Re: [libvirt] [PATCH v4 0/8] CPU Model Baseline and Comparison for s390x
On 8/20/19 10:06 AM, Jiri Denemark wrote:
First, let me apologize for such a late review. I'll try my best
to
review your series earlier next time.
Your review is greatly appreciated! I haven't replied to your other
posts on this series as my comments were mostly acknowledgements rather
than discussion pieces. I'm working through them.
On Wed, Jul 17, 2019 at 10:03:21 -0400, Collin Walling wrote:
> When baselining CPU models and the user appends the --features argument
> to the command, s390x will only report back features that supersede the
> base model definition.
>
> *NOTE* if the --features flag is intended to expand /ALL/ features
> available to a CPU model (such as the huge list of features reported
> by a full CPU model expansion), please let me know and I can resolve
> this.
I'm not sure how well this fits s390 world, but the semantics of
VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES flag is to report all CPU
features which are hidden behind the CPU model. That is, all feature
which you'd get when starting QEMU with just the CPU model name and no
additional features. The extra features should not be touched at all.
Specifically, removing them when the flag is not used is wrong.
To me this looks like the flag should really result in running
query-cpu-model-expansion (but likely the "static" one rather then
"full" expansion) on the baseline CPU model and reporting the enabled
features along with those already included in the baseline feature set.
Actually, query-cpu-model-baseline will return a CPU model along with a
feature set. The features returned are the same as those produced from a
static expansion on the model.
Correct me if I am wrong here: virsh should report features *only* if the
--features flag is present. Otherwise, we only report the model name (which
can be accomplished by stripping the result of all reported features).
Jirka
--
libvir-list mailing list
libvir-list(a)redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list
Thank you for your review!
--
Respectfully,
- Collin Walling