Re: [Qemu-devel] [PATCH v5] xen_console: support the new extended xenstore protocol

[Stefano Stabellini]

On Mon, 4 Jul 2011, Alexander Graf wrote:
> 
> On 30.06.2011, at 19:26, <address@hidden> <address@hidden> wrote:
> 
> > From: Stefano Stabellini <address@hidden>
> > 
> > Since CS 21994 on xen-unstable.hg and CS
> > 466608f3a32e1f9808acdf832a5843af37e5fcec on qemu-xen-unstable.git, few
> > changes have been introduced to the PV console xenstore protocol, as
> > described by the document docs/misc/console.txt under xen-unstable.hg.
> > 
> > From the Qemu point of view, very few modifications are needed to
> > correctly support the protocol: read from xenstore the "output" node
> > that tell us what the output of the PV console is going to be.
> > In case the output is a tty, write to xenstore the device name.
> 
> This one breaks my usual smoke test case of executing a Xen PV machine:
> 
>   $ ./x86_64-softmmu/qemu-system-x86_64 -xen-create -xen-domid 2 -M xenpv 
> -kernel /boot/vmlinux-xen -initrd /boot/initrd-xen -append 'xencons=tty 
> root=/dev/null' -nographic
> 
> How about this patch on top? That way you can still override Qemu's serial 
> choice with xenstore, but keep the Qemu infrastructure in place for people 
> who don't want to use it. This will be especially important when Xenner comes 
> around, where a Xen PV VM feels the same as any other Qemu machine.
> 

I think it is a reasonable compromise.