From 0f203430dd88cc6270310956ace58aca639edb59 Mon Sep 17 00:00:00 2001 From: He Chen Date: Thu, 27 Apr 2017 10:35:58 +0800 Subject: 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 Message-Id: <1493260558-20728-1-git-send-email-he.chen@linux.intel.com> Reviewed-by: Igor Mammedov Reviewed-by: Andrew Jones Signed-off-by: Eduardo Habkost --- qemu-options.hx | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'qemu-options.hx') diff --git a/qemu-options.hx b/qemu-options.hx index 70c0ded12e..e10c1454d1 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -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}, -- cgit v1.2.1