Re: [PATCH v4] numa: forbid '-numa node,mem' for 5.1 and newer machine types

On Mon, Jun 08, 2020 at 08:03:44AM -0400, Igor Mammedov wrote: > Deprecation period is run out and it's a time to flip the switch > introduced by cd5ff8333a. Disable legacy option for new machine > types (since 5.1) and amend documentation. > > '-numa node,memdev' shall be used instead of disabled option > with new machine types. > > Signed-off-by: Igor Mammedov <imammedo(a)redhat.com&gt; > Reviewed-by: Michal Privoznik <mprivozn(a)redhat.com&gt; Reviewed-by: Michael S. Tsirkin <mst(a)redhat.com&gt;

numa things so I'm guessing Eduardo's tree?

> --- > v1: > - rebased on top of current master > - move compat mode from 4.2 to 5.0 > v2: > - move deprection text to recently removed section > v3: > - increase title line length for (deprecated.rst) > '``-numa node,mem=``\ *size* (removed in 5.1)' > v4: > - use error_append_hint() for suggesting valid CLI > > CC: peter.maydell(a)linaro.org > CC: ehabkost(a)redhat.com > CC: marcel.apfelbaum(a)gmail.com > CC: mst(a)redhat.com > CC: pbonzini(a)redhat.com > CC: rth(a)twiddle.net > CC: david(a)gibson.dropbear.id.au > CC: libvir-list(a)redhat.com > CC: qemu-arm(a)nongnu.org > CC: qemu-ppc(a)nongnu.org > CC: eblake(a)redhat.com > CC: groug(a)kaod.org > --- > docs/system/deprecated.rst | 37 ++++++++++++++++++++----------------- > hw/arm/virt.c | 2 +- > hw/core/numa.c | 7 +++++++ > hw/i386/pc.c | 1 - > hw/i386/pc_piix.c | 1 + > hw/i386/pc_q35.c | 1 + > hw/ppc/spapr.c | 2 +- > qemu-options.hx | 9 +++++---- > 8 files changed, 36 insertions(+), 24 deletions(-) > > diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst > index 544ece0a45..e74a5717c8 100644 > --- a/docs/system/deprecated.rst > +++ b/docs/system/deprecated.rst > @@ -101,23 +101,6 @@ error in the future. > The ``-realtime mlock=on|off`` argument has been replaced by the > ``-overcommit mem-lock=on|off`` argument. > > -``-numa node,mem=``\ *size* (since 4.1) > -''''''''''''''''''''''''''''''''''''''' > - > -The parameter ``mem`` of ``-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 ``memdev``, which does the same as ``mem`` and adds > -means to actualy manage node RAM on the host side. Use parameter ``memdev`` > -with *memory-backend-ram* backend as an replacement for parameter ``mem`` > -to achieve the same fake NUMA effect or a properly configured > -*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. > - > ``-numa`` node (without memory specified) (since 4.1) > ''''''''''''''''''''''''''''''''''''''''''''''''''''' > > @@ -516,3 +499,23 @@ long starting at 1MiB, the old command:: > can be rewritten as:: > > qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.file.driver=file,file.file.filename=file.qcow2 > + > +Command line options > +-------------------- > + > +``-numa node,mem=``\ *size* (removed in 5.1) > +'''''''''''''''''''''''''''''''''''''''''''' > + > +The parameter ``mem`` of ``-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 ``memdev``, which does the same as ``mem`` and adds > +means to actualy manage node RAM on the host side. Use parameter ``memdev`` > +with *memory-backend-ram* backend as an replacement for parameter ``mem`` > +to achieve the same fake NUMA effect or a properly configured > +*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. > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > index 37462a6f78..063d4703f7 100644 > --- a/hw/arm/virt.c > +++ b/hw/arm/virt.c > @@ -2262,7 +2262,6 @@ 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->nvdimm_supported = true; > mc->auto_enable_numa_with_memhp = true; > mc->default_ram_id = "mach-virt.ram"; > @@ -2375,6 +2374,7 @@ DEFINE_VIRT_MACHINE_AS_LATEST(5, 1) > static void virt_machine_5_0_options(MachineClass *mc) > { > virt_machine_5_1_options(mc); > + mc->numa_mem_supported = true; > } > DEFINE_VIRT_MACHINE(5, 0) > > diff --git a/hw/core/numa.c b/hw/core/numa.c > index 316bc50d75..7814e646e4 100644 > --- a/hw/core/numa.c > +++ b/hw/core/numa.c > @@ -117,6 +117,13 @@ 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"); > + error_append_hint(errp, "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 2128f3d6fe..a86136069c 100644 > --- a/hw/i386/pc.c > +++ b/hw/i386/pc.c > @@ -1960,7 +1960,6 @@ 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 f66e1d73ce..8955436efa 100644 > --- a/hw/i386/pc_piix.c > +++ b/hw/i386/pc_piix.c > @@ -438,6 +438,7 @@ static void pc_i440fx_5_0_machine_options(MachineClass *m) > pc_i440fx_5_1_machine_options(m); > m->alias = NULL; > m->is_default = false; > + m->numa_mem_supported = true; > compat_props_add(m->compat_props, hw_compat_5_0, hw_compat_5_0_len); > compat_props_add(m->compat_props, pc_compat_5_0, pc_compat_5_0_len); > } > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c > index 4ba8ac8774..af6b32adb7 100644 > --- a/hw/i386/pc_q35.c > +++ b/hw/i386/pc_q35.c > @@ -366,6 +366,7 @@ static void pc_q35_5_0_machine_options(MachineClass *m) > { > pc_q35_5_1_machine_options(m); > m->alias = NULL; > + m->numa_mem_supported = true; > compat_props_add(m->compat_props, hw_compat_5_0, hw_compat_5_0_len); > compat_props_add(m->compat_props, pc_compat_5_0, pc_compat_5_0_len); > } > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 3b1a5ed865..210d61d1b3 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -4511,7 +4511,6 @@ 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; > @@ -4599,6 +4598,7 @@ static void spapr_machine_5_0_class_options(MachineClass *mc) > { > spapr_machine_5_1_class_options(mc); > compat_props_add(mc->compat_props, hw_compat_5_0, hw_compat_5_0_len); > + mc->numa_mem_supported = true; > } > > DEFINE_SPAPR_MACHINE(5_0, "5.0", false); > diff --git a/qemu-options.hx b/qemu-options.hx > index 93bde2bbc8..196f468786 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -239,10 +239,11 @@ SRST > -numa node,nodeid=0 -numa node,nodeid=1 \ > -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 > > - '\ ``mem``\ ' assigns a given RAM amount to a node. '\ ``memdev``\ ' > - assigns RAM from a given memory backend device to a node. If > - '\ ``mem``\ ' and '\ ``memdev``\ ' are omitted in all nodes, RAM is > - split equally between them. > + Legacy '\ ``mem``\ ' assigns a given RAM amount to a node (not supported > + for 5.1 and newer machine types). '\ ``memdev``\ ' assigns RAM from > + a given memory backend device to a node. If '\ ``mem``\ ' and > + '\ ``memdev``\ ' are omitted in all nodes, RAM is split equally between them. > + > > '\ ``mem``\ ' and '\ ``memdev``\ ' are mutually exclusive. > Furthermore, if one node uses '\ ``memdev``\ ', all of them have to > -- > 2.26.2