diff mbox

[RFC,1/2] qapi: Add vcpu id to query-hotpluggable-cpus output

Message ID 59c8f2c8e80d705fb4981bddd9fe703c1205346c.1467904342.git.pkrempa@redhat.com
State New
Headers show

Commit Message

Peter Krempa July 7, 2016, 3:17 p.m. UTC
Add 'vcpu index' to the output of query hotpluggable cpus. This output
is identical to the linear cpu index taken by the 'cpus' attribute
passed to -numa.

This will allow to reliably map the cpu number to a given topology
element without making mgmt apps to reimplement the mapping.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
---
 hmp.c            | 1 +
 hw/i386/pc.c     | 1 +
 hw/ppc/spapr.c   | 1 +
 qapi-schema.json | 2 ++
 4 files changed, 5 insertions(+)

Comments

David Gibson July 8, 2016, 2:18 a.m. UTC | #1
On Thu,  7 Jul 2016 17:17:13 +0200
Peter Krempa <pkrempa@redhat.com> wrote:

> Add 'vcpu index' to the output of query hotpluggable cpus. This output
> is identical to the linear cpu index taken by the 'cpus' attribute
> passed to -numa.


The problem is, the vcpu index of what?  Each entry in the hotpluggable
cpus table could represent more than one vcpu.

> This will allow to reliably map the cpu number to a given topology
> element without making mgmt apps to reimplement the mapping.
> 
> Signed-off-by: Peter Krempa <pkrempa@redhat.com>
> ---
>  hmp.c            | 1 +
>  hw/i386/pc.c     | 1 +
>  hw/ppc/spapr.c   | 1 +
>  qapi-schema.json | 2 ++
>  4 files changed, 5 insertions(+)
> 
> diff --git a/hmp.c b/hmp.c
> index 0cf5baa..613601e 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -2450,6 +2450,7 @@ void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
>          monitor_printf(mon, "  type: \"%s\"\n", l->value->type);
>          monitor_printf(mon, "  vcpus_count: \"%" PRIu64 "\"\n",
>                         l->value->vcpus_count);
> +        monitor_printf(mon, "  vcpu_id: \"%" PRIu64 "\"\n", l->value->vcpu_id);
>          if (l->value->has_qom_path) {
>              monitor_printf(mon, "  qom_path: \"%s\"\n", l->value->qom_path);
>          }
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index f293a0c..4ba02c4 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -2131,6 +2131,7 @@ static HotpluggableCPUList *pc_query_hotpluggable_cpus(MachineState *machine)
> 
>          cpu_item->type = g_strdup(cpu_type);
>          cpu_item->vcpus_count = 1;
> +        cpu_item->vcpu_id = i;
>          cpu_props->has_socket_id = true;
>          cpu_props->socket_id = topo.pkg_id;
>          cpu_props->has_core_id = true;
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 7f33a1b..d1f5195 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2378,6 +2378,7 @@ static HotpluggableCPUList *spapr_query_hotpluggable_cpus(MachineState *machine)
> 
>          cpu_item->type = spapr_get_cpu_core_type(machine->cpu_model);
>          cpu_item->vcpus_count = smp_threads;
> +        cpu_item->vcpu_id = i;

This is wrong.  This is the index of the core.  The individual vcpus
within the core will have ids starting at core_id and working up.

>          cpu_props->has_core_id = true;
>          cpu_props->core_id = i * smt;
>          /* TODO: add 'has_node/node' here to describe
> diff --git a/qapi-schema.json b/qapi-schema.json
> index ba3bf14..6db9294 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -4292,6 +4292,7 @@
>  # @type: CPU object type for usage with device_add command
>  # @props: list of properties to be used for hotplugging CPU
>  # @vcpus-count: number of logical VCPU threads @HotpluggableCPU provides
> +# @vcpu-id: linear index of the vcpu
>  # @qom-path: #optional link to existing CPU object if CPU is present or
>  #            omitted if CPU is not present.
>  #
> @@ -4300,6 +4301,7 @@
>  { 'struct': 'HotpluggableCPU',
>    'data': { 'type': 'str',
>              'vcpus-count': 'int',
> +            'vcpu-id': 'int',
>              'props': 'CpuInstanceProperties',
>              '*qom-path': 'str'
>            }
> -- 
> 2.9.0
>
Igor Mammedov July 8, 2016, 11:40 a.m. UTC | #2
On Fri, 8 Jul 2016 12:18:55 +1000
David Gibson <dgibson@redhat.com> wrote:

