Re: [Qemu-devel] QEMU fw_cfg DMA interface

[Kevin O'Connor]

On Thu, Aug 06, 2015 at 02:37:45PM +0200, Marc Marí wrote:
> On Thu, 6 Aug 2015 13:27:16 +0100
> Stefan Hajnoczi <address@hidden> wrote:
> 
> > On Thu, Aug 6, 2015 at 12:00 PM, Marc Marí <address@hidden> wrote:
> > > When running a Linux guest on top of QEMU, using the -kernel
> > > options, this is the timing improvement for x86:
> > >
> > > QEMU commit 2be4f242b50a8 and SeaBIOS commit 908a58c1d5ff
> > > QEMU startup time: .078
> > > BIOS startup time: .060
> > > Kernel setup time: .578
> > > Total time: .716
> > >
> > > QEMU with this patch series and SeaBIOS with this patch series
> > > QEMU startup time: .080
> > > BIOS startup time: .039
> > > Kernel setup time: .002
> > > Total time: .121
> > 
> > Impressive results!
> > 
> > Is this a fully-featured QEMU build or did you disable things?
> > 
> > Is this the default SeaBIOS build or did you disable things?
> > 
> 
> This is the default QEMU configuration I get for my system. It's not a
> fully-featured QEMU, but it has a lot of things enabled. SeaBIOS
> has a default configuration (with debugging disabled).

Thanks!

What qemu command-line did you use during testing?  Also, do you have
a quick primer on how to use the kvm trace stuff to obtain timings?

-Kevin