On 2019/4/12 21:25, Daniel P. Berrangé wrote:
On Fri, Apr 12, 2019 at 08:37:49PM +0800, Pu Wen wrote:
Add two new base CPU models called 'Dhyana' and 'Dhyana-IBPB' to model
processors from Hygon Dhyana (family 18h), which derived from AMD EPYC
(family 17h). 'Dhyana-IBPB' is a copy of the 'Dhyana' CPU model with
just CPUID_8000_0008_EBX_IBPB added.
...
The Google results I see suggest that Dhyana CPUs started to become
available in July 2018, so surely they would come with microcode
that has the IBPB right from day 1 ?
Yes, you are right. Dhyana CPUs already have the IBPB feature.
Am I missing anything that means there will be a compelling need
to support Dhyana /without/ IBPB ?
If not, then we only need 1 CPU model and that would include IBPB.
Okay, will only keep one CPU model which include IBPB by using the name
'Dhyana'.
Thx.
--
Regards,
Pu Wen
