Re: [PATCH v1 3/4] hw/arm/virt-acpi-build: patch guest SRAT for NUMA nodes

[Ankit Agrawal]

>> Ok. I'd failed to register that the bare metal code was doing this though
>> with hindsight I guess that is obvious. Though without more info or
>> a bare metal example being given its also possible the BIOS was doing
>> enumeration etc (like CXL does for all < 2.0 devices) and hence was
>> building SRAT with the necessary memory ranges in place - even if the
>> driver then does the hot add dance later.
>
> Ankit, maybe you can share some relavent ACPI dumps from the physical
> hardware and explain how this compares?

Yeah, we are pretty much emulating the baremetal behavior here (I should have
been clearer). The PXM domains 8-15 are the "device associated" NUMA nodes
on the host. Here are the kernel logs from the baremetal system related to these
NUMA nodes.

[    0.000000] ACPI: SRAT: Node 1 PXM 8 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 2 PXM 9 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 3 PXM 10 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 4 PXM 11 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 5 PXM 12 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 6 PXM 13 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 7 PXM 14 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 8 PXM 15 [mem 0x00000000-0xffffffffffffffff] 
hotplug

...

[    0.000000] Initmem setup node 2 as memoryless
[    0.000000] Initmem setup node 3 as memoryless
[    0.000000] Initmem setup node 4 as memoryless
[    0.000000] Initmem setup node 5 as memoryless
[    0.000000] Initmem setup node 6 as memoryless
[    0.000000] Initmem setup node 7 as memoryless
[    0.000000] Initmem setup node 8 as memoryless
[    0.000000] Initmem setup node 9 as memoryless



On the VM, it looks like the following with the PXM 2-9 associated with the 
device.

[    0.000000] ACPI: SRAT: Node 2 PXM 2 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 3 PXM 3 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 4 PXM 4 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 5 PXM 5 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 6 PXM 6 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 7 PXM 7 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 8 PXM 8 [mem 0x00000000-0xffffffffffffffff] 
hotplug
[    0.000000] ACPI: SRAT: Node 9 PXM 9 [mem 0x00000000-0xffffffffffffffff] 
hotplug