On 5/1/2022 1:25 am, Sean Christopherson wrote:
On Fri, Dec 31, 2021, Like Xu wrote:
On 31/12/2021 2:13 am, Sean Christopherson wrote:
On Fri, Dec 10, 2021, Like Xu wrote:
The new hardware facility supporting guest PEBS is only available on
Intel Ice Lake Server platforms for now. KVM will check this field
through perf_get_x86_pmu_capability() instead of hard coding the cpu
models in the KVM code. If it is supported, the guest PEBS capability
will be exposed to the guest.
So what exactly is this new feature? I've speed read the cover letter and a few
changelogs and didn't find anything that actually explained when this feature does.
Please check Intel SDM Vol3 18.9.5 for this "EPT-Friendly PEBS" feature.
I assume when an unfamiliar feature appears in the patch SUBJECT,
the reviewer may search for the exact name in the specification.
C'mon, seriously? How the blazes am I supposed to know that the feature name
is EPT-Friendly PEBS? Or that it's even in the SDM (it's not in the year-old
version of the SDM I currently have open) versus one of the many ISE docs?
You're right. The reviewer's time is valuable. Apologies for my wrong assumption.
This is not hard. Please spend the 30 seconds it takes to write a small blurb
so that reviewers don't have to spend 5+ minutes wondering WTF this does.
Add support for EPT-Friendly PEBS, a new CPU feature that enlightens PEBS to
translate guest linear address through EPT, and facilitates handling VM-Exits
that occur when accessing PEBS records. More information can be found in the
<date> release of Intel's SDM, Volume 3, 18.9.5 "EPT-Friendly PEBS".
Applied and thanks.
