Re: [Qemu-devel] [PATCH v2 1/3] hw/acpi-build: build SRAT memory affinity structures for DIMM devices

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 28 Feb 2018 12:02:58 +0800
Haozhong Zhang <haozhong.zhang@intel.com> wrote:

> ACPI 6.2A Table 5-129 "SPA Range Structure" requires the proximity
> domain of a NVDIMM SPA range must match with corresponding entry in
> SRAT table.
> 
> The address ranges of vNVDIMM in QEMU are allocated from the
> hot-pluggable address space, which is entirely covered by one SRAT
> memory affinity structure. However, users can set the vNVDIMM
> proximity domain in NFIT SPA range structure by the 'node' property of
> '-device nvdimm' to a value different than the one in the above SRAT
> memory affinity structure.
> 
> In order to solve such proximity domain mismatch, this patch builds
> one SRAT memory affinity structure for each static-plugged DIMM device,
s/static-plugged/present at boot/
since after hotplug and following reset SRAT will be recreated
and include hotplugged DIMMs as well.

> including both PC-DIMM and NVDIMM, with the proximity domain specified
> in '-device pc-dimm' or '-device nvdimm'.
> 
> The remaining hot-pluggable address space is covered by one or multiple
> SRAT memory affinity structures with the proximity domain of the last
> node as before.
> 
> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
> ---
>  hw/i386/acpi-build.c     | 50 ++++++++++++++++++++++++++++++++++++++++++++----
>  hw/mem/pc-dimm.c         |  8 ++++++++
>  include/hw/mem/pc-dimm.h | 10 ++++++++++
>  3 files changed, 64 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index deb440f286..a88de06d8f 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2323,6 +2323,49 @@ build_tpm2(GArray *table_data, BIOSLinker *linker, GArray *tcpalog)
>  #define HOLE_640K_START  (640 * 1024)
>  #define HOLE_640K_END   (1024 * 1024)
>  
> +static void build_srat_hotpluggable_memory(GArray *table_data, uint64_t base,
> +                                           uint64_t len, int default_node)
> +{
> +    GSList *dimms = pc_dimm_get_device_list();
> +    GSList *ent = dimms;
> +    PCDIMMDevice *dev;
> +    Object *obj;
> +    uint64_t end = base + len, addr, size;
> +    int node;
> +    AcpiSratMemoryAffinity *numamem;
> +
> +    while (base < end) {
It's just matter of taste but wouldn't 'for' loop be better here?
One can see start, end and next step from the begging.

> +        numamem = acpi_data_push(table_data, sizeof *numamem);
> +
> +        if (!ent) {
> +            build_srat_memory(numamem, base, end - base, default_node,
> +                              MEM_AFFINITY_HOTPLUGGABLE | MEM_AFFINITY_ENABLED);
> +            break;
> +        }
> +
> +        dev = PC_DIMM(ent->data);
> +        obj = OBJECT(dev);
> +        addr = object_property_get_uint(obj, PC_DIMM_ADDR_PROP, NULL);
> +        size = object_property_get_uint(obj, PC_DIMM_SIZE_PROP, NULL);
> +        node = object_property_get_uint(obj, PC_DIMM_NODE_PROP, NULL);
> +
> +        if (base < addr) {
> +            build_srat_memory(numamem, base, addr - base, default_node,
> +                              MEM_AFFINITY_HOTPLUGGABLE | MEM_AFFINITY_ENABLED);
> +            numamem = acpi_data_push(table_data, sizeof *numamem);
> +        }
> +        build_srat_memory(numamem, addr, size, node,
> +                          MEM_AFFINITY_HOTPLUGGABLE | MEM_AFFINITY_ENABLED |
Is NVDIMM hotplug supported in QEMU?
If not we might need make MEM_AFFINITY_HOTPLUGGABLE conditional too.

> +                          (object_dynamic_cast(obj, TYPE_NVDIMM) ?
> +                           MEM_AFFINITY_NON_VOLATILE : 0));
it might be cleaner without inline flags duplication

  flags = MEM_AFFINITY_ENABLED;
  ...
  if (!ent) {
      flags |= MEM_AFFINITY_HOTPLUGGABLE
  }
  ...
  if (PCDIMMDeviceInfo::hotpluggable) { // see ***
      flags |= MEM_AFFINITY_HOTPLUGGABLE
  }
  ...
  if (object_dynamic_cast(obj, TYPE_NVDIMM))
      flags |= MEM_AFFINITY_NON_VOLATILE
  }

> +
> +        base = addr + size;
> +        ent = g_slist_next(ent);
> +    }
> +
> +    g_slist_free(dimms);
> +}
> +
>  static void
>  build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
>  {
> @@ -2434,10 +2477,9 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
>       * providing _PXM method if necessary.
>       */
>      if (hotplugabble_address_space_size) {
> -        numamem = acpi_data_push(table_data, sizeof *numamem);
> -        build_srat_memory(numamem, pcms->hotplug_memory.base,
> -                          hotplugabble_address_space_size, pcms->numa_nodes - 1,
> -                          MEM_AFFINITY_HOTPLUGGABLE | MEM_AFFINITY_ENABLED);
> +        build_srat_hotpluggable_memory(table_data, pcms->hotplug_memory.base,
> +                                       hotplugabble_address_space_size,
> +                                       pcms->numa_nodes - 1);
>      }
>  
>      build_header(linker, table_data,
> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> index 6e74b61cb6..9fd901e87a 100644
> --- a/hw/mem/pc-dimm.c
> +++ b/hw/mem/pc-dimm.c
> @@ -276,6 +276,14 @@ static int pc_dimm_built_list(Object *obj, void *opaque)
>      return 0;
>  }
>  
> +GSList *pc_dimm_get_device_list(void)
> +{
> +    GSList *list = NULL;
> +
> +    object_child_foreach(qdev_get_machine(), pc_dimm_built_list, &list);
> +    return list;
> +}
(***)
see http://lists.gnu.org/archive/html/qemu-ppc/2018-02/msg00271.html
You could do that in separate patch, so that it won't matter
whose patch got merged first and it won't affect the rest of patches.


>  uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
>                                 uint64_t address_space_size,
>                                 uint64_t *hint, uint64_t align, uint64_t size,
> diff --git a/include/hw/mem/pc-dimm.h b/include/hw/mem/pc-dimm.h
> index d83b957829..4cf5cc49e9 100644
> --- a/include/hw/mem/pc-dimm.h
> +++ b/include/hw/mem/pc-dimm.h
> @@ -100,4 +100,14 @@ void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
>                           MemoryRegion *mr, uint64_t align, Error **errp);
>  void pc_dimm_memory_unplug(DeviceState *dev, MemoryHotplugState *hpms,
>                             MemoryRegion *mr);
> +
> +/*
> + * Return a list of DeviceState of pc-dimm and nvdimm devices. The
> + * list is sorted in the ascendant order of the base address of
> + * devices.
> + *
> + * Note: callers are responsible to free the list.
> + */
> +GSList *pc_dimm_get_device_list(void);
> +
>  #endif