Re: [PATCH 1/3] KVM: X86: Add "nopvspin" parameter to disable PV spinlocks

From: Zhenzhong Duan
Date: Tue Oct 01 2019 - 05:49:09 EST



On 2019/10/1 16:39, Vitaly Kuznetsov wrote:
Zhenzhong Duan<zhenzhong.duan@xxxxxxxxxx> writes:

On 2019/9/30 23:41, Vitaly Kuznetsov wrote:
Zhenzhong Duan<zhenzhong.duan@xxxxxxxxxx> writes:

There are cases where a guest tries to switch spinlocks to bare metal
behavior (e.g. by setting "xen_nopvspin" on XEN platform and
"hv_nopvspin" on HYPER_V).

That feature is missed on KVM, add a new parameter "nopvspin" to disable
PV spinlocks for KVM guest.

This new parameter is also intended to replace "xen_nopvspin" and
"hv_nopvspin" in the future.
Any reason to not do it right now? We will probably need to have compat
code to support xen_nopvspin/hv_nopvspin too but emit a 'is deprecated'
warning.
Sorry the description isn't clear, I'll fix it.

I did the compat work in the other two patches.
[PATCH 2/3] xen: Mark "xen_nopvspin" parameter obsolete and map it to "nopvspin"
[PATCH 3/3] x86/hyperv: Mark "hv_nopvspin" parameter obsolete and map it to "nopvspin"

For some reason I got CCed only on the first one and moreover,

The three patches have different maintainers/reviewers by get_maintainer.pl, I added
"Cc: maintainers/reviewers" to each patch then git-sendemail picked them automaticly.
I meaned to not disturb maintainers with the field they aren't in charge of. It looks
I'm wrong.

So what's the correct way dealing with this? Should I send the whole patchset to all
the maintainers/reviewers related to all the patches?

I don't see e.g PATCH3 on 'linux-hyperv' mailing list.

Thanks for point out, I'll add it.

Zhenzhong