From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eli Cohen Subject: Re: Xen interrupts when using passthrough Date: Wed, 5 Oct 2011 11:45:35 +0200 Message-ID: <20111005094535.GE2681@mtldesk30> References: <20111004162906.GA2681@mtldesk30> <4E8B3949.4090803@citrix.com> <20111004190034.GA19881@mtldesk30> <4E8C22EB0200007800059622@nat28.tlf.novell.com> <20111005082633.GC2681@mtldesk30> <4E8C369E020000780005967C@nat28.tlf.novell.com> <20111005090048.GD2681@mtldesk30> <4E8C3ACD0200007800059694@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4E8C3ACD0200007800059694@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich Cc: Andrew Cooper , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Thanks for the information. On Wed, Oct 05, 2011 at 10:09:01AM +0100, Jan Beulich wrote: > >>> On 05.10.11 at 11:00, Eli Cohen wrote: > > On Wed, Oct 05, 2011 at 09:51:10AM +0100, Jan Beulich wrote: > >> Dom0 shouldn't get involved at all - Xen does the necessary conversion. > >> Dom0 may only be involved in setting things up. Whether they get > >> received via event channels or virtual interrupts depends on the kind > >> of guest. > >> > > I think I used the wrong terminology not distinguishing between the > > hypervisor and dom0 so I will ask again just to make sure. Is the > > hypervisor involved in passing the interrupts? > > Yes, of course. The hypervisor receives all physical interrupts. > > > Does it depend on whether the guest is paravirtualized or not? > > Yes, at least to some degree. > > > The guest I am using is > > paravirtualized (i.e uses xen hypercalls), so does it mean that it > > uses event channels or is there a possibilty that it does not use > > event channels. > > Yes and no: PV guests can receive interrupts only via the event > channel mechanism. > > Jan