> On Thu,  7 Jul 2016 17:17:13 +0200
> Peter Krempa <pkrempa@redhat.com> wrote:
> 
> > Add 'vcpu index' to the output of query hotpluggable cpus. This output
> > is identical to the linear cpu index taken by the 'cpus' attribute
> > passed to -numa.  
> 
> 
> The problem is, the vcpu index of what?  Each entry in the hotpluggable
> cpus table could represent more than one vcpu.
agreed,
-numa cpus should take socket/core/thread-ids instead so that mgmt
could do layout at start-up time

for example if mgmt specifies
  -smp cpus=1,sockets=2,cores=2,maxcpus=4
it knows socket/core layout and can assign them as desired
  -numa nodeid=0,cpu=[socket-id=0,core-id=0] \
  -numa nodeid=1,cpu=[socket-id=0,core-id=1] \
  -numa nodeid=2,cpu=[socket-id=1]

that of cause assuming that QEMU would guarantee IDs are are ranges [0..sockets), ...
it's so for x86, can we guarantee it for spapr?

> 
> > This will allow to reliably map the cpu number to a given topology
> > element without making mgmt apps to reimplement the mapping.
> > 
> > Signed-off-by: Peter Krempa <pkrempa@redhat.com>
> > ---
> >  hmp.c            | 1 +
> >  hw/i386/pc.c     | 1 +
> >  hw/ppc/spapr.c   | 1 +
> >  qapi-schema.json | 2 ++
> >  4 files changed, 5 insertions(+)
> > 
> > diff --git a/hmp.c b/hmp.c
> > index 0cf5baa..613601e 100644
> > --- a/hmp.c
> > +++ b/hmp.c
> > @@ -2450,6 +2450,7 @@ void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
> >          monitor_printf(mon, "  type: \"%s\"\n", l->value->type);
> >          monitor_printf(mon, "  vcpus_count: \"%" PRIu64 "\"\n",
> >                         l->value->vcpus_count);
> > +        monitor_printf(mon, "  vcpu_id: \"%" PRIu64 "\"\n", l->value->vcpu_id);
> >          if (l->value->has_qom_path) {
> >              monitor_printf(mon, "  qom_path: \"%s\"\n", l->value->qom_path);
> >          }
> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > index f293a0c..4ba02c4 100644
> > --- a/hw/i386/pc.c
> > +++ b/hw/i386/pc.c
> > @@ -2131,6 +2131,7 @@ static HotpluggableCPUList *pc_query_hotpluggable_cpus(MachineState *machine)
> > 
> >          cpu_item->type = g_strdup(cpu_type);
> >          cpu_item->vcpus_count = 1;
> > +        cpu_item->vcpu_id = i;
> >          cpu_props->has_socket_id = true;
> >          cpu_props->socket_id = topo.pkg_id;
> >          cpu_props->has_core_id = true;
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index 7f33a1b..d1f5195 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -2378,6 +2378,7 @@ static HotpluggableCPUList *spapr_query_hotpluggable_cpus(MachineState *machine)
> > 
> >          cpu_item->type = spapr_get_cpu_core_type(machine->cpu_model);
> >          cpu_item->vcpus_count = smp_threads;
> > +        cpu_item->vcpu_id = i;  
> 
> This is wrong.  This is the index of the core.  The individual vcpus
> within the core will have ids starting at core_id and working up.
> 
> >          cpu_props->has_core_id = true;
> >          cpu_props->core_id = i * smt;
> >          /* TODO: add 'has_node/node' here to describe
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index ba3bf14..6db9294 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -4292,6 +4292,7 @@
> >  # @type: CPU object type for usage with device_add command
> >  # @props: list of properties to be used for hotplugging CPU
> >  # @vcpus-count: number of logical VCPU threads @HotpluggableCPU provides
> > +# @vcpu-id: linear index of the vcpu
> >  # @qom-path: #optional link to existing CPU object if CPU is present or
> >  #            omitted if CPU is not present.
> >  #
> > @@ -4300,6 +4301,7 @@
> >  { 'struct': 'HotpluggableCPU',
> >    'data': { 'type': 'str',
> >              'vcpus-count': 'int',
> > +            'vcpu-id': 'int',
> >              'props': 'CpuInstanceProperties',
> >              '*qom-path': 'str'
> >            }
> > -- 
> > 2.9.0
> >   
> 
>
David Gibson July 11, 2016, 3:30 a.m. UTC | #3
On Fri, 8 Jul 2016 13:40:38 +0200
Igor Mammedov <imammedo@redhat.com> wrote:

