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Re: [Xen-devel] use xs_watch from userspace and use epoll instead of sel

On Mon, 2011-06-06 at 09:58 +0100, Vasiliy G Tolstov wrote:
> Code to using from domU. I'm correct all my mistakes and now relative
> and full path watches work's fine with epoll and select based looping.
> Sorry for wrong panic about it. 

Oh good.

> Sorry for small offtop, where i can find example to use grand pages to
> transfer for example 1byte from domU to dom) and vice versa?

(it's "grant" pages).

Any of the PV drivers would give a decent example for in kernel use of
grant tables to setup a shared memory buffer, but I guess you are asking
for a userspace example? The principals are mostly the same, except you
use xc_* functions instead of the kernel ones.

qemu contains some userspace backends, for example the xenfb backend.
Daniel de Graaf posted some patches to make this use grant tables back
in February/March this year -- you should check the ML archives. There
are also PV disk and net backends in qemu.

I can't think of any userspace frontends offhand.

Once you have a shared page you can use the standard Xen ring.h
datastructures to define your request and response protocol.

What are you actually trying to build?


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