tree faaeb4b7127734ecff67d716c0d655efc4b6a873
parent d4f205ea2ff2800b253d4681afaa6af330bfa33b
author Andreas Sandberg <andreas@sandberg.pp.se> 1381824563 +0200
committer Andreas Sandberg <andreas@sandberg.pp.se> 1381824563 +0200

kvm: Set the perf exclude_host attribute if available

The performance counting framework in Linux 3.2 and onwards supports
an attribute to exclude events generated by the host when running
KVM. Setting this attribute allows us to get more reliable
measurements of the guest machine. For example, on a highly loaded
system, the instruction counts from the guest can be severely
distorted by the host kernel (e.g., by page fault handlers).

This changeset introduces a check for the attribute and enables it in
the KVM CPU if present.