> On Fri, 8 Jul 2016 12:18:55 +1000
> David Gibson <dgibson@redhat.com> wrote:
> 
> > On Thu,  7 Jul 2016 17:17:13 +0200
> > Peter Krempa <pkrempa@redhat.com> wrote:
> >   
> > > Add 'vcpu index' to the output of query hotpluggable cpus. This output
> > > is identical to the linear cpu index taken by the 'cpus' attribute
> > > passed to -numa.    
> > 
> > 
> > The problem is, the vcpu index of what?  Each entry in the hotpluggable
> > cpus table could represent more than one vcpu.  
> agreed,
> -numa cpus should take socket/core/thread-ids instead so that mgmt
> could do layout at start-up time
> 
> for example if mgmt specifies
>   -smp cpus=1,sockets=2,cores=2,maxcpus=4
> it knows socket/core layout and can assign them as desired
>   -numa nodeid=0,cpu=[socket-id=0,core-id=0] \
>   -numa nodeid=1,cpu=[socket-id=0,core-id=1] \
>   -numa nodeid=2,cpu=[socket-id=1]
> 
> that of cause assuming that QEMU would guarantee IDs are are ranges [0..sockets), ...
> it's so for x86, can we guarantee it for spapr?

Urgh.. we could for spapr, but I think it's bad idea to do that in
general.  For powernv (or others) we might want to use socket ids with
a physical meaning (e.g. actual values of chip select lines) and those
might not be contiguous.


> 
> >   
> > > This will allow to reliably map the cpu number to a given topology
> > > element without making mgmt apps to reimplement the mapping.
> > > 
> > > Signed-off-by: Peter Krempa <pkrempa@redhat.com>
> > > ---
> > >  hmp.c            | 1 +
> > >  hw/i386/pc.c     | 1 +
> > >  hw/ppc/spapr.c   | 1 +
> > >  qapi-schema.json | 2 ++
> > >  4 files changed, 5 insertions(+)
> > > 
> > > diff --git a/hmp.c b/hmp.c
> > > index 0cf5baa..613601e 100644
> > > --- a/hmp.c
> > > +++ b/hmp.c
> > > @@ -2450,6 +2450,7 @@ void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
> > >          monitor_printf(mon, "  type: \"%s\"\n", l->value->type);
> > >          monitor_printf(mon, "  vcpus_count: \"%" PRIu64 "\"\n",
> > >                         l->value->vcpus_count);
> > > +        monitor_printf(mon, "  vcpu_id: \"%" PRIu64 "\"\n", l->value->vcpu_id);
> > >          if (l->value->has_qom_path) {
> > >              monitor_printf(mon, "  qom_path: \"%s\"\n", l->value->qom_path);
> > >          }
> > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > > index f293a0c..4ba02c4 100644
> > > --- a/hw/i386/pc.c
> > > +++ b/hw/i386/pc.c
> > > @@ -2131,6 +2131,7 @@ static HotpluggableCPUList *pc_query_hotpluggable_cpus(MachineState *machine)
> > > 
> > >          cpu_item->type = g_strdup(cpu_type);
> > >          cpu_item->vcpus_count = 1;
> > > +        cpu_item->vcpu_id = i;
> > >          cpu_props->has_socket_id = true;
> > >          cpu_props->socket_id = topo.pkg_id;
> > >          cpu_props->has_core_id = true;
> > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > > index 7f33a1b..d1f5195 100644
> > > --- a/hw/ppc/spapr.c
> > > +++ b/hw/ppc/spapr.c
> > > @@ -2378,6 +2378,7 @@ static HotpluggableCPUList *spapr_query_hotpluggable_cpus(MachineState *machine)
> > > 
> > >          cpu_item->type = spapr_get_cpu_core_type(machine->cpu_model);
> > >          cpu_item->vcpus_count = smp_threads;
> > > +        cpu_item->vcpu_id = i;    
> > 
> > This is wrong.  This is the index of the core.  The individual vcpus
> > within the core will have ids starting at core_id and working up.
> >   
> > >          cpu_props->has_core_id = true;
> > >          cpu_props->core_id = i * smt;
> > >          /* TODO: add 'has_node/node' here to describe
> > > diff --git a/qapi-schema.json b/qapi-schema.json
> > > index ba3bf14..6db9294 100644
> > > --- a/qapi-schema.json
> > > +++ b/qapi-schema.json
> > > @@ -4292,6 +4292,7 @@
> > >  # @type: CPU object type for usage with device_add command
> > >  # @props: list of properties to be used for hotplugging CPU
> > >  # @vcpus-count: number of logical VCPU threads @HotpluggableCPU provides
> > > +# @vcpu-id: linear index of the vcpu
> > >  # @qom-path: #optional link to existing CPU object if CPU is present or
> > >  #            omitted if CPU is not present.
> > >  #
> > > @@ -4300,6 +4301,7 @@
> > >  { 'struct': 'HotpluggableCPU',
> > >    'data': { 'type': 'str',
> > >              'vcpus-count': 'int',
> > > +            'vcpu-id': 'int',
> > >              'props': 'CpuInstanceProperties',
> > >              '*qom-path': 'str'
> > >            }
> > > -- 
> > > 2.9.0
> > >     
> > 
> >   
>
Igor Mammedov July 11, 2016, 8:23 a.m. UTC | #4
On Mon, 11 Jul 2016 13:30:38 +1000
David Gibson <dgibson@redhat.com> wrote:

