Re: [Qemu-devel] [PATCH] pc: ACPI BIOS: use highest NUMA node for hotplug mem hole SRAT entry

[Ladi Prosek]

On Wed, May 24, 2017 at 11:07 AM, Laszlo Ersek <address@hidden> wrote:
> On 05/24/17 10:09, Ladi Prosek wrote:
>> For reasons unknown, Windows won't online all memory, both at command
>> line and hot-plugged later, unless the hotplug mem hole SRAT entry
>> specifies a node greater or equal to the ones where memory is added.
>
> s/greater or equal to/greater *than* or equal to/
>
> Thanks,
> Laszlo
> (always finding the important issues! ;) )

Haha, thanks! Igor, please let me know if you'd like me to send a
corrected version.

>>
>> Using the highest node on the machine makes recent versions of Windows
>> happy.
>>
>> With this example command line:
>>   ... \
>>   -m 1024,slots=4,maxmem=32G \
>>   -numa node,nodeid=0 \
>>   -numa node,nodeid=1 \
>>   -numa node,nodeid=2 \
>>   -numa node,nodeid=3 \
>>   -object memory-backend-ram,size=1G,id=mem-mem1 \
>>   -device pc-dimm,id=dimm-mem1,memdev=mem-mem1,node=1
>>
>> Windows reports a total of 1G of RAM without this commit and the expected
>> 2G with this commit.
>>
>> Signed-off-by: Ladi Prosek <address@hidden>
>> ---
>>  hw/i386/acpi-build.c | 7 +++++--
>>  1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>> index afcadac..9653583 100644
>> --- a/hw/i386/acpi-build.c
>> +++ b/hw/i386/acpi-build.c
>> @@ -2404,14 +2404,17 @@ build_srat(GArray *table_data, BIOSLinker *linker, 
>> MachineState *machine)
>>      }
>>
>>      /*
>> -     * Entry is required for Windows to enable memory hotplug in OS.
>> +     * Entry is required for Windows to enable memory hotplug in OS
>> +     * and for Linux to enable SWIOTLB even if booted with less than
>> +     * 4G of RAM. Windows works better if the entry sets proximity
>> +     * to the highest NUMA node in the machine.
>>       * Memory devices may override proximity set by this entry,
>>       * 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, 0,
>> +                          hotplugabble_address_space_size, pcms->numa_nodes 
>> - 1,
>>                            MEM_AFFINITY_HOTPLUGGABLE | MEM_AFFINITY_ENABLED);
>>      }
>>
>>
>