From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36945) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X86pB-0002od-9G for qemu-devel@nongnu.org; Fri, 18 Jul 2014 07:59:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X86p6-0007G0-AY for qemu-devel@nongnu.org; Fri, 18 Jul 2014 07:59:41 -0400 Message-ID: <53C90C20.8070400@redhat.com> Date: Fri, 18 Jul 2014 05:59:28 -0600 From: Eric Blake MIME-Version: 1.0 References: <1405657877-12353-1-git-send-email-cyrilbur@gmail.com> In-Reply-To: <1405657877-12353-1-git-send-email-cyrilbur@gmail.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="2EV8nGM6ws27mEhB3nec8BuHnuAI3Hsmh" Subject: Re: [Qemu-devel] [PATCH for-2.2] spapr: add host Linux version information to device tree List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: cyrilbur@gmail.com, qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org, Cyril Bur This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --2EV8nGM6ws27mEhB3nec8BuHnuAI3Hsmh Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 07/17/2014 10:31 PM, cyrilbur@gmail.com wrote: > It may prove useful know which Linux distribution version the host mach= ine > is running when an issue in the guest arises but a user cannot access > the host. >=20 > Signed-off-by: Cyril Bur > --- > hw/ppc/spapr.c | 8 +++++++ > target-ppc/kvm.c | 62 ++++++++++++++++++++++++++++++++++++++++++++= ++++++++ > target-ppc/kvm_ppc.h | 6 +++++ > 3 files changed, 76 insertions(+) >=20 > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 6b48a26..391d47a 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -375,6 +375,14 @@ static void *spapr_create_fdt_skel(hwaddr initrd_b= ase, > _FDT((fdt_property_string(fdt, "vm,uuid", buf))); > g_free(buf); > =20 > + /* > + * Add info to the guest FDT to tell it what linux the host is > + */ > + if (kvmppc_get_linux_host(&buf)) { > + _FDT((fdt_property_string(fdt, "linux,host", buf))); > + g_free(buf); > + } Ouch. What does this do for migration? By exposing it to the guest, you have made it part of the guest ABI, and now you have limited yourself to migrate only when the destination host is identical to the source if you don't want to risk breaking the guest. Without this, it seems feasible to migrate from a machine on an older host to another machine on a newer host. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --2EV8nGM6ws27mEhB3nec8BuHnuAI3Hsmh 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 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJTyQwgAAoJEKeha0olJ0Nq/7wH+QEzgiWR41GcrWVPV6qdL0tP EO1cW8BTWJwxV8BJB5s+bg1c08NyqSqWLlnDpXQSkJ14MROavWhVJmo4SktXHma3 bZKSkvTV4pHZEZz3kqQ8Pi13HhNFkRDVGRi3TeHg1i168qKcUbUyCt3EvxHei5gj JgL2Oe0ctHTrNd3cz19LimQ7XnA9MBrdFeNqF5hHh3BA3Ma/1yo7BBqmRLgTjcJ3 Pl4H/J89/V4nlc0HBZjtxzhKBnz5bnkqZyu2Tpg7Geg+FvvmkolYhwq+HWwpXBhN 10U/Ugg2l82ADg7dACVz4GljpejSyaeFpzfZ4qoffV+UMbd8cMYkRYm3wsVj1IQ= =CJJ6 -----END PGP SIGNATURE----- --2EV8nGM6ws27mEhB3nec8BuHnuAI3Hsmh--