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Violators will be prosecuted for from ; Thu, 7 Jul 2016 00:18:12 +1000 Date: Wed, 6 Jul 2016 19:48:03 +0530 From: Bharata B Rao Reply-To: bharata@linux.vnet.ibm.com References: <1467795561-1007-1-git-send-email-bharata@linux.vnet.ibm.com> <1467795561-1007-3-git-send-email-bharata@linux.vnet.ibm.com> <20160706133459.1a123a6f@172-15-179-184.lightspeed.austtx.sbcglobal.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160706133459.1a123a6f@172-15-179-184.lightspeed.austtx.sbcglobal.net> Message-Id: <20160706141803.GF25522@in.ibm.com> Subject: Re: [Qemu-devel] [RFC PATCH v1 2/5] cpu: Introduce CPUState::migration_id List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: qemu-devel@nongnu.org, qemu-ppc@nongnu.org, david@gibson.dropbear.id.au, groug@kaod.org, nikunj@linux.vnet.ibm.com, pbonzini@redhat.com On Wed, Jul 06, 2016 at 01:34:59PM +0200, Igor Mammedov wrote: > On Wed, 6 Jul 2016 14:29:18 +0530 > Bharata B Rao wrote: > > > Add CPUState::migration_id and use that as instance_id in > > vmstate_register() call. > > > > Introduce use-migration-id property that allows target machines to > > optionally switch to using migration_id instead of cpu_index. > > This will help allow successful migration in cases where holes are > > introduced in cpu_index range after CPU hot removals. > > > > The default implementation of CPUClass:get_migration_id() continues > > to return cpu_index. > > > > Suggested-by: Igor Mammedov > > Signed-off-by: Bharata B Rao > > --- > > exec.c | 5 +++-- > > include/qom/cpu.h | 6 ++++++ > > qom/cpu.c | 21 +++++++++++++++++++++ > > 3 files changed, 30 insertions(+), 2 deletions(-) > > > > diff --git a/exec.c b/exec.c > > index fb73910..a8afeda 100644 > > --- a/exec.c > > +++ b/exec.c > > @@ -619,12 +619,13 @@ static void cpu_release_index(CPUState *cpu) > > void cpu_vmstate_register(CPUState *cpu) > > { > > CPUClass *cc = CPU_GET_CLASS(cpu); > > + int instance_id = cc->get_migration_id(cpu); > > > > if (qdev_get_vmsd(DEVICE(cpu)) == NULL) { > > - vmstate_register(NULL, cpu->cpu_index, &vmstate_cpu_common, > > cpu); > > + vmstate_register(NULL, instance_id, &vmstate_cpu_common, > > cpu); } > > if (cc->vmsd != NULL) { > > - vmstate_register(NULL, cpu->cpu_index, cc->vmsd, cpu); > > + vmstate_register(NULL, instance_id, cc->vmsd, cpu); > > } > > } > > > > diff --git a/include/qom/cpu.h b/include/qom/cpu.h > > index 29ccf5c..6d00143 100644 > > --- a/include/qom/cpu.h > > +++ b/include/qom/cpu.h > > @@ -187,6 +187,7 @@ typedef struct CPUClass { > > bool (*cpu_exec_interrupt)(CPUState *cpu, int interrupt_request); > > > > void (*disas_set_info)(CPUState *cpu, disassemble_info *info); > > + int (*get_migration_id)(CPUState *cpu); > > } CPUClass; > > > > #ifdef HOST_WORDS_BIGENDIAN > > @@ -273,6 +274,9 @@ 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. > > + * @migration_id: Use as instance_id argument in cpu > > vmstate_register calls > with this field get_migration_id() callback is redundant. > You can drop get_migration_id() and assign value to migration_id in > machine specific code /spapr/ppc/x86/.../ before realize is called. > That should simplify this patch and its users as well. Let me give that a try and see how it looks. > > > + * @use_migration_id: Set to enforce the use of > > CPUClass.get_migration_id() > > + * over cpu_index during vmstate registration. > > * > > * State of one CPU core or thread. > > */ > > @@ -360,6 +364,8 @@ 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 migration_id; > > + bool use_migration_id; > > }; > > > > QTAILQ_HEAD(CPUTailQ, CPUState); > > diff --git a/qom/cpu.c b/qom/cpu.c > > index 488ecc6..01cf136 100644 > > --- a/qom/cpu.c > > +++ b/qom/cpu.c > > @@ -326,6 +326,17 @@ static void cpu_common_realizefn(DeviceState > > *dev, Error **errp) } > > } > > > > +static bool cpu_common_get_use_migration_id(Object *obj, Error > > **errp) +{ > > + return CPU(obj)->use_migration_id; > > +} > > + > > +static void cpu_common_set_use_migration_id(Object *obj, bool value, > > + Error **err) > > +{ > > + CPU(obj)->use_migration_id = value; > > +} > It's possible to create dumb property in a more compact way, > see DEFINE_PROP_BOOL() I stated with it and defined dc->props, but then felt it is a bit too much to define a list just for one property. But if that preferable let me switch back to it. Regards, Bharata.