From 419fcdec3c1ff545cd33d90ade99236c9bcc37cc Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Wed, 10 May 2017 13:30:01 +0200 Subject: numa: add '-numa cpu,...' option for property based node mapping legacy cpu to node mapping is using cpu index values to map VCPU to node with help of '-numa node,nodeid=node,cpus=x[-y]' option. However cpu index is internal concept and QEMU users have to guess /reimplement qemu's logic/ to map it to a concrete cpu socket/core/thread to make sane CPUs placement across numa nodes. This patch allows to map cpu objects to numa nodes using the same properties as used for cpus with -device/device_add (socket-id/core-id/thread-id/node-id). At present valid properties/values to address CPUs could be fetched using hotpluggable-cpus monitor/qmp command, it will require user to start qemu twice when creating domain to fetch possible CPUs for a machine type/-smp layout first and then the second time with numa explicit mapping for actual usage. The first step results could be saved and reused to set/change mapping later as far as machine type/-smp stays the same. Proposed impl. supports exact and wildcard matching to simplify CLI and allow to set mapping for a specific cpu or group of cpu objects specified by matched properties. For example: # exact mapping x86 -numa cpu,node-id=x,socket-id=y,core-id=z,thread-id=n # exact mapping SPAPR -numa cpu,node-id=x,core-id=y # wildcard mapping, all cpu objects that match socket-id=y # are mapped to node-id=x -numa cpu,node-id=x,socket-id=y Signed-off-by: Igor Mammedov Message-Id: <1494415802-227633-18-git-send-email-imammedo@redhat.com> Reviewed-by: David Gibson Signed-off-by: Eduardo Habkost --- qemu-options.hx | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'qemu-options.hx') diff --git a/qemu-options.hx b/qemu-options.hx index e10c1454d1..6ffa98097d 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -145,10 +145,12 @@ 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} +@itemx -numa cpu,node-id=@var{node}[,socket-id=@var{x}][,core-id=@var{y}][,thread-id=@var{z}] @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. +Legacy VCPU assignment uses @samp{cpus} option where @var{firstcpu} and @var{lastcpu} are CPU indexes. Each @samp{cpus} option represent a contiguous range of CPU indexes (or a single VCPU if @var{lastcpu} is omitted). A non-contiguous @@ -162,6 +164,24 @@ a NUMA node: -numa node,cpus=0-2,cpus=5 @end example +@samp{cpu} option is a new alternative to @samp{cpus} option +which uses @samp{socket-id|core-id|thread-id} properties to assign +CPU objects to a @var{node} using topology layout properties of CPU. +The set of properties is machine specific, and depends on used +machine type/@samp{smp} options. It could be queried with +@samp{hotpluggable-cpus} monitor command. +@samp{node-id} property specifies @var{node} to which CPU object +will be assigned, it's required for @var{node} to be declared +with @samp{node} option before it's used with @samp{cpu} option. + +For example: +@example +-M pc \ +-smp 1,sockets=2,maxcpus=2 \ +-numa node,nodeid=0 -numa node,nodeid=1 \ +-numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1 +@end example + @samp{mem} assigns a given RAM amount to a node. @samp{memdev} assigns RAM from a given memory backend device to a node. If @samp{mem} and @samp{memdev} are omitted in all nodes, RAM is -- cgit v1.2.1