Re: [Qemu-devel] [PATCH v2 30/31] pc: ACPI BIOS: reserve SRAT entry for hotplug mem hole

[Michael S. Tsirkin]

On Tue, May 20, 2014 at 05:15:33PM +0200, Igor Mammedov wrote:
> Needed for Windows to use hotplugged memory device, otherwise
> it complains that server is not configured for memory hotplug.
> Tests shows that aftewards it uses dynamically provided
> proximity value from _PXM() method if available.
> 
> Signed-off-by: Igor Mammedov <address@hidden>
> ---
>  hw/i386/acpi-build.c |   14 ++++++++++++++
>  1 files changed, 14 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 58e7306..97e3a82 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1199,6 +1199,8 @@ build_srat(GArray *table_data, GArray *linker,
>      uint64_t curnode;
>      int srat_start, numa_start, slots;
>      uint64_t mem_len, mem_base, next_base;
> +    PCMachineState *pcms = PC_MACHINE(qdev_get_machine());
> +    ram_addr_t hotplug_as_size = memory_region_size(&pcms->hotplug_memory);
>  
>      srat_start = table_data->len;
>  
> @@ -1263,6 +1265,18 @@ build_srat(GArray *table_data, GArray *linker,
>          acpi_build_srat_memory(numamem, 0, 0, 0, MEM_AFFINITY_NOFLAGS);
>      }
>  
> +    /*
> +     * Fake entry required by Windows to enable memory hotplug in OS.
> +     * Individual DIMM devices override proximity set here via _PXM method,
> +     * which returns associated with it NUMA node id.

Failed to parse this last sentence. what returns what associated with
what? Maybe split to 3-4 short sentences.

> +     */
> +    if (hotplug_as_size) {
> +        numamem = acpi_data_push(table_data, sizeof *numamem);
> +        acpi_build_srat_memory(numamem, pcms->hotplug_memory_base,
> +                               hotplug_as_size, 0, MEM_AFFINITY_HOTPLUGGABLE 
> |
> +                               MEM_AFFINITY_ENABLED);
> +    }
> +
>      build_header(linker, table_data,
>                   (void *)(table_data->data + srat_start),
>                   "SRAT",
> -- 
> 1.7.1