Re: [Xen-devel] Fwd: Question about Xen Console

[Wei Xu <wei.xu.prc@xxxxxxxxx>]

On Mon, Apr 1, 2013 at 8:47 PM, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> wrote:

On Mon, Apr 01, 2013 at 01:59:15PM +0800, Wei Xu wrote:
> Hi Konrad,
> I'd like to consult you some questions about the Xen Console, i'm
> investigating it recently, i take some test on Linux(Fedora) hvm guest, it
> works good. (Xen-4.1.3 and Linux 3.5.0).
>
> The most confused question of me is why did Xen Console come to mind in the
> early date, What's the requirement? Was it going to replace the emulated
> serial by qemu, or just an additional way to access the guest with high
> performance or sth other?
>
> I have post this in the xen-devel mail list and got some useful answer,

Then lets add CC to it again.

> since you are the expert about it, I'd like to consult you for the original
> answer, thanks.

The answer is 'additional way to access the guest without having to emulate
the serial port'

Thanks.

So this will improve the performance a lot on both Dom0 and DomU side, since the speed is not very critical when accessing a guest via console, I guess the most important benefit is to reduce the cpu cost of dom0  when emulating the serial port, is it or sth other?

I have talked to stefano and he told the early printk is not supported by HVM guest while it's available for PV guest with "earlyprintk=xen" indicated in kernel boot up parameters, so is there any concern to support it in the future? or is this worth to do?

> Regards,

> Wei

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel