[PATCH 0/3] numa: cleanups for 5.2

[PATCH 0/3] numa: cleanups for 5.2

[Igor Mammedov]

Remove deprecated default RAM splitting beween numa
nodes that was deprecated since 4.1, and a couple of
minor numa clean ups.

Igor Mammedov (3):
  numa: drop support for '-numa node' (without memory specified)
  doc: Cleanup "'-mem-path' fallback to RAM" deprecation text
  numa: remove fixup numa_state->num_nodes to MAX_NODES

 include/hw/boards.h        |  2 --
 include/sysemu/numa.h      |  4 ---
 docs/system/deprecated.rst | 44 +++++++++++++++-------------
 hw/core/machine.c          |  1 -
 hw/core/numa.c             | 59 --------------------------------------
 hw/i386/pc_piix.c          |  1 -
 hw/i386/pc_q35.c           |  1 -
 hw/ppc/spapr.c             |  1 -
 8 files changed, 24 insertions(+), 89 deletions(-)

-- 
2.27.0

[PATCH 1/3] numa: drop support for '-numa node' (without memory specified)

[Igor Mammedov]

it was deprecated since 4.1
commit 4bb4a2732e (numa: deprecate implict memory distribution between nodes)

Users of existing VMs, wishing to preserve the same RAM distribution,
should configure it explicitly using ``-numa node,memdev`` options.
Current RAM distribution can be retrieved using HMP command
`info numa` and if separate memory devices (pc|nv-dimm) are present
use `info memory-device` and subtract device memory from output of
`info numa`.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---

 include/hw/boards.h        |  2 --
 include/sysemu/numa.h      |  4 ---
 docs/system/deprecated.rst | 23 +++++++++-------
 hw/core/machine.c          |  1 -
 hw/core/numa.c             | 55 --------------------------------------
 hw/i386/pc_piix.c          |  1 -
 hw/i386/pc_q35.c           |  1 -
 hw/ppc/spapr.c             |  1 -
 8 files changed, 14 insertions(+), 74 deletions(-)

diff --git a/include/hw/boards.h b/include/hw/boards.h
index bc5b82ad20..15fc1a2bac 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -208,8 +208,6 @@ struct MachineClass {
     strList *allowed_dynamic_sysbus_devices;
     bool auto_enable_numa_with_memhp;
     bool auto_enable_numa_with_memdev;
-    void (*numa_auto_assign_ram)(MachineClass *mc, NodeInfo *nodes,
-                                 int nb_nodes, ram_addr_t size);
     bool ignore_boot_device_suffixes;
     bool smbus_no_migration_support;
     bool nvdimm_supported;
diff --git a/include/sysemu/numa.h b/include/sysemu/numa.h
index ad58ee88f7..4173ef2afa 100644
--- a/include/sysemu/numa.h
+++ b/include/sysemu/numa.h
@@ -106,10 +106,6 @@ void parse_numa_hmat_cache(MachineState *ms, NumaHmatCacheOptions *node,
 void numa_complete_configuration(MachineState *ms);
 void query_numa_node_mem(NumaNodeMem node_mem[], MachineState *ms);
 extern QemuOptsList qemu_numa_opts;
-void numa_legacy_auto_assign_ram(MachineClass *mc, NodeInfo *nodes,
-                                 int nb_nodes, ram_addr_t size);
-void numa_default_auto_assign_ram(MachineClass *mc, NodeInfo *nodes,
-                                  int nb_nodes, ram_addr_t size);
 void numa_cpu_pre_plug(const struct CPUArchId *slot, DeviceState *dev,
                        Error **errp);
 bool numa_uses_legacy_mem(void);
diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
index 851dbdeb8a..6f9441005a 100644
--- a/docs/system/deprecated.rst
+++ b/docs/system/deprecated.rst
@@ -104,15 +104,6 @@ error in the future.
 The ``-realtime mlock=on|off`` argument has been replaced by the
 ``-overcommit mem-lock=on|off`` argument.
 
-``-numa`` node (without memory specified) (since 4.1)
-'''''''''''''''''''''''''''''''''''''''''''''''''''''
-
-Splitting RAM by default between NUMA nodes has the same issues as ``mem``
-parameter described above with the difference that the role of the user plays
-QEMU using implicit generic or board specific splitting rule.
-Use ``memdev`` with *memory-backend-ram* backend or ``mem`` (if
-it's supported by used machine type) to define mapping explictly instead.
-
 ``-mem-path`` fallback to RAM (since 4.1)
 '''''''''''''''''''''''''''''''''''''''''
 
@@ -602,6 +593,20 @@ error when ``-u`` is not used.
 Command line options
 --------------------
 
