This patch adds a new domain config option, 'cpus' which is a list of

CPUs a domains' vcpus can use.  The older 'cpu' config option is
prepended to the list of cpus to use and will keep the behavior of
pinning VCPU0.

The cpus option supports ranges and negation, so:

cpus = "0-3,5,^1" produces -> [0,2,3,5]

The list is circular, so in a domain with the following config:

vcpus = 4
cpus  = "0,3,7"  # Use any of 0, 3, 7 for this domain.

would see vcpus 0-3 pinned to cpus 0,3,7,0 respectively.

Also, the pin operation is moved before the memory reservation as vcpu
to cpu mapping will be helpful for future NUMA work when trying to
allocate pages close to the physical cpus being used.

An update to the display of cpumap was needed to normalize the cpumap
values to the range of possible cpus.

I've also included some text for the xmdomain.cfg(5) man page.

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/docs/man/xmdomain.cfg.pod.5 b/docs/man/xmdomain.cfg.pod.5
index 4b9a35a446..df868543b1 100644
--- a/docs/man/xmdomain.cfg.pod.5
+++ b/docs/man/xmdomain.cfg.pod.5
@@ -156,6 +156,16 @@ Specifies which CPU the domain should be started on, where 0 specifies
 the first cpu, 1 the second, and so on.  This defaults to -1, which
 means Xen is free to pick which CPU to start on.
 
+=item B<cpus>
+
+Specifies a list of CPUs on which the domains' VCPUs are allowed to
+execute upon.  The syntax supports ranges (0-3), and negation, ^1.
+For instance:
+
+    cpus = "0-3,5,^1"
+
+Will result in CPUs 0, 2, 3, 5 being available for use by the domain.
+
 =item B<extra>
 
 Extra information to append to the end of the kernel parameter line.