From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33970) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bLOP4-0002Yj-6V for qemu-devel@nongnu.org; Fri, 08 Jul 2016 01:32:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bLOP1-0007RW-R4 for qemu-devel@nongnu.org; Fri, 08 Jul 2016 01:32:41 -0400 Date: Fri, 8 Jul 2016 15:21:18 +1000 From: David Gibson Message-ID: <20160708052118.GL14675@voom.fritz.box> References: <1467903025-13383-1-git-send-email-bharata@linux.vnet.ibm.com> <1467903025-13383-3-git-send-email-bharata@linux.vnet.ibm.com> <20160707195232.6347b8ed@bahia.lan> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="J/pvEKOcHgREgBce" Content-Disposition: inline In-Reply-To: <20160707195232.6347b8ed@bahia.lan> Subject: Re: [Qemu-devel] [RFC PATCH v2 2/5] cpu: Introduce CPUState::stable_cpu_id List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Greg Kurz Cc: Bharata B Rao , qemu-devel@nongnu.org, qemu-ppc@nongnu.org, imammedo@redhat.com, nikunj@linux.vnet.ibm.com, pbonzini@redhat.com --J/pvEKOcHgREgBce Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 07, 2016 at 07:52:32PM +0200, Greg Kurz wrote: > On Thu, 7 Jul 2016 20:20:22 +0530 > Bharata B Rao wrote: >=20 > > Add CPUState::stable_cpu_id and use that as instance_id in > > vmstate_register() call. > >=20 > > Introduce has-stable_cpu_id property that allows target machines to > > optionally switch to using stable_cpu_id instead of cpu_index. >=20 > If stable_cpu_id is in the [0..max_vcpus) range, then it does not really = depend > on the machine type or version. No.. it really does. The ids need to exactly match, not just be in the same range in order to maintain migration compatibility with pre-stable_cpu_id versions of qemu. > In this case, the property is not needed. >=20 > > This will help allow successful migration in cases where holes are > > introduced in cpu_index range after CPU hot removals. > >=20 > > Suggested-by: Igor Mammedov > > Signed-off-by: Bharata B Rao > > --- > > exec.c | 6 ++++-- > > include/qom/cpu.h | 5 +++++ > > qom/cpu.c | 6 ++++++ > > 3 files changed, 15 insertions(+), 2 deletions(-) > >=20 > > diff --git a/exec.c b/exec.c > > index fb73910..3b36fe5 100644 > > --- a/exec.c > > +++ b/exec.c > > @@ -619,12 +619,14 @@ static void cpu_release_index(CPUState *cpu) > > void cpu_vmstate_register(CPUState *cpu) > > { > > CPUClass *cc =3D CPU_GET_CLASS(cpu); > > + int instance_id =3D cpu->has_stable_cpu_id ? cpu->stable_cpu_id : > > + cpu->cpu_index; > > =20 > > if (qdev_get_vmsd(DEVICE(cpu)) =3D=3D NULL) { > > - vmstate_register(NULL, cpu->cpu_index, &vmstate_cpu_common, cp= u); > > + vmstate_register(NULL, instance_id, &vmstate_cpu_common, cpu); > > } > > if (cc->vmsd !=3D NULL) { > > - vmstate_register(NULL, cpu->cpu_index, cc->vmsd, cpu); > > + vmstate_register(NULL, instance_id, cc->vmsd, cpu); > > } > > } > > =20 > > diff --git a/include/qom/cpu.h b/include/qom/cpu.h > > index 331386f..527c021 100644 > > --- a/include/qom/cpu.h > > +++ b/include/qom/cpu.h > > @@ -273,6 +273,9 @@ struct qemu_work_item { > > * @kvm_fd: vCPU file descriptor for KVM. > > * @work_mutex: Lock to prevent multiple access to queued_work_*. > > * @queued_work_first: First asynchronous work pending. > > + * @stable_cpu_id: Use as instance_id argument in cpu vmstate_register= calls > > + * @has_stable_cpu_id: Set to enforce the use of @stable_cpu_id > > + * over cpu_index during vmstate registration. > > * > > * State of one CPU core or thread. > > */ > > @@ -360,6 +363,8 @@ struct CPUState { > > (absolute value) offset as small as possible. This reduces code > > size, especially for hosts without large memory offsets. */ > > uint32_t tcg_exit_req; > > + int stable_cpu_id; > > + bool has_stable_cpu_id; > > }; > > =20 > > QTAILQ_HEAD(CPUTailQ, CPUState); > > diff --git a/qom/cpu.c b/qom/cpu.c > > index 1095ea1..bae1bf7 100644 > > --- a/qom/cpu.c > > +++ b/qom/cpu.c > > @@ -363,6 +363,11 @@ static int64_t cpu_common_get_arch_id(CPUState *cp= u) > > return cpu->cpu_index; > > } > > =20 > > +static Property cpu_common_properties[] =3D { > > + DEFINE_PROP_BOOL("has-stable-cpu-id", CPUState, has_stable_cpu_id,= false), > > + DEFINE_PROP_END_OF_LIST() > > +}; > > + > > static void cpu_class_init(ObjectClass *klass, void *data) > > { > > DeviceClass *dc =3D DEVICE_CLASS(klass); > > @@ -394,6 +399,7 @@ static void cpu_class_init(ObjectClass *klass, void= *data) > > * IRQs, adding reset handlers, halting non-first CPUs, ... > > */ > > dc->cannot_instantiate_with_device_add_yet =3D true; > > + dc->props =3D cpu_common_properties; > > } > > =20 > > static const TypeInfo cpu_type_info =3D { >=20 --=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 --J/pvEKOcHgREgBce Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJXfzhOAAoJEGw4ysog2bOSZVoQAMN4YRApDeIuckc7Ezimq695 buXX8zPY3xv9pPz/+rOVotp1g01wvj7s3mkTK/QI2FhJOmFi3bsRyeV7uS89vVQj w+oWQEBPI6IxpmmrGL15d5FJD4eggjXRTT9a+DvFO6aQOGfG4IVuKDlFCuaJDBMZ 1LC2ptqbMAPk7euoTPho/dSKOKL2bi5hPJ+iZsETUQA7FkqDJtUKFHvl5MR+AyfM 4r9GeEGafbFobR1DU3oX6WNGefyzpfuvrLZDTtI6NYziQCASPKWojHr3SVUqD1Zd L4SqWUneyc6ggA0gjZw3zlCB4FQQcclZ0Rxm6N21AgOx0T7vxQDnrENpSydkbVfV kgG77Y8hswOUFunl5ildII/VG0VslCNcNk9zKLoyh0MnGWMSfg5xdLiJ6tAmsmlw O0l8E2gl/di9VneP5hb/u0BMXRxHW10fRVwrql2NQtv8eZob4ump1Rf0/OV1F6mJ LLAWNaR02+OalKcxYd67B0su3fRSKW5pdXdEVm0qedT3FVekRvqNI5+v3OjJmjsn wBEj9eKTR0dvbTyF79IEhthHHIIopxbBPe9ZqiWvuCz4GPuqtG8nqOACBQtMjkbI 9w7XuKRBfg6RCSWPmLYnUcYUfNxnPoZpyS7cXqW+483izLlT3Yjc3biuTlZxe+sx vVd1IHaxha6qpLKySGYb =bHlR -----END PGP SIGNATURE----- --J/pvEKOcHgREgBce--