On Mon, Mar 02, 2020 at 07:47:28PM +0800, Tao Xu wrote:
On 2/29/2020 5:39 AM, Eduardo Habkost wrote:
On Wed, Feb 12, 2020 at 04:13:26PM +0800, Tao Xu wrote:
Add new version of Snowridge, Denverton, Opteron_G3, EPYC, and Dhyana
CPU model to uremove MONITOR/MWAIT featre.
After QEMU/KVM use "-overcommit cpu-pm=on" to expose MONITOR/MWAIT
(commit id 6f131f13e68d648a8e4f083c667ab1acd88ce4cd), the MONITOR/MWAIT
feature in these CPU model is unused.
Signed-off-by: Tao Xu <address@hidden>
What exactly is the problem you are trying to fix?
No CPU model will ever have monitor=on set by default with KVM,
because kvm_default_props has a monitor=off element.
Maybe it is not a fix. For example, when we boot a guest with Denverton
cpu model, guest cannot detect MONITOR/MWAIT and boot with no warning,
because of "monitor=off" by default. The MONITOR/MWAIT feature in these CPU
model is unused,but no harm. I am wondering if we should remove it from
existing CPU models.
As monitor=off is on kvm_default_props, changing the CPU model
table will only affect other accelerators (e.g. TCG, where
MONITOR/MWAIT support is advertised as supported).
We shouldn't be dictating policy for other accelerators just
because KVM doesn't support it. Removing the feature on
kvm_default_props is sufficient.