+``-numa`` node (without memory specified) (removed 5.2)
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+Splitting RAM by default between NUMA nodes had the same issues as ``mem``
+parameter with the difference that the role of the user plays QEMU using
+implicit generic or board specific splitting rule.
+Use ``memdev`` with *memory-backend-ram* backend or ``mem`` (if
+it's supported by used machine type) to define mapping explictly instead.
+Users of existing VMs, wishing to preserve the same RAM distribution, should
+configure it explicitly using ``-numa node,memdev`` options. Current RAM
+distribution can be retrieved using HMP command ``info numa`` and if separate
+memory devices (pc|nv-dimm) are present use ``info memory-device`` and subtract
+device memory from output of ``info numa``.
+
 ``-numa node,mem=``\ *size* (removed in 5.1)
 ''''''''''''''''''''''''''''''''''''''''''''
 
diff --git a/hw/core/machine.c b/hw/core/machine.c
index ea26d61237..f70d388e86 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -797,7 +797,6 @@ static void machine_class_init(ObjectClass *oc, void *data)
      * On Linux, each node's border has to be 8MB aligned
      */
     mc->numa_mem_align_shift = 23;
-    mc->numa_auto_assign_ram = numa_default_auto_assign_ram;
 
     object_class_property_add_str(oc, "kernel",
         machine_get_kernel, machine_set_kernel);
diff --git a/hw/core/numa.c b/hw/core/numa.c
index f9593ec716..706c1e84c6 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -611,42 +611,6 @@ static void complete_init_numa_distance(MachineState *ms)
     }
 }
 
-void numa_legacy_auto_assign_ram(MachineClass *mc, NodeInfo *nodes,
-                                 int nb_nodes, ram_addr_t size)
-{
-    int i;
-    uint64_t usedmem = 0;
-
-    /* Align each node according to the alignment
-     * requirements of the machine class
-     */
-
-    for (i = 0; i < nb_nodes - 1; i++) {
-        nodes[i].node_mem = (size / nb_nodes) &
-                            ~((1 << mc->numa_mem_align_shift) - 1);
-        usedmem += nodes[i].node_mem;
-    }
-    nodes[i].node_mem = size - usedmem;
-}
-
-void numa_default_auto_assign_ram(MachineClass *mc, NodeInfo *nodes,
-                                  int nb_nodes, ram_addr_t size)
-{
-    int i;
-    uint64_t usedmem = 0, node_mem;
-    uint64_t granularity = size / nb_nodes;
-    uint64_t propagate = 0;
-
-    for (i = 0; i < nb_nodes - 1; i++) {
-        node_mem = (granularity + propagate) &
-                   ~((1 << mc->numa_mem_align_shift) - 1);
-        propagate = granularity + propagate - node_mem;
-        nodes[i].node_mem = node_mem;
-        usedmem += node_mem;
-    }
-    nodes[i].node_mem = size - usedmem;
-}
-
 static void numa_init_memdev_container(MachineState *ms, MemoryRegion *ram)
 {
     int i;
@@ -717,25 +681,6 @@ void numa_complete_configuration(MachineState *ms)
             ms->numa_state->num_nodes = MAX_NODES;
         }
 
-        /* If no memory size is given for any node, assume the default case
-         * and distribute the available memory equally across all nodes
-         */
-        for (i = 0; i < ms->numa_state->num_nodes; i++) {
-            if (numa_info[i].node_mem != 0) {
-                break;
-            }
-        }
-        if (i == ms->numa_state->num_nodes) {
-            assert(mc->numa_auto_assign_ram);
-            mc->numa_auto_assign_ram(mc, numa_info,
-                                     ms->numa_state->num_nodes, ram_size);
-            if (!qtest_enabled()) {
-                warn_report("Default splitting of RAM between nodes is deprecated,"
-                            " Use '-numa node,memdev' to explictly define RAM"
-                            " allocation per node");
-            }
-        }
-
         numa_total = 0;
         for (i = 0; i < ms->numa_state->num_nodes; i++) {
             numa_total += numa_info[i].node_mem;
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 32b1453e6a..5507812c13 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -565,7 +565,6 @@ static void pc_i440fx_2_9_machine_options(MachineClass *m)
     pc_i440fx_2_10_machine_options(m);
     compat_props_add(m->compat_props, hw_compat_2_9, hw_compat_2_9_len);
     compat_props_add(m->compat_props, pc_compat_2_9, pc_compat_2_9_len);
-    m->numa_auto_assign_ram = numa_legacy_auto_assign_ram;
 }
 
 DEFINE_I440FX_MACHINE(v2_9, "pc-i440fx-2.9", NULL,
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 0cb9c18cd4..4a37bc3e6d 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -494,7 +494,6 @@ static void pc_q35_2_10_machine_options(MachineClass *m)
     pc_q35_2_11_machine_options(m);
     compat_props_add(m->compat_props, hw_compat_2_10, hw_compat_2_10_len);
     compat_props_add(m->compat_props, pc_compat_2_10, pc_compat_2_10_len);
-    m->numa_auto_assign_ram = numa_legacy_auto_assign_ram;
     m->auto_enable_numa_with_memhp = false;
 }
 
