numa: Auto-enable NUMA when any memory devices are possible

Let's auto-enable it also when maxmem is specified but no slots are
defined. This will result in us properly creating ACPI srat tables,
indicating the maximum possible PFN to the guest OS. Based on this, e.g.,
Linux will enable the swiotlb properly.

This avoids having to manually force the switolb on (swiotlb=force) in
Linux in case we're booting only using DMA memory (e.g., 2GB on x86-64),
and virtio-mem adds memory later on that really needs the swiotlb to be
used for DMA.

Let's take care of backwards compatibility if somebody has a setup that
specifies "maxram" without "slots".

Reported-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Sergio Lopez <slp@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: qemu-arm@nongnu.org <qemu-arm@nongnu.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200626072248.78761-22-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index cd0834ce7fafdfa4458bc1442503df417a5a91e5..f97be80a86523cfb93d67a611f59532083b45fe0 100644 (file)
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2373,6 +2373,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
     hc->unplug = virt_machine_device_unplug_cb;
     mc->nvdimm_supported = true;
     mc->auto_enable_numa_with_memhp = true;
+    mc->auto_enable_numa_with_memdev = true;
     mc->default_ram_id = "mach-virt.ram";
 
     object_class_property_add(oc, "acpi", "OnOffAuto",
@@ -2485,6 +2486,7 @@ static void virt_machine_5_0_options(MachineClass *mc)
     virt_machine_5_1_options(mc);
     compat_props_add(mc->compat_props, hw_compat_5_0, hw_compat_5_0_len);
     mc->numa_mem_supported = true;
+    mc->auto_enable_numa_with_memdev = false;
 }
 DEFINE_VIRT_MACHINE(5, 0)
 

diff --git a/hw/core/numa.c b/hw/core/numa.c
index e9aec69afde8b0b57c8f9a050973b2fa668107b8..6a20ce7cf18ef7660245c7eb98871d1b59a84bdf 100644 (file)
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -688,8 +688,9 @@ void numa_complete_configuration(MachineState *ms)
     NodeInfo *numa_info = ms->numa_state->nodes;
 
     /*
-     * If memory hotplug is enabled (slots > 0) but without '-numa'
-     * options explicitly on CLI, guestes will break.
+     * If memory hotplug is enabled (slot > 0) or memory devices are enabled
+     * (ms->maxram_size > ram_size) but without '-numa' options explicitly on
+     * CLI, guests will break.
      *
      *   Windows: won't enable memory hotplug without SRAT table at all
      *
@@ -704,9 +705,9 @@ void numa_complete_configuration(MachineState *ms)
      * assume there is just one node with whole RAM.
      */
     if (ms->numa_state->num_nodes == 0 &&
-        ((ms->ram_slots > 0 &&
-        mc->auto_enable_numa_with_memhp) ||
-        mc->auto_enable_numa)) {
+        ((ms->ram_slots && mc->auto_enable_numa_with_memhp) ||
+         (ms->maxram_size > ms->ram_size && mc->auto_enable_numa_with_memdev) ||
+         mc->auto_enable_numa)) {
             NumaNodeOptions node = { };
             parse_numa_node(ms, &node, &error_abort);
             numa_info[0].node_mem = ram_size;

diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 5e931975a06d5b25c9d573233f44df475b4a6300..81d0888930d10cb35e03792f9ca325a3c972c4c3 100644 (file)
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -464,6 +464,7 @@ static void microvm_class_init(ObjectClass *oc, void *data)
     mc->max_cpus = 288;
     mc->has_hotpluggable_cpus = false;
     mc->auto_enable_numa_with_memhp = false;
+    mc->auto_enable_numa_with_memdev = false;
     mc->default_cpu_type = TARGET_DEFAULT_CPU_TYPE;
     mc->nvdimm_supported = false;
     mc->default_ram_id = "microvm.ram";

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 576f2502f9ce5b9778e073e9e5844309b0e862df..61acc9e530c87eaa507d4d19af6a98a9aaf7720c 100644 (file)
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1975,6 +1975,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     mc->get_default_cpu_node_id = x86_get_default_cpu_node_id;
     mc->possible_cpu_arch_ids = x86_possible_cpu_arch_ids;
     mc->auto_enable_numa_with_memhp = true;
+    mc->auto_enable_numa_with_memdev = true;
     mc->has_hotpluggable_cpus = true;
     mc->default_boot_order = "cad";
     mc->hot_add_cpu = pc_hot_add_cpu;

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 1d832b2878b180dbc6ee1fd917c529c2e9ecc712..fae487f57d3ab43255210cfb909044ac9576edab 100644 (file)
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -444,6 +444,7 @@ static void pc_i440fx_5_0_machine_options(MachineClass *m)
     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);
+    m->auto_enable_numa_with_memdev = false;
 }
 
 DEFINE_I440FX_MACHINE(v5_0, "pc-i440fx-5.0", NULL,

diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 047ea8db28ea253bacd7efaf7601cba42dfd2f03..acd6d405f0bb9f468a466f0026e97a47f6c086d2 100644 (file)
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -372,6 +372,7 @@ static void pc_q35_5_0_machine_options(MachineClass *m)
     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);
+    m->auto_enable_numa_with_memhp = false;
 }
 
 DEFINE_Q35_MACHINE(v5_0, "pc-q35-5.0", NULL,

diff --git a/include/hw/boards.h b/include/hw/boards.h
index 18815d9be24f1e81149744a03d29582950a942a3..426ce5f625a4044d03f42601cf2db2261756ab21 100644 (file)
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -207,6 +207,7 @@ struct MachineClass {
     const char **valid_cpu_types;
     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;