diff options
| author | Serhii Popovych <spopovyc@redhat.com> | 2018-11-22 08:19:27 -0500 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2018-12-21 09:24:23 +1100 |
| commit | 3908a24fcb83913079d315de0ca6d598e8616dbb (patch) | |
| tree | 356e7109538d1c25d731cae9565323dd6b7f8d66 /hw/ppc/spapr.c | |
| parent | 6187ec05edc240204935fdf0d89cded563fdeab4 (diff) | |
spapr: Fix ibm,max-associativity-domains property number of nodes
Laurent Vivier reported off by one with maximum number of NUMA nodes
provided by qemu-kvm being less by one than required according to
description of "ibm,max-associativity-domains" property in LoPAPR.
It appears that I incorrectly treated LoPAPR description of this
property assuming it provides last valid domain (NUMA node here)
instead of maximum number of domains.
### Before hot-add
(qemu) info numa
3 nodes
node 0 cpus: 0
node 0 size: 0 MB
node 0 plugged: 0 MB
node 1 cpus:
node 1 size: 1024 MB
node 1 plugged: 0 MB
node 2 cpus:
node 2 size: 0 MB
node 2 plugged: 0 MB
$ numactl -H
available: 2 nodes (0-1)
node 0 cpus: 0
node 0 size: 0 MB
node 0 free: 0 MB
node 1 cpus:
node 1 size: 999 MB
node 1 free: 658 MB
node distances:
node 0 1
0: 10 40
1: 40 10
### Hot-add
(qemu) object_add memory-backend-ram,id=mem0,size=1G
(qemu) device_add pc-dimm,id=dimm1,memdev=mem0,node=2
(qemu) [ 87.704898] pseries-hotplug-mem: Attempting to hot-add 4 ...
<there is no "Initmem setup node 2 [mem 0xHEX-0xHEX]">
[ 87.705128] lpar: Attempting to resize HPT to shift 21
... <HPT resize messages>
### After hot-add
(qemu) info numa
3 nodes
node 0 cpus: 0
node 0 size: 0 MB
node 0 plugged: 0 MB
node 1 cpus:
node 1 size: 1024 MB
node 1 plugged: 0 MB
node 2 cpus:
node 2 size: 1024 MB
node 2 plugged: 1024 MB
$ numactl -H
available: 2 nodes (0-1)
^^^^^^^^^^^^^^^^^^^^^^^^
Still only two nodes (and memory hot-added to node 0 below)
node 0 cpus: 0
node 0 size: 1024 MB
node 0 free: 1021 MB
node 1 cpus:
node 1 size: 999 MB
node 1 free: 658 MB
node distances:
node 0 1
0: 10 40
1: 40 10
After fix applied numactl(8) reports 3 nodes available and memory
plugged into node 2 as expected.
From David Gibson:
------------------
Qemu makes a distinction between "non NUMA" (nb_numa_nodes == 0) and
"NUMA with one node" (nb_numa_nodes == 1). But from a PAPR guests's
point of view these are equivalent. I don't want to present two
different cases to the guest when we don't need to, so even though the
guest can handle it, I'd prefer we put a '1' here for both the
nb_numa_nodes == 0 and nb_numa_nodes == 1 case.
This consolidates everything discussed previously on mailing list.
Fixes: da9f80fbad21 ("spapr: Add ibm,max-associativity-domains property")
Reported-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Serhii Popovych <spopovyc@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Diffstat (limited to 'hw/ppc/spapr.c')
| -rw-r--r-- | hw/ppc/spapr.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index 55be0f56cb..b423db311e 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -1033,7 +1033,7 @@ static void spapr_dt_rtas(sPAPRMachineState *spapr, void *fdt) cpu_to_be32(0), cpu_to_be32(0), cpu_to_be32(0), - cpu_to_be32(nb_numa_nodes ? nb_numa_nodes - 1 : 0), + cpu_to_be32(nb_numa_nodes ? nb_numa_nodes : 1), }; _FDT(rtas = fdt_add_subnode(fdt, 0, "rtas")); |