Re: Xen 4.2 Release Plan / TODO

[Matt Wilson <msw@amazon.com>]

On Tue, Jun 26, 2012 at 01:39:42AM -0700, Ian Campbell wrote:
>     * [BUG] vcpu-set doesn't take effect on guest, reported by Intel:
>       http://bugzilla.xen.org/bugzilla/show_bug.cgi?id=1822

This may be a problem with the guest, rather than a problem with Xen
or the toolstack. I tested on a domU running a 3.2.20-based Linux
kernel. The domU kernel didn't automatically enable the vCPUs after
calling "xl vcpu-set" to increase the allocation.

# xl list 2
Name                                        ID   Mem VCPUs      State Time(s)
test                                         2 15360     1     -b---- 6617.6
# xl vcpu-set 2 4
# xl list 2
Name                                        ID   Mem VCPUs      State Time(s)
test                                         2 15360     1     -b---- 6617.7

But when I hotplugged the CPUs on the domU side with

  for online in /sys/devices/system/cpu/cpu*/online; do
      echo 1 > $online
  done

Now we see:

# xl list 2
Name                                        ID   Mem VCPUs      State Time(s)
test                                         2 15360     4     -b---- 6617.8

I've added this as a comment to the bugzilla.

Matt