dynamically if
> the window is grown/shrunk by the user. (I suspect that is done via a paravirt
> driver on the guest side, through 'Guest Additions'.)
>    

We have to core pieces to do this in qemu.  The vmware vga driver 
supports this and it just takes a small userspace program to resize the 
VGA on demand.

The problem is, you need a way to communicate from the host to the 
guest's userspace.  We did not have a mechanism until very recently 
(virtio-serial) because we've encountered a ton of resistance within the 
kernel community for the things we've proposed.

VirtualBox gets around this by just shipping their own Linux drivers.

Regards,

Anthony Liguori

> 	Ingo
>