I have the same problem after upgrading from squeeze to wheezy. Only the first
half of the cores (4 out of 8) are visible to KVM host. I also have AMD
processor on my HP Proliant DL165 G7 (AMD Opteron(tm) Processor 6136).
The taskset workaround doesn't seem to help. The output of taskset indicates it
changes the affinity list:
# taskset -p -c 0-7 8755pid 8755's current affinity list: 0-3pid 8755's new
affinity list: 0-7
but there is no change to the pinning of the cores: only cores 0-3 are used by
KVM guest. Do I need to do something else to get the workaround working?
Installed versions:linux-image-3.2.0-4-amd64: 3.2.46-1+deb7u1libvirt-bin:
0.9.12-11+deb7u1qemu-kvm: 1.1.2+dfsg-6
