From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH 0/3] VFIO-based PCI device assignment for QEMU 1.2 Date: Tue, 14 Aug 2012 09:19:18 +0200 Message-ID: <5029FBF6.5050600@web.de> References: <20120801050241.22163.78549.stgit@bling.home> <87pq6uvs52.fsf@codemonkey.ws> <502907EA.9030606@redhat.com> <5029097B.8050706@siemens.com> <87393qmvwe.fsf@codemonkey.ws> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig61BDF6E83AA995673FCB3A2D" Cc: Avi Kivity , Alex Williamson , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" , "aik@ozlabs.ru" , Benjamin Herrenschmidt , Cole Robinson , Alex Graf To: Anthony Liguori Return-path: Received: from mout.web.de ([212.227.17.11]:56013 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752704Ab2HNHTd (ORCPT ); Tue, 14 Aug 2012 03:19:33 -0400 In-Reply-To: <87393qmvwe.fsf@codemonkey.ws> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig61BDF6E83AA995673FCB3A2D Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2012-08-13 21:31, Anthony Liguori wrote: > Jan Kiszka writes: >=20 >> On 2012-08-13 15:58, Avi Kivity wrote: >>> On 08/13/2012 04:27 PM, Anthony Liguori wrote: >>> >>>> Thanks for pushing this forward! Hopefully this will finally kill o= ff >>>> qemu-kvm.git for good. >>> >>> No, it won't. vfio requires a 3.6 kernel, which we cannot assume any= one >>> has. We'll need the original device assignment code side-by-side. >> >> ...which is on my to-do list for 1.3. >=20 > Is there a deprecation plan for the old device assignment code? >=20 > I'm not really against the idea of requiring a new kernel for new > features. >=20 > From a Fedora/OpenSUSE point of view, would supporting old kernels be a= > requirement to stop shipping qemu-kvm.git over qemu.git? >=20 > Since distros ship new kernels and new userspaces, I don't think distro= s > would care so I'm not sure who we're trying to support old kernels for.= We are supporting KVM down to 2.6.3x, if not 2.6.2x. Also, device assignment is a new feature for upstream, but not for the masses of KVM users of QEMU (due to qemu-kvm and corresponding libvirt support). I think it will take some more kernel releases to have all feature there that allows performance-wise equivalent device assignment via VFIO. And it can even be helpful to cross-check issues of VFIO in the field. Except for some self-contained helper functions in the KVM layer, classic device assignment will be as isolated as VFIO. So I don't think we would take any noteworthy burden to maintain it as long as the kernel supports this interface. Can't comment on the other questions. Jan --------------enig61BDF6E83AA995673FCB3A2D 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/ iEYEARECAAYFAlAp+/kACgkQitSsb3rl5xSvFwCgxdWPZRg4Rb63qB9ZnH99PSrB 7QoAoKmpokOcT+W/jFUbtQCROQiF5hJ+ =EPuO -----END PGP SIGNATURE----- --------------enig61BDF6E83AA995673FCB3A2D-- From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38186) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T1BPc-0006fu-UN for qemu-devel@nongnu.org; Tue, 14 Aug 2012 03:19:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T1BPb-00089X-Qp for qemu-devel@nongnu.org; Tue, 14 Aug 2012 03:19:36 -0400 Received: from mout.web.de ([212.227.17.11]:64262) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T1BPb-00089T-GS for qemu-devel@nongnu.org; Tue, 14 Aug 2012 03:19:35 -0400 Message-ID: <5029FBF6.5050600@web.de> Date: Tue, 14 Aug 2012 09:19:18 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <20120801050241.22163.78549.stgit@bling.home> <87pq6uvs52.fsf@codemonkey.ws> <502907EA.9030606@redhat.com> <5029097B.8050706@siemens.com> <87393qmvwe.fsf@codemonkey.ws> In-Reply-To: <87393qmvwe.fsf@codemonkey.ws> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig61BDF6E83AA995673FCB3A2D" Subject: Re: [Qemu-devel] [PATCH 0/3] VFIO-based PCI device assignment for QEMU 1.2 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: "kvm@vger.kernel.org" , "aik@ozlabs.ru" , "qemu-devel@nongnu.org" , Alex Graf , Alex Williamson , Avi Kivity , Cole Robinson This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig61BDF6E83AA995673FCB3A2D Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2012-08-13 21:31, Anthony Liguori wrote: > Jan Kiszka writes: >=20 >> On 2012-08-13 15:58, Avi Kivity wrote: >>> On 08/13/2012 04:27 PM, Anthony Liguori wrote: >>> >>>> Thanks for pushing this forward! Hopefully this will finally kill o= ff >>>> qemu-kvm.git for good. >>> >>> No, it won't. vfio requires a 3.6 kernel, which we cannot assume any= one >>> has. We'll need the original device assignment code side-by-side. >> >> ...which is on my to-do list for 1.3. >=20 > Is there a deprecation plan for the old device assignment code? >=20 > I'm not really against the idea of requiring a new kernel for new > features. >=20 > From a Fedora/OpenSUSE point of view, would supporting old kernels be a= > requirement to stop shipping qemu-kvm.git over qemu.git? >=20 > Since distros ship new kernels and new userspaces, I don't think distro= s > would care so I'm not sure who we're trying to support old kernels for.= We are supporting KVM down to 2.6.3x, if not 2.6.2x. Also, device assignment is a new feature for upstream, but not for the masses of KVM users of QEMU (due to qemu-kvm and corresponding libvirt support). I think it will take some more kernel releases to have all feature there that allows performance-wise equivalent device assignment via VFIO. And it can even be helpful to cross-check issues of VFIO in the field. Except for some self-contained helper functions in the KVM layer, classic device assignment will be as isolated as VFIO. So I don't think we would take any noteworthy burden to maintain it as long as the kernel supports this interface. Can't comment on the other questions. Jan --------------enig61BDF6E83AA995673FCB3A2D 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/ iEYEARECAAYFAlAp+/kACgkQitSsb3rl5xSvFwCgxdWPZRg4Rb63qB9ZnH99PSrB 7QoAoKmpokOcT+W/jFUbtQCROQiF5hJ+ =EPuO -----END PGP SIGNATURE----- --------------enig61BDF6E83AA995673FCB3A2D--