numa: Allow setting NUMA distance for different NUMA nodes

This patch is going to add SLIT table support in QEMU, and provides
additional option `dist` for command `-numa` to allow user set vNUMA
distance by QEMU command.

With this patch, when a user wants to create a guest that contains
several vNUMA nodes and also wants to set distance among those nodes,
the QEMU command would like:

```
-numa node,nodeid=0,cpus=0 \
-numa node,nodeid=1,cpus=1 \
-numa node,nodeid=2,cpus=2 \
-numa node,nodeid=3,cpus=3 \
-numa dist,src=0,dst=1,val=21 \
-numa dist,src=0,dst=2,val=31 \
-numa dist,src=0,dst=3,val=41 \
-numa dist,src=1,dst=2,val=21 \
-numa dist,src=1,dst=3,val=31 \
-numa dist,src=2,dst=3,val=21 \
```

Signed-off-by: He Chen <he.chen@linux.intel.com>
Message-Id: <1493260558-20728-1-git-send-email-he.chen@linux.intel.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This commit is contained in:
He Chen 2017-04-27 10:35:58 +08:00 committed by Eduardo Habkost
parent 4ed3d478c6
commit 0f203430dd
8 changed files with 215 additions and 5 deletions

View file

@ -139,12 +139,15 @@ ETEXI
DEF("numa", HAS_ARG, QEMU_OPTION_numa,
"-numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
"-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n", QEMU_ARCH_ALL)
"-numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]\n"
"-numa dist,src=source,dst=destination,val=distance\n", QEMU_ARCH_ALL)
STEXI
@item -numa node[,mem=@var{size}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
@itemx -numa node[,memdev=@var{id}][,cpus=@var{firstcpu}[-@var{lastcpu}]][,nodeid=@var{node}]
@itemx -numa dist,src=@var{source},dst=@var{destination},val=@var{distance}
@findex -numa
Define a NUMA node and assign RAM and VCPUs to it.
Set the NUMA distance from a source node to a destination node.
@var{firstcpu} and @var{lastcpu} are CPU indexes. Each
@samp{cpus} option represent a contiguous range of CPU indexes
@ -167,6 +170,17 @@ split equally between them.
@samp{mem} and @samp{memdev} are mutually exclusive. Furthermore,
if one node uses @samp{memdev}, all of them have to use it.
@var{source} and @var{destination} are NUMA node IDs.
@var{distance} is the NUMA distance from @var{source} to @var{destination}.
The distance from a node to itself is always 10. If any pair of nodes is
given a distance, then all pairs must be given distances. Although, when
distances are only given in one direction for each pair of nodes, then
the distances in the opposite directions are assumed to be the same. If,
however, an asymmetrical pair of distances is given for even one node
pair, then all node pairs must be provided distance values for both
directions, even when they are symmetrical. When a node is unreachable
from another node, set the pair's distance to 255.
Note that the -@option{numa} option doesn't allocate any of the
specified resources, it just assigns existing resources to NUMA
nodes. This means that one still has to use the @option{-m},