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 9bce1892b5..12fd92373d 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -4737,7 +4737,6 @@ static void spapr_machine_2_9_class_options(MachineClass *mc)
     spapr_machine_2_10_class_options(mc);
     compat_props_add(mc->compat_props, hw_compat_2_9, hw_compat_2_9_len);
     compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
-    mc->numa_auto_assign_ram = numa_legacy_auto_assign_ram;
     smc->pre_2_10_has_unused_icps = true;
     smc->resize_hpt_default = SPAPR_RESIZE_HPT_DISABLED;
 }
-- 
2.27.0

[PATCH 2/3] doc: Cleanup "'-mem-path' fallback to RAM" deprecation text

[Igor Mammedov]

it was actually removed in 5.0,
commit 68a86dc15c (numa: remove deprecated -mem-path fallback to anonymous RAM)
clean up forgotten remnants in docs.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 docs/system/deprecated.rst | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst
index 6f9441005a..f252c92901 100644
--- a/docs/system/deprecated.rst
+++ b/docs/system/deprecated.rst
@@ -104,17 +104,6 @@ error in the future.
 The ``-realtime mlock=on|off`` argument has been replaced by the
 ``-overcommit mem-lock=on|off`` argument.
 
-``-mem-path`` fallback to RAM (since 4.1)
-'''''''''''''''''''''''''''''''''''''''''
-
-Currently if guest RAM allocation from file pointed by ``mem-path``
-fails, QEMU falls back to allocating from RAM, which might result
-in unpredictable behavior since the backing file specified by the user
-is ignored. In the future, users will be responsible for making sure
-the backing storage specified with ``-mem-path`` can actually provide
-the guest RAM configured with ``-m`` and QEMU will fail to start up if
-RAM allocation is unsuccessful.
-
 RISC-V ``-bios`` (since 5.1)
 ''''''''''''''''''''''''''''
 
@@ -624,6 +613,16 @@ New machine versions (since 5.1) will not accept the option but it will still
 work with old machine types. User can check the QAPI schema to see if the legacy
 option is supported by looking at MachineInfo::numa-mem-supported property.
 
+``-mem-path`` fallback to RAM (remove 5.0)
+''''''''''''''''''''''''''''''''''''''''''
+
+If guest RAM allocation from file pointed by ``mem-path`` failed,
+QEMU was falling back to allocating from RAM, which might have resulted
+in unpredictable behavior since the backing file specified by the user
+as ignored. Currently, users are responsible for making sure the backing storage
+specified with ``-mem-path`` can actually provide the guest RAM configured with
+``-m`` and QEMU fails to start up if RAM allocation is unsuccessful.
+
 Block devices
 -------------
 
-- 
2.27.0

[PATCH 3/3] numa: remove fixup numa_state->num_nodes to MAX_NODES

[Igor Mammedov]

current code permits only nodeids in [0..MAX_NODES) range
due to nodeid check in

  parse_numa_node()
      if (nodenr >= MAX_NODES) {
          error_setg(errp, "Max number of NUMA nodes reached: %"

so subj fixup is not reachable, drop it.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 hw/core/numa.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/hw/core/numa.c b/hw/core/numa.c
index 706c1e84c6..7d5d413001 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -677,10 +677,6 @@ void numa_complete_configuration(MachineState *ms)
     if (ms->numa_state->num_nodes > 0) {
         uint64_t numa_total;
 
-        if (ms->numa_state->num_nodes > MAX_NODES) {
-            ms->numa_state->num_nodes = MAX_NODES;
-        }
-
         numa_total = 0;
         for (i = 0; i < ms->numa_state->num_nodes; i++) {
             numa_total += numa_info[i].node_mem;
-- 
2.27.0

Re: [PATCH 0/3] numa: cleanups for 5.2

[Paolo Bonzini]

On 11/09/20 10:44, Igor Mammedov wrote:
> Remove deprecated default RAM splitting beween numa
> nodes that was deprecated since 4.1, and a couple of
> minor numa clean ups.
> 
> Igor Mammedov (3):
>   numa: drop support for '-numa node' (without memory specified)
>   doc: Cleanup "'-mem-path' fallback to RAM" deprecation text
>   numa: remove fixup numa_state->num_nodes to MAX_NODES
> 
>  include/hw/boards.h        |  2 --
>  include/sysemu/numa.h      |  4 ---
>  docs/system/deprecated.rst | 44 +++++++++++++++-------------
>  hw/core/machine.c          |  1 -
>  hw/core/numa.c             | 59 --------------------------------------
>  hw/i386/pc_piix.c          |  1 -
>  hw/i386/pc_q35.c           |  1 -
>  hw/ppc/spapr.c             |  1 -
>  8 files changed, 24 insertions(+), 89 deletions(-)
> 

Queued, thanks.

Paolo