On Thu, 23 Jun 2022 16:58:28 +0200
Brice Goglin <brice.gog...@inria.fr> wrote:
> The "Memory Proximity Domain Attributes" structure of the ACPI HMAT
> has a "Processor Proximity Domain Valid" flag that is currently
> always set because Qemu -numa requires an initiator=X value
> when hmat=on. Unsetting this flag allows to create more complex
> memory topologies by having multiple best initiators for a single
> memory target.
>
> This patch allows -numa without initiator=X when hmat=on by keeping
> the default value MAX_NODES in numa_state->nodes[i].initiator.
> All places reading numa_state->nodes[i].initiator already check
> whether it's different from MAX_NODES before using it.
>
> Tested with
> qemu-system-x86_64 -accel kvm \
> -machine pc,hmat=on \
> -drive if=pflash,format=raw,file=./OVMF.fd \
> -drive media=disk,format=qcow2,file=efi.qcow2 \
> -smp 4 \
> -m 3G \
> -object memory-backend-ram,size=1G,id=ram0 \
> -object memory-backend-ram,size=1G,id=ram1 \
> -object memory-backend-ram,size=1G,id=ram2 \
> -numa node,nodeid=0,memdev=ram0,cpus=0-1 \
> -numa node,nodeid=1,memdev=ram1,cpus=2-3 \
> -numa node,nodeid=2,memdev=ram2 \
> -numa
> hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,latency=10
> \
> -numa
> hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=10485760
> \
> -numa
> hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,latency=20
> \
> -numa
> hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=5242880
> \
> -numa
> hmat-lb,initiator=0,target=2,hierarchy=memory,data-type=access-latency,latency=30
> \
> -numa
> hmat-lb,initiator=0,target=2,hierarchy=memory,data-type=access-bandwidth,bandwidth=1048576
> \
> -numa
> hmat-lb,initiator=1,target=0,hierarchy=memory,data-type=access-latency,latency=20
> \
> -numa
> hmat-lb,initiator=1,target=0,hierarchy=memory,data-type=access-bandwidth,bandwidth=5242880
> \
> -numa
> hmat-lb,initiator=1,target=1,hierarchy=memory,data-type=access-latency,latency=10
> \
> -numa
> hmat-lb,initiator=1,target=1,hierarchy=memory,data-type=access-bandwidth,bandwidth=10485760
> \
> -numa
> hmat-lb,initiator=1,target=2,hierarchy=memory,data-type=access-latency,latency=30
> \
> -numa
> hmat-lb,initiator=1,target=2,hierarchy=memory,data-type=access-bandwidth,bandwidth=1048576
> which reports NUMA node2 at same distance from both node0 and node1 as seen
> in lstopo:
> Machine (2966MB total) + Package P#0
> NUMANode P#2 (979MB)
> Group0
> NUMANode P#0 (980MB)
> Core P#0 + PU P#0
> Core P#1 + PU P#1
> Group0
> NUMANode P#1 (1007MB)
> Core P#2 + PU P#2
> Core P#3 + PU P#3
>
> Before this patch, we had to add ",initiator=X" to "-numa
> node,nodeid=2,memdev=ram2".
> The lstopo output difference between initiator=1 and no initiator is:
> @@ -1,10 +1,10 @@
> Machine (2966MB total) + Package P#0
> + NUMANode P#2 (979MB)
> Group0
> NUMANode P#0 (980MB)
> Core P#0 + PU P#0
> Core P#1 + PU P#1
> Group0
> NUMANode P#1 (1007MB)
> - NUMANode P#2 (979MB)
> Core P#2 + PU P#2
> Core P#3 + PU P#3
>
> Corresponding changes in the HMAT MPDA structure:
> @@ -49,10 +49,10 @@
> [078h 0120 2] Structure Type : 0000 [Memory Proximity
> Domain Attributes]
> [07Ah 0122 2] Reserved : 0000
> [07Ch 0124 4] Length : 00000028
> -[080h 0128 2] Flags (decoded below) : 0001
> - Processor Proximity Domain Valid : 1
> +[080h 0128 2] Flags (decoded below) : 0000
> + Processor Proximity Domain Valid : 0
> [082h 0130 2] Reserved1 : 0000
> -[084h 0132 4] Attached Initiator Proximity Domain : 00000001
> +[084h 0132 4] Attached Initiator Proximity Domain : 00000080
^^^^^^^^
where does this value come from?
