From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [RFC][PATCH 42/45] msix: Introduce msix_init_simple Date: Mon, 17 Oct 2011 21:21:34 +0200 Message-ID: <4E9C803E.3000702@web.de> References: <20111017112217.GC4537@redhat.com> <4E9C1123.4070204@siemens.com> <20111017142818.GG6406@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig62D0A8D7189DA7AC1079A759" Cc: Avi Kivity , Marcelo Tosatti , "kvm@vger.kernel.org" , Alex Williamson , "qemu-devel@nongnu.org" To: "Michael S. Tsirkin" Return-path: Received: from fmmailgate03.web.de ([217.72.192.234]:34706 "EHLO fmmailgate03.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754961Ab1JRLnF (ORCPT ); Tue, 18 Oct 2011 07:43:05 -0400 Received: from moweb001.kundenserver.de (moweb001.kundenserver.de [172.19.20.114]) by fmmailgate03.web.de (Postfix) with ESMTP id 7A30B1A439D73 for ; Mon, 17 Oct 2011 21:21:47 +0200 (CEST) In-Reply-To: <20111017142818.GG6406@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig62D0A8D7189DA7AC1079A759 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2011-10-17 16:28, Michael S. Tsirkin wrote: > On Mon, Oct 17, 2011 at 01:27:31PM +0200, Jan Kiszka wrote: >> On 2011-10-17 13:22, Michael S. Tsirkin wrote: >>> On Mon, Oct 17, 2011 at 11:28:16AM +0200, Jan Kiszka wrote: >>>> Devices models are usually not interested in specifying MSI-X >>>> configuration details beyond the number of vectors to provide and th= e >>>> BAR number to use. Layout of an exclusively used BAR and its >>>> registration can also be handled centrally. >>>> >>>> This is the purpose of msix_init_simple. It provides handy services = to >>>> the existing users. Future users like device assignment may require = more >>>> detailed setup specification. For them we will (re-)introduce msix_i= nit >>>> with the full list of configuration option (in contrast to the curre= nt >>>> code). >>>> >>>> Signed-off-by: Jan Kiszka >>> >>> Well, this seems a bit of a code churn then, doesn't it? >>> We are also discussing using memory BAR for virtio-pci for other >>> stuff besides MSI-X, so the last user of the _simple variant >>> will be ivshmem then? >> >> We will surely see more MSI-X users over the time. Not sure if they al= l >> mix their MSIX-X BARs with other stuff. But e.g. the e1000 variant I >> have here does not. So there should be users in the future. >> >> Jan >=20 > Question is, how hard is to pass in the BAR and the offset? That is trivial. But have a look at the final simple implementation. It also manages the container memory region for table and PBA and registers/unregisters that container as BAR. So there is measurable added-value. Jan --------------enig62D0A8D7189DA7AC1079A759 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk6cgD4ACgkQitSsb3rl5xQY4ACgoSnociX2AORIiXB3arF3iHMA tqIAoLidihNmup5bm42TD000xXU5HR+s =/IXN -----END PGP SIGNATURE----- --------------enig62D0A8D7189DA7AC1079A759--