> On Fri, 8 Jul 2016 13:40:38 +0200
> Igor Mammedov <imammedo@redhat.com> wrote:
> 
> > On Fri, 8 Jul 2016 12:18:55 +1000
> > David Gibson <dgibson@redhat.com> wrote:
> >   
> > > On Thu,  7 Jul 2016 17:17:13 +0200
> > > Peter Krempa <pkrempa@redhat.com> wrote:
> > >     
> > > > Add 'vcpu index' to the output of query hotpluggable cpus. This output
> > > > is identical to the linear cpu index taken by the 'cpus' attribute
> > > > passed to -numa.      
> > > 
> > > 
> > > The problem is, the vcpu index of what?  Each entry in the hotpluggable
> > > cpus table could represent more than one vcpu.    
> > agreed,
> > -numa cpus should take socket/core/thread-ids instead so that mgmt
> > could do layout at start-up time
> > 
> > for example if mgmt specifies
> >   -smp cpus=1,sockets=2,cores=2,maxcpus=4
> > it knows socket/core layout and can assign them as desired
> >   -numa nodeid=0,cpu=[socket-id=0,core-id=0] \
> >   -numa nodeid=1,cpu=[socket-id=0,core-id=1] \
> >   -numa nodeid=2,cpu=[socket-id=1]
> > 
> > that of cause assuming that QEMU would guarantee IDs are are ranges [0..sockets), ...
> > it's so for x86, can we guarantee it for spapr?  
> 
> Urgh.. we could for spapr, but I think it's bad idea to do that in
> general.  For powernv (or others) we might want to use socket ids with
> a physical meaning (e.g. actual values of chip select lines) and those
> might not be contiguous.
Are there any other ideas how we can design numa mapping interface, then?

