Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756894AbZGGM5S (ORCPT ); Tue, 7 Jul 2009 08:57:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756039AbZGGM5C (ORCPT ); Tue, 7 Jul 2009 08:57:02 -0400 Received: from victor.provo.novell.com ([137.65.250.26]:42427 "EHLO victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755510AbZGGM5B (ORCPT ); Tue, 7 Jul 2009 08:57:01 -0400 Message-ID: <4A53460B.8090401@novell.com> Date: Tue, 07 Jul 2009 08:56:43 -0400 From: Gregory Haskins User-Agent: Thunderbird 2.0.0.22 (Macintosh/20090605) MIME-Version: 1.0 To: "Michael S. Tsirkin" CC: Avi Kivity , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Davide Libenzi Subject: Re: [KVM PATCH v9 2/2] KVM: add iosignalfd support References: <20090706202742.14222.65548.stgit@dev.haskins.net> <20090706203321.14222.67866.stgit@dev.haskins.net> <20090707112024.GA3647@redhat.com> <4A53372E.6090509@redhat.com> <20090707122250.GC3647@redhat.com> <4A533F45.90609@redhat.com> <20090707125148.GE3647@redhat.com> In-Reply-To: <20090707125148.GE3647@redhat.com> X-Enigmail-Version: 0.95.7 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig104D2BBAF622B9E48718826D" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2371 Lines: 80 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig104D2BBAF622B9E48718826D Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Michael S. Tsirkin wrote: > On Tue, Jul 07, 2009 at 03:27:49PM +0300, Avi Kivity wrote: > =20 >> On 07/07/2009 03:22 PM, Michael S. Tsirkin wrote: >> =20 >>> On Tue, Jul 07, 2009 at 02:53:18PM +0300, Avi Kivity wrote: >>> =20 >>> =20 >>>>>> + /* address-range must be precise for a hit */ >>>>>> >>>>>> =20 >>>>>> =20 >>>>> So there's apparently no way to specify that >>>>> you want 1,2, or 4 byte writes at address X? >>>>> >>>>> =20 >>>>> =20 >>>> Why would you want that? >>>> =20 >>>> =20 >>> Donnu. Why would anyone want to catch 8 byte writes at all? >>> =20 >>> =20 >> One of the natural write sizes. >> >> =20 >>> Seriously, why add artificial limitations? >>> IMO, addr=3D0,len=3D1 and addr=3D0,len=3D2 should not conflict. >>> >>> =20 >>> =20 >> They should not conflict, but a two byte write need not hit a one byte= =20 >> registration. >> =20 > > Yes. That's exactly what I'm saying. I think it should be possible to > create 2 fds: > > addr =3D 0 > len =3D 1 > addr =3D 0 > len =3D 2 > and at most one will ever trigger. > > But current code will not let you create the second one. > > =20 Note that this was by design to keep the code simple since we don't have a (known) use case for overlap. At the very least, you have to address how data subsets are handled. But do we really need that functionality? -Greg --------------enig104D2BBAF622B9E48718826D Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.11 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkpTRg8ACgkQlOSOBdgZUxlDtACeOOvy/GwWN3XqBDs1sEQFOUDs XJIAnjWGCPKk3NYs7/taJLFcmegyLkDU =oHit -----END PGP SIGNATURE----- --------------enig104D2BBAF622B9E48718826D-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/