From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dor Laor Subject: Re: virtio & hypercall interface? Date: Sat, 15 Sep 2007 01:31:52 +0300 Message-ID: <46EB0BD8.6040000@qumranet.com> References: <1189664514.32322.14.camel@localhost.localdomain> <64F9B87B6B770947A9F8391472E032160DA17EF2@ehost011-8.exch011.intermedia.net> <46E9A17D.5040205@us.ibm.com> <46EABAD0.40300@qumranet.com> Reply-To: dor.laor-atKUWr5tajBWk0Htik3J/w@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Avi Kivity Return-path: In-Reply-To: <46EABAD0.40300-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Avi Kivity wrote: > Anthony Liguori wrote: > >> Dor Laor wrote: >> >> >>>> Hi all, >>>> >>>> I've finally started looking at Dor's git tree, and it struck me >>>> >>>> >>>> >>> that >>> >>> >>> >>>> it conflicts with Anthony's hypercall patches. FWIW I like Anthony's >>>> patching thing, and don't really care about arg order. It'd be nice if >>>> we could pull in the same direction tho 8) >>>> >>>> Thanks, >>>> Rusty. >>>> >>>> >>>> >>> Good news you're looking at my tree, since the forum I didn't do much >>> since I had to catch up some gazlion other tasks, never the less >>> starting on Sunday I'm back again. >>> >>> Actually, I wanted to rebase my hypercalls over Anhtony's too (except >>> for allowing userspace handling). >>> >>> >> I thought we discussed just providing a signaling message to userspace >> for virtio? It's not strictly necessary to expose hypercalls to >> userspace in order to implement a virtio backend in userspace. >> >> >> > > Yes, that's what I'd like to see too. Signal a channel. > > First, I though that this http://www.mail-archive.com/kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org/msg06230.html was your latest opinion. Second, regardless of the channel signal notification, there are still real necessities for userspace hypercall handling: 1. For virtio drivers there is also registration hypercall for passing the shared memory pfns. Sure there are other possibilities, but why limit ourselves? 2. For other purposes such as a balloon driver, a deflate/inflate hypercalls are needed. Although for x86 mmio/pio can be used but this is not compatible with other architectures. Regards & thanks for the patch resend, Dor ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/