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

[Igor Mammedov <imammedo@redhat.com>]

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>
---
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.
-- 
2.7.4