From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44800) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c0wF2-00040P-G6 for qemu-devel@nongnu.org; Sun, 30 Oct 2016 15:58:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c0wEy-0005Bh-Dv for qemu-devel@nongnu.org; Sun, 30 Oct 2016 15:58:04 -0400 Date: Sun, 30 Oct 2016 22:58:11 +1100 From: David Gibson Message-ID: <20161030115811.GA21384@umbus.fritz.box> References: <1477825928-10803-1-git-send-email-david@gibson.dropbear.id.au> <1477825928-10803-18-git-send-email-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ew6BAiZeqk4r7MaW" Content-Disposition: inline In-Reply-To: <1477825928-10803-18-git-send-email-david@gibson.dropbear.id.au> Subject: Re: [Qemu-devel] [RFC 17/17] pseries: Default to POWER8 compatibility mode List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: nikunj@linux.vnet.ibm.com, aik@ozlabs.ru, mdroth@linux.vnet.ibm.com Cc: thuth@redhat.com, lvivier@redhat.com, qemu-ppc@nongnu.org, qemu-devel@nongnu.org --ew6BAiZeqk4r7MaW Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Oct 30, 2016 at 10:12:08PM +1100, David Gibson wrote: > Currently, the pseries machine defaults to running in the "raw" mode of > whatever the CPU version is - that is, without any compatibility options > enabled in the CPU. >=20 > However, migration is only really safe in "raw" mode if source and > destination have exactly the same cpu model. Since HV KVM exposes the > version of the host CPU to the guest, that means "raw" migration between > hosts with different minor revisions isn't strictly safe, although it > generally works in practice. >=20 > To allow this sort of migration in a more clearly defined way, instead > default to running in POWER8 compatibility mode - if an older CPU is used > that will automatically be downgraded to the higest available compatibili= ty > mode. >=20 > Signed-off-by: David Gibson Ugh, sorry. When I said minimally tested I did mean that it passed make check, but unfortunately I was sloppy and this last patch breaks a bunch of stuff. > --- > hw/ppc/spapr.c | 1 + > 1 file changed, 1 insertion(+) >=20 > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 2aa0900..8c18dc8 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -2194,6 +2194,7 @@ static void spapr_machine_initfn(Object *obj) > " (required for memory hot-unplug su= pport)", > NULL); > =20 > + spapr->max_compat_pvr =3D CPU_POWERPC_LOGICAL_2_07; /* POWER8 */ > object_property_add(obj, "max-cpu-compat", "str", > ppc_compat_prop_get, ppc_compat_prop_set, > NULL, &spapr->max_compat_pvr, &error_fatal); --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --ew6BAiZeqk4r7MaW Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYFeBQAAoJEGw4ysog2bOShbsP/3gN0n0VxzOiJQK7iVzG0z/U bmoF4szsZKCuulTCf+/JodLv3qISzWB5hslgSVEXg64IoRCEmfS4ewO1QQ/UuAOp qvx4uR3zu8LsIgoWGDXsYDSAG6tg663ShBI9lHi/Wly+wRTQhxLzY2vDyXVda923 cVWeg5UeEWkwD8FwAEgPqM5WaTTO/6mfGfqzYuVqukX2JjnoHI8iyS8F8ghVQTcS GnLUMm7o9xXUwC5pO3pXA3sBNMafjC8tlIIdpzKJHQIp2TiurYNS+kVl1oXWp19z TG+xcZhIElcgaF/h43GZlo8D4mIgdlVsR4dhfM1xuGBAArm+JU1tWjFgBegWP2qC walAfn2XF9GI4206xaZo2686Aooy/vx5rfAX2C3B0Hazq0qXulNlsz8+Wu1bqAag CM/u+zRTW3A6SItZhKkyOc6SZE80jZyoygLHjFbwCrZGzUuLJ9luh3VV/Dn75ZrL HQBA8bVujUyfQLX2rjq1QE/U7f4gv5KlVtyELpVyYFq8o2XTNQvHjdqg+ZKSPIZr oARTDq/bKIccrLIAUSvjPhjnCNYYAOlR20AVv8QvnrOT8GGedFhFtkNPMyEA6H56 XhK5uUc9SKUkShpRB5aT8SAr/4w5DphRLumdForyyAHpsNNttwyNcX2eXZhp0AWq LqUk/kgVVu0EeLhWabDF =pDNX -----END PGP SIGNATURE----- --ew6BAiZeqk4r7MaW--