Re: [PATCH v2 82/86] numa: forbid '-numa node, mem' for 5.0 and newer machine types

[David Gibson <david@gibson.dropbear.id.au>]

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On Wed, Jan 15, 2020 at 04:07:37PM +0100, Igor Mammedov wrote:
> Deprecation period is ran out and it's a time to flip the switch
> introduced by cd5ff8333a.
> Disable legacy option for new machine types and amend documentation.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>

ppc parts
Acked-by: David Gibson <david@gibson.dropbear.id.au>

> ---
> CC: peter.maydell@linaro.org
> CC: ehabkost@redhat.com
> CC: marcel.apfelbaum@gmail.com
> CC: mst@redhat.com
> CC: pbonzini@redhat.com
> CC: rth@twiddle.net
> CC: david@gibson.dropbear.id.au
> CC: libvir-list@redhat.com
> CC: qemu-arm@nongnu.org
> CC: qemu-ppc@nongnu.org
> ---
>  hw/arm/virt.c        |  2 +-
>  hw/core/numa.c       |  6 ++++++
>  hw/i386/pc.c         |  1 -
>  hw/i386/pc_piix.c    |  1 +
>  hw/i386/pc_q35.c     |  1 +
>  hw/ppc/spapr.c       |  2 +-
>  qemu-deprecated.texi | 16 ----------------
>  qemu-options.hx      |  8 ++++----
>  8 files changed, 14 insertions(+), 23 deletions(-)
> 
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index e2fbca3..49de0d8 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -2049,7 +2049,6 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
>      hc->pre_plug = virt_machine_device_pre_plug_cb;
>      hc->plug = virt_machine_device_plug_cb;
>      hc->unplug_request = virt_machine_device_unplug_request_cb;
> -    mc->numa_mem_supported = true;
>      mc->auto_enable_numa_with_memhp = true;
>      mc->default_ram_id = "mach-virt.ram";
>  }
> @@ -2153,6 +2152,7 @@ DEFINE_VIRT_MACHINE_AS_LATEST(5, 0)
>  static void virt_machine_4_2_options(MachineClass *mc)
>  {
>      compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len);
> +    mc->numa_mem_supported = true;
>  }
>  DEFINE_VIRT_MACHINE(4, 2)
>  
> diff --git a/hw/core/numa.c b/hw/core/numa.c
> index 0970a30..3177066 100644
> --- a/hw/core/numa.c
> +++ b/hw/core/numa.c
> @@ -117,6 +117,12 @@ static void parse_numa_node(MachineState *ms, NumaNodeOptions *node,
>      }
>  
>      if (node->has_mem) {
> +        if (!mc->numa_mem_supported) {
> +            error_setg(errp, "Parameter -numa node,mem is not supported by this"
> +                      " machine type. Use -numa node,memdev instead");
> +            return;
> +        }
> +
>          numa_info[nodenr].node_mem = node->mem;
>          if (!qtest_enabled()) {
>              warn_report("Parameter -numa node,mem is deprecated,"
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 21b8290..fa8d024 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1947,7 +1947,6 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
>      hc->unplug = pc_machine_device_unplug_cb;
>      mc->default_cpu_type = TARGET_DEFAULT_CPU_TYPE;
>      mc->nvdimm_supported = true;
> -    mc->numa_mem_supported = true;
>      mc->default_ram_id = "pc.ram";
>  
>      object_class_property_add(oc, PC_MACHINE_DEVMEM_REGION_SIZE, "int",
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index fa12203..0a9b9e0 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -435,6 +435,7 @@ static void pc_i440fx_4_2_machine_options(MachineClass *m)
>      pc_i440fx_5_0_machine_options(m);
>      m->alias = NULL;
>      m->is_default = 0;
> +    m->numa_mem_supported = true;
>      compat_props_add(m->compat_props, hw_compat_4_2, hw_compat_4_2_len);
>      compat_props_add(m->compat_props, pc_compat_4_2, pc_compat_4_2_len);
>  }
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 84cf925..4d6e2be 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -363,6 +363,7 @@ static void pc_q35_4_2_machine_options(MachineClass *m)
>  {
>      pc_q35_5_0_machine_options(m);
>      m->alias = NULL;
> +    m->numa_mem_supported = true;
>      compat_props_add(m->compat_props, hw_compat_4_2, hw_compat_4_2_len);
>      compat_props_add(m->compat_props, pc_compat_4_2, pc_compat_4_2_len);
>  }
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index bcbe1f1..2686b73 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -4383,7 +4383,6 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
>       * in which LMBs are represented and hot-added
>       */
>      mc->numa_mem_align_shift = 28;
> -    mc->numa_mem_supported = true;
>      mc->auto_enable_numa = true;
>  
>      smc->default_caps.caps[SPAPR_CAP_HTM] = SPAPR_CAP_OFF;
> @@ -4465,6 +4464,7 @@ static void spapr_machine_4_2_class_options(MachineClass *mc)
>  {
>      spapr_machine_5_0_class_options(mc);
>      compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len);
> +    mc->numa_mem_supported = true;
>  }
>  
>  DEFINE_SPAPR_MACHINE(4_2, "4.2", false);
> diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
> index 982af95..17a0e1d 100644
> --- a/qemu-deprecated.texi
> +++ b/qemu-deprecated.texi
> @@ -89,22 +89,6 @@ error in the future.
>  The @code{-realtime mlock=on|off} argument has been replaced by the
>  @code{-overcommit mem-lock=on|off} argument.
>  
> -@subsection -numa node,mem=@var{size} (since 4.1)
> -
> -The parameter @option{mem} of @option{-numa node} is used to assign a part of
> -guest RAM to a NUMA node. But when using it, it's impossible to manage specified
> -RAM chunk on the host side (like bind it to a host node, setting bind policy, ...),
> -so guest end-ups with the fake NUMA configuration with suboptiomal performance.
> -However since 2014 there is an alternative way to assign RAM to a NUMA node
> -using parameter @option{memdev}, which does the same as @option{mem} and adds
> -means to actualy manage node RAM on the host side. Use parameter @option{memdev}
> -with @var{memory-backend-ram} backend as an replacement for parameter @option{mem}
> -to achieve the same fake NUMA effect or a properly configured
> -@var{memory-backend-file} backend to actually benefit from NUMA configuration.
> -In future new machine versions will not accept the option but it will still
> -work with old machine types. User can check QAPI schema to see if the legacy
> -option is supported by looking at MachineInfo::numa-mem-supported property.
> -
>  @subsection -numa node (without memory specified) (since 4.1)
>  
>  Splitting RAM by default between NUMA nodes has the same issues as @option{mem}
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 709162c..55500bd 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -223,10 +223,10 @@ For example:
>  -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1
>  @end example
>  
> -@samp{mem} assigns a given RAM amount to a node. @samp{memdev}
> -assigns RAM from a given memory backend device to a node. If
> -@samp{mem} and @samp{memdev} are omitted in all nodes, RAM is
> -split equally between them.
> +Legacy @samp{mem} assigns a given RAM amount to a node (not supported for 5.0
> +and newer machine types). @samp{memdev} assigns RAM from a given memory backend
> +device to a node. If @samp{mem} and @samp{memdev} are omitted in all nodes, RAM
> +is split equally between them.
>  
>  @samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
>  if one node uses @samp{memdev}, all of them have to use it.

-- 
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

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