From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: RFC Userspace hypercalls
Date: Wed, 6 Jan 2016 16:38:10 +0000
Message-ID: <568D42F2.6070900@citrix.com>
References: <568CFE3A.8080505@citrix.com>
	<568D2F4002000078000C3F7E@prv-mh.provo.novell.com>
	<568D2860.3010807@citrix.com>
	<568D4F6502000078000C418C@prv-mh.provo.novell.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <568D4F6502000078000C418C@prv-mh.provo.novell.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Jan Beulich <JBeulich@suse.com>
Cc: Tim Deegan <tim@xen.org>, Keir Fraser <keir@xen.org>, Xen-devel List <xen-devel@lists.xen.org>
List-Id: xen-devel@lists.xenproject.org

On 06/01/16 16:31, Jan Beulich wrote:
>>>> On 06.01.16 at 15:44, <andrew.cooper3@citrix.com> wrote:
>> We did have an internal request for an HVM guest userspace netfront
>> driver to be able to use evntchnop calls directly.
> And this can't be accomplished using the evtchn and/or privcmd
> drivers?

It can, and I don't believe the worry about extra overhead is well
placed.  (There many areas of lower hanging fruit in this specific case).

However, a userspace backend isn't in principle a bad idea.

~Andrew