[PATCH] hmat acpi: Don't require initiator value in -numa when hmat=on

[Brice Goglin]

From: Brice Goglin <Brice.Goglin@inria.fr>

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 initiator=X 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 with 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. And
hmat_build_table_structs() already unset the Valid flag when needed.

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 \

This exposes 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

Signed-off-by: Brice Goglin <Brice.Goglin@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 d856485cb4..9884ef7ac6 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -1012,9 +1012,7 @@ 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) {
-- 
2.30.2

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