Re: [Qemu-devel] Qemu speed vs vmplayer?

[Lonnie Mendez <lmendez19@austin.rr.com>]

On Fri, 2006-12-15 at 17:20 -0500, Joseph Miller wrote:  
> I've got a copy of today's CVS, I was just assuming, since this is the 
> qemu-devel mailing list, that someone on the list who regularly works on 
> the qemu code would probably know more about this than I do.  I have 
> some assembly background, and I'm not afraid to start digging into x86 
> cpu internals, but I would like a starting point.  I'm really trying to 
> figure out something specific about qemu.  When running Qemu+KQEMU for 
> linux-x86 host on WinXP x86 guest, top shows that 70% or more of my cpu 
> is being use in the system portion.  When using vmplayer (free), top 
> shows less than 5% of my cpu in the system portion.  vmplayer seems to 
> be a LOT faster than Qemu, however I would prefer to use Qemu.  I have a 
> P4 2.6GHz host system with 1.5G RAM and 512MB RAM allocated to my guest 
> OS's.  Does anyone know the reason behind the slowdown?  Is anyone 
> familiar with what Qemu is so busy doing whilst sitting idle?  I should 
> note that I have compiled the KQemu into my 2.6 kernel instead of 
> loading it as a module.  I have found better performance with it this 
> way.  Any insight from a developer would be most appreciated.

Are you using the -kernel-kqemu switch?  I see idle usage of 6-10% with
kqemu using -kernel-kqemu on windows xp guest.  kqemu is closed source
software.  If you want a starting point for improving the acceleration
portion then start by improving qvm86 (the GPL'ed accelerator).