> 
> 
> >   
> > >     
> > > > This will allow to reliably map the cpu number to a given topology
> > > > element without making mgmt apps to reimplement the mapping.
> > > > 
> > > > Signed-off-by: Peter Krempa <pkrempa@redhat.com>
> > > > ---
> > > >  hmp.c            | 1 +
> > > >  hw/i386/pc.c     | 1 +
> > > >  hw/ppc/spapr.c   | 1 +
> > > >  qapi-schema.json | 2 ++
> > > >  4 files changed, 5 insertions(+)
> > > > 
> > > > diff --git a/hmp.c b/hmp.c
> > > > index 0cf5baa..613601e 100644
> > > > --- a/hmp.c
> > > > +++ b/hmp.c
> > > > @@ -2450,6 +2450,7 @@ void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
> > > >          monitor_printf(mon, "  type: \"%s\"\n", l->value->type);
> > > >          monitor_printf(mon, "  vcpus_count: \"%" PRIu64 "\"\n",
> > > >                         l->value->vcpus_count);
> > > > +        monitor_printf(mon, "  vcpu_id: \"%" PRIu64 "\"\n", l->value->vcpu_id);
> > > >          if (l->value->has_qom_path) {
> > > >              monitor_printf(mon, "  qom_path: \"%s\"\n", l->value->qom_path);
> > > >          }
> > > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > > > index f293a0c..4ba02c4 100644
> > > > --- a/hw/i386/pc.c
> > > > +++ b/hw/i386/pc.c
> > > > @@ -2131,6 +2131,7 @@ static HotpluggableCPUList *pc_query_hotpluggable_cpus(MachineState *machine)
> > > > 
> > > >          cpu_item->type = g_strdup(cpu_type);
> > > >          cpu_item->vcpus_count = 1;
> > > > +        cpu_item->vcpu_id = i;
> > > >          cpu_props->has_socket_id = true;
> > > >          cpu_props->socket_id = topo.pkg_id;
> > > >          cpu_props->has_core_id = true;
> > > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > > > index 7f33a1b..d1f5195 100644
> > > > --- a/hw/ppc/spapr.c
> > > > +++ b/hw/ppc/spapr.c
> > > > @@ -2378,6 +2378,7 @@ static HotpluggableCPUList *spapr_query_hotpluggable_cpus(MachineState *machine)
> > > > 
> > > >          cpu_item->type = spapr_get_cpu_core_type(machine->cpu_model);
> > > >          cpu_item->vcpus_count = smp_threads;
> > > > +        cpu_item->vcpu_id = i;      
> > > 
> > > This is wrong.  This is the index of the core.  The individual vcpus
> > > within the core will have ids starting at core_id and working up.
> > >     
> > > >          cpu_props->has_core_id = true;
> > > >          cpu_props->core_id = i * smt;
> > > >          /* TODO: add 'has_node/node' here to describe
> > > > diff --git a/qapi-schema.json b/qapi-schema.json
> > > > index ba3bf14..6db9294 100644
> > > > --- a/qapi-schema.json
> > > > +++ b/qapi-schema.json
> > > > @@ -4292,6 +4292,7 @@
> > > >  # @type: CPU object type for usage with device_add command
> > > >  # @props: list of properties to be used for hotplugging CPU
> > > >  # @vcpus-count: number of logical VCPU threads @HotpluggableCPU provides
> > > > +# @vcpu-id: linear index of the vcpu
> > > >  # @qom-path: #optional link to existing CPU object if CPU is present or
> > > >  #            omitted if CPU is not present.
> > > >  #
> > > > @@ -4300,6 +4301,7 @@
> > > >  { 'struct': 'HotpluggableCPU',
> > > >    'data': { 'type': 'str',
> > > >              'vcpus-count': 'int',
> > > > +            'vcpu-id': 'int',
> > > >              'props': 'CpuInstanceProperties',
> > > >              '*qom-path': 'str'
> > > >            }
> > > > -- 
> > > > 2.9.0
> > > >       
> > > 
> > >     
> >   
> 
>
diff mbox

Patch

diff --git a/hmp.c b/hmp.c
index 0cf5baa..613601e 100644
--- a/hmp.c
+++ b/hmp.c
@@ -2450,6 +2450,7 @@  void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "  type: \"%s\"\n", l->value->type);
         monitor_printf(mon, "  vcpus_count: \"%" PRIu64 "\"\n",
                        l->value->vcpus_count);
+        monitor_printf(mon, "  vcpu_id: \"%" PRIu64 "\"\n", l->value->vcpu_id);
         if (l->value->has_qom_path) {
             monitor_printf(mon, "  qom_path: \"%s\"\n", l->value->qom_path);
         }
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index f293a0c..4ba02c4 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -2131,6 +2131,7 @@  static HotpluggableCPUList *pc_query_hotpluggable_cpus(MachineState *machine)

         cpu_item->type = g_strdup(cpu_type);
         cpu_item->vcpus_count = 1;
+        cpu_item->vcpu_id = i;
         cpu_props->has_socket_id = true;
         cpu_props->socket_id = topo.pkg_id;
         cpu_props->has_core_id = true;
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 7f33a1b..d1f5195 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2378,6 +2378,7 @@  static HotpluggableCPUList *spapr_query_hotpluggable_cpus(MachineState *machine)

         cpu_item->type = spapr_get_cpu_core_type(machine->cpu_model);
         cpu_item->vcpus_count = smp_threads;
+        cpu_item->vcpu_id = i;
         cpu_props->has_core_id = true;
         cpu_props->core_id = i * smt;
         /* TODO: add 'has_node/node' here to describe
diff --git a/qapi-schema.json b/qapi-schema.json
index ba3bf14..6db9294 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4292,6 +4292,7 @@ 
 # @type: CPU object type for usage with device_add command
 # @props: list of properties to be used for hotplugging CPU
 # @vcpus-count: number of logical VCPU threads @HotpluggableCPU provides
+# @vcpu-id: linear index of the vcpu
 # @qom-path: #optional link to existing CPU object if CPU is present or
 #            omitted if CPU is not present.
 #
@@ -4300,6 +4301,7 @@ 
 { 'struct': 'HotpluggableCPU',
   'data': { 'type': 'str',
             'vcpus-count': 'int',
+            'vcpu-id': 'int',
             'props': 'CpuInstanceProperties',
             '*qom-path': 'str'
           }