> [088h 0136 4] Memory Proximity Domain : 00000002
> [08Ch 0140 4] Reserved2 : 00000000
> [090h 0144 8] Reserved3 : 0000000000000000
>
> Final HMAT SLLB structures:
> [0A0h 0160 2] Structure Type : 0001 [System Locality Latency
> and Bandwidth Information]
> [0A2h 0162 2] Reserved : 0000
> [0A4h 0164 4] Length : 00000040
> [0A8h 0168 1] Flags (decoded below) : 00
> Memory Hierarchy : 0
> [0A9h 0169 1] Data Type : 00
> [0AAh 0170 2] Reserved1 : 0000
> [0ACh 0172 4] Initiator Proximity Domains # : 00000002
> [0B0h 0176 4] Target Proximity Domains # : 00000003
> [0B4h 0180 4] Reserved2 : 00000000
> [0B8h 0184 8] Entry Base Unit : 0000000000002710
> [0C0h 0192 4] Initiator Proximity Domain List : 00000000
> [0C4h 0196 4] Initiator Proximity Domain List : 00000001
> [0C8h 0200 4] Target Proximity Domain List : 00000000
> [0CCh 0204 4] Target Proximity Domain List : 00000001
> [0D0h 0208 4] Target Proximity Domain List : 00000002
> [0D4h 0212 2] Entry : 0001
> [0D6h 0214 2] Entry : 0002
> [0D8h 0216 2] Entry : 0003
> [0DAh 0218 2] Entry : 0002
> [0DCh 0220 2] Entry : 0001
> [0DEh 0222 2] Entry : 0003
>
> [0E0h 0224 2] Structure Type : 0001 [System Locality Latency
> and Bandwidth Information]
> [0E2h 0226 2] Reserved : 0000
> [0E4h 0228 4] Length : 00000040
> [0E8h 0232 1] Flags (decoded below) : 00
> Memory Hierarchy : 0
> [0E9h 0233 1] Data Type : 03
> [0EAh 0234 2] Reserved1 : 0000
> [0ECh 0236 4] Initiator Proximity Domains # : 00000002
> [0F0h 0240 4] Target Proximity Domains # : 00000003
> [0F4h 0244 4] Reserved2 : 00000000
> [0F8h 0248 8] Entry Base Unit : 0000000000000001
> [100h 0256 4] Initiator Proximity Domain List : 00000000
> [104h 0260 4] Initiator Proximity Domain List : 00000001
> [108h 0264 4] Target Proximity Domain List : 00000000
> [10Ch 0268 4] Target Proximity Domain List : 00000001
> [110h 0272 4] Target Proximity Domain List : 00000002
> [114h 0276 2] Entry : 000A
> [116h 0278 2] Entry : 0005
> [118h 0280 2] Entry : 0001
> [11Ah 0282 2] Entry : 0005
> [11Ch 0284 2] Entry : 000A
> [11Eh 0286 2] Entry : 0001
>
> Signed-off-by: Brice Goglin <brice.gog...@inria.fr>
> ---
> hw/core/machine.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index a673302cce..d4d7e77401 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -1173,9 +1173,7 @@ static void numa_validate_initiator(NumaState
> *numa_state)
>
> for (i = 0; i < numa_state->num_nodes; i++) {
> if (numa_info[i].initiator == MAX_NODES) {
> - error_report("The initiator of NUMA node %d is missing, use "
> - "'-numa node,initiator' option to declare it", i);
> - exit(1);
> + continue;
> }
>
> if (!numa_info[numa_info[i].initiator].present) {
