On Mon, Nov 16, 2015 at 10:44:59AM +0100, Paolo Bonzini wrote:
On 13/11/2015 20:07, Eduardo Habkost wrote:
KVM can't virtualize rdtscp on AMD CPUs yet, so there's no point in enabling it by default on AMD CPU models, as all we are getting are confused users because of the "host doesn't support requested feature" warnings.
Disable rdtscp on Opteron_G* models, but keep compatibility on pc-*-2.4 and older (just in case there are people are doing funny stuff using AMD CPU models on Intel hosts).
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Can we do it only on KVM and not on TCG?
We can, but I would like to avoid it, if possible. It would require more complex compat code (the "Add optional class name to kvm_default_props¨ patch I sent some time ago), and people who need rdtscp will be able to use Opteron_G*-rdtscp soon. -- Eduardo