Re: [PATCH v2 2/3] hw/acpi-build: account for NVDIMM numa nodes in SRAT

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 27 May 2020 23:48:06 -0600
Vishal Verma <vishal.l.verma@intel.com> wrote:

> NVDIMMs can belong to their own proximity domains, as described by the
> NFIT. In such cases, the SRAT needs to have Memory Affinity structures
> in the SRAT for these NVDIMMs, otherwise Linux doesn't populate node
> data structures properly during NUMA initialization. See the following
> for an example failure case.
> 
> https://lore.kernel.org/linux-nvdimm/20200416225438.15208-1-vishal.l.verma@intel.com/
> 
> Fix this by adding device address range and node information from
> NVDIMMs to the SRAT in build_srat().
> 
> The relevant command line options to exercise this are below. Nodes 0-1
> contain CPUs and regular memory, and nodes 2-3 are the NVDIMM address
> space.
> 
>   -numa node,nodeid=0,mem=2048M,
>   -numa node,nodeid=1,mem=2048M,
>   -numa node,nodeid=2,mem=0,
>   -object memory-backend-file,id=nvmem0,share,mem-path=nvdimm-0,size=16384M,align=128M
>   -device nvdimm,memdev=nvmem0,id=nv0,label-size=2M,node=2
>   -numa node,nodeid=3,mem=0,
>   -object memory-backend-file,id=nvmem1,share,mem-path=nvdimm-1,size=16384M,align=128M
>   -device nvdimm,memdev=nvmem1,id=nv1,label-size=2M,node=3
> 
> Cc: Jingqi Liu <jingqi.liu@intel.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: Jingqi Liu <jingqi.liu@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
> ---
>  hw/acpi/nvdimm.c        | 26 ++++++++++++++++++++++++++
>  hw/i386/acpi-build.c    | 10 ++++++++++
>  include/hw/mem/nvdimm.h |  1 +
>  3 files changed, 37 insertions(+)
> 
> diff --git a/hw/acpi/nvdimm.c b/hw/acpi/nvdimm.c
> index 9316d12b70..d322c6a7a7 100644
> --- a/hw/acpi/nvdimm.c
> +++ b/hw/acpi/nvdimm.c
> @@ -28,6 +28,7 @@
>  
>  #include "qemu/osdep.h"
>  #include "qemu/uuid.h"
> +#include "qapi/error.h"
>  #include "hw/acpi/acpi.h"
>  #include "hw/acpi/aml-build.h"
>  #include "hw/acpi/bios-linker-loader.h"
> @@ -1334,6 +1335,31 @@ static void nvdimm_build_ssdt(GArray *table_offsets, GArray *table_data,
>      free_aml_allocator();
>  }
>  
> +void *nvdimm_build_srat(GArray *table_data)
> +{
> +    AcpiSratMemoryAffinity *numamem = NULL;
> +    GSList *device_list = nvdimm_get_device_list();
> +
> +    for (; device_list; device_list = device_list->next) {
> +        DeviceState *dev = device_list->data;
I'd use Object here with OBJECT() cast and drop casts beolw in property getters

> +        uint64_t addr, size;
> +        int node;
> +
> +        node = object_property_get_int(OBJECT(dev), PC_DIMM_NODE_PROP,
> +                                       &error_abort);
> +        addr = object_property_get_uint(OBJECT(dev), PC_DIMM_ADDR_PROP,
> +                                        &error_abort);
> +        size = object_property_get_uint(OBJECT(dev), PC_DIMM_SIZE_PROP,
> +                                        &error_abort);
> +
> +        numamem = acpi_data_push(table_data, sizeof *numamem);
> +        build_srat_memory(numamem, addr, size, node,
> +                          MEM_AFFINITY_ENABLED | MEM_AFFINITY_NON_VOLATILE);
> +    }
> +    g_slist_free(device_list);
> +    return numamem;
> +}
> +
>  void nvdimm_build_acpi(GArray *table_offsets, GArray *table_data,
>                         BIOSLinker *linker, NVDIMMState *state,
>                         uint32_t ram_slots)
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 2e15f6848e..1461d8a718 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2428,6 +2428,16 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
>                                MEM_AFFINITY_ENABLED);
>          }
>      }
> +
> +    if (machine->nvdimms_state->is_enabled) {
> +        void *ret;
> +
> +        ret = nvdimm_build_srat(table_data);
> +        if (ret != NULL) {
> +            numamem = ret;
> +        }

why do we need return value here and a test condition and assign 'ret' to numamem?

> +    }
> +
>      slots = (table_data->len - numa_start) / sizeof *numamem;
>      for (; slots < pcms->numa_nodes + 2; slots++) {
>          numamem = acpi_data_push(table_data, sizeof *numamem);
> diff --git a/include/hw/mem/nvdimm.h b/include/hw/mem/nvdimm.h
> index a3c08955e8..fbe56509b8 100644
> --- a/include/hw/mem/nvdimm.h
> +++ b/include/hw/mem/nvdimm.h
> @@ -155,6 +155,7 @@ typedef struct NVDIMMState NVDIMMState;
>  void nvdimm_init_acpi_state(NVDIMMState *state, MemoryRegion *io,
>                              struct AcpiGenericAddress dsm_io,
>                              FWCfgState *fw_cfg, Object *owner);
> +void *nvdimm_build_srat(GArray *table_data);
>  void nvdimm_build_acpi(GArray *table_offsets, GArray *table_data,
>                         BIOSLinker *linker, NVDIMMState *state,
>                         uint32_t ram_slots);