Re: [Qemu-devel] Anyone seeing huge slowdown launching qemu with Linux 2.6.35?

[Gleb Natapov]

On Tue, Aug 03, 2010 at 09:43:39PM +0300, Avi Kivity wrote:
> >
> >If Richard is willing to do the work to make -kernel perform
> >faster in such a way that it fits into the overall mission of what
> >we're building, then I see no reason to reject it.  The criteria
> >for evaluating a patch should only depend on how it affects other
> >areas of qemu and whether it impacts overall usability.
> 
> That's true, but extending fwcfg doesn't fit into the overall
> picture well.  We have well defined interfaces for pushing data into
> a guest: virtio-serial (dma upload), virtio-blk (adds demand
> paging), and virtio-p9fs (no image needed).  Adapting libguestfs to
> use one of these is a better move than adding yet another interface.
> 
+1. I already proposed that. Nobody objects against fast fast
communication channel between guest and host. In fact we have one:
virtio-serial. Of course it is much easier to hack dma semantic into
fw_cfg interface than add virtio-serial to seabios, but it doesn't make
it right. Does virtio-serial has to be exposed as PCI to a guest or can
we expose it as ISA device too in case someone want to use -kernel option
but do not see additional PCI device in a guest?

--
                        Gleb.