From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Blake Subject: Re: [QEMU 1.1 PATCH v2] Expose CPUID leaf 7 only for -cpu host Date: Thu, 17 May 2012 10:56:36 -0600 Message-ID: <4FB52DC4.5040609@redhat.com> References: <20120517162655.GQ16951@otherpad.lan.raisama.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enig3361FDC644A9D89B481C9CB5" Cc: kvm@vger.kernel.org, Marcelo Tosatti , qemu-devel@nongnu.org, Gleb Natapov , Avi Kivity To: Eduardo Habkost Return-path: In-Reply-To: <20120517162655.GQ16951@otherpad.lan.raisama.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig3361FDC644A9D89B481C9CB5 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 05/17/2012 10:26 AM, Eduardo Habkost wrote: > The problem is that this makes the resulting CPU feature flags > unpredictable and dependent on the host CPU and kernel version. This > breaks live-migration badly if migrating from a host CPU that supports > some features on that CPUID leaf (running a recent kenrel) to a kernel s/kenrel/kernel/ --=20 Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --------------enig3361FDC644A9D89B481C9CB5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBCAAGBQJPtS3FAAoJEKeha0olJ0NqThQIAI5w4oDEdpq0nlPdrwvdTqBg nG5QlSlYtwRaJKwm+Nw1E6NRCre0eIZa3H75ttlr1+RBjiUJ/CikOfMx9SJNADyg uHEu9QG/LtNqHEusrUpn3aVGw8BOSjXhsDL4PZWrtM3maVGdF48Ky2yjqCj0O5Gd IHQ2dnp3iPnCsZGbDFCLVz8IB9VZxXky2++Vpe3YbKYaLP58YQpqo8BLm+iKt+sT U0U+b6nnCGTFXoD9p76Yii0ssQiMrbxLnvoO3R2fsXpef9Yhw5xAh9dMivaszAy1 rd4IYOJj9eFh2G+0AUSFWeFWVKi9RWYtPfiTgn0FSIixn58vU7LwtTgnVtolWo0= =UBhM -----END PGP SIGNATURE----- --------------enig3361FDC644A9D89B481C9CB5-- From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41306) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SV40J-0007VN-0E for qemu-devel@nongnu.org; Thu, 17 May 2012 12:56:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SV40H-0005To-9m for qemu-devel@nongnu.org; Thu, 17 May 2012 12:56:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56336) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SV40H-0005Te-1a for qemu-devel@nongnu.org; Thu, 17 May 2012 12:56:41 -0400 Message-ID: <4FB52DC4.5040609@redhat.com> Date: Thu, 17 May 2012 10:56:36 -0600 From: Eric Blake MIME-Version: 1.0 References: <20120517162655.GQ16951@otherpad.lan.raisama.net> In-Reply-To: <20120517162655.GQ16951@otherpad.lan.raisama.net> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enig3361FDC644A9D89B481C9CB5" Subject: Re: [Qemu-devel] [QEMU 1.1 PATCH v2] Expose CPUID leaf 7 only for -cpu host List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: kvm@vger.kernel.org, Marcelo Tosatti , qemu-devel@nongnu.org, Gleb Natapov , Avi Kivity This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig3361FDC644A9D89B481C9CB5 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 05/17/2012 10:26 AM, Eduardo Habkost wrote: > The problem is that this makes the resulting CPU feature flags > unpredictable and dependent on the host CPU and kernel version. This > breaks live-migration badly if migrating from a host CPU that supports > some features on that CPUID leaf (running a recent kenrel) to a kernel s/kenrel/kernel/ --=20 Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --------------enig3361FDC644A9D89B481C9CB5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBCAAGBQJPtS3FAAoJEKeha0olJ0NqThQIAI5w4oDEdpq0nlPdrwvdTqBg nG5QlSlYtwRaJKwm+Nw1E6NRCre0eIZa3H75ttlr1+RBjiUJ/CikOfMx9SJNADyg uHEu9QG/LtNqHEusrUpn3aVGw8BOSjXhsDL4PZWrtM3maVGdF48Ky2yjqCj0O5Gd IHQ2dnp3iPnCsZGbDFCLVz8IB9VZxXky2++Vpe3YbKYaLP58YQpqo8BLm+iKt+sT U0U+b6nnCGTFXoD9p76Yii0ssQiMrbxLnvoO3R2fsXpef9Yhw5xAh9dMivaszAy1 rd4IYOJj9eFh2G+0AUSFWeFWVKi9RWYtPfiTgn0FSIixn58vU7LwtTgnVtolWo0= =UBhM -----END PGP SIGNATURE----- --------------enig3361FDC644A9D89B481C9CB5--