Address @kib's feedback.

Address @kib's feedback.

Address @kib's feedback.

Address @kib's feedback.

Address @markj's feedback.

Address @kib's feedback.

Address @markj's feedback.

No functional changes intended. Since the last revision:

Rebase, address @kib's review feedback, and related clean-up.

Switch the vDSO and syscall codepaths over to a common (and freestanding) version of __vdso_gettc_rdtsc().

Thanks a lot for the review/feedback, @kib! I'm thinking about the questions raised by the init-related item; this revision attempts to address the other items in the meantime.

Initial/partial round of addressing @kib's feedback.

Address @kib's feedback.

Yes, thanks a lot, @kib, for pointing out malloc_domainset_aligned()! Much better! (Doh---I think I did see this a while back but misinterpreted its relative lack of use and absence from malloc(9) as discouraging new uses).

Use malloc_domainset_aligned() as per @kib's suggestion.

Thanks a lot for this latest round of feedback, @royger! Revised accordingly and/or discussion inline.

Address @royger's review feedback.

In D29733#691518, @dch wrote:

shall I just drop 11.* from the port, or do you want to make a patch for x86 & x64 versions?

Thanks for the additional round of feedback!

• Address @royger's review feedback:
  • Disconnect pvclock abstraction from DEVMETHOD etc.
  • Move libc-kernel-shared pvclock.{c,h} content into pvclock.h.
  • Avoid contigmalloc().
• Identify and push more hypervisor-agnostic content into pvclock.{c,h}.
• Minor cleanup (non-functional).

Thanks a lot for your review and feedback; one of the goals is to make it as easy as possible for the XEN PV clock code to piggyback on the vDSO portion of this work, so, your input is greatly appreciated!

Address @royger's review feedback:

• Switch to using the device pager and only allowing one page to be mmaped by /dev/pvclock.
• Attempt to identify and push more of the hypervisor-agnostic content into the hypervisor-agnostic pvclock.{c,h} layer.

In D29733#668703, @me_freebsd_mathieu.digital wrote:

[...]
All of these are for a KVM vm running under qemu version 5.1.0 on Fedora 33 kernel 5.11.12.

Minor changes and cleanup.

In D29733#668321, @me_freebsd_mathieu.digital wrote:

[...]
I applied the patch to my source tree and while compiling and using the kernel works perfectly, compiling libc failed:

In D29531#665407, @stevek wrote:

In D29531#664852, @me_freebsd_mathieu.digital wrote:

So if you tell us you have no idea how long it'll take before you get the green light, I'd be for merging that one and for your review to update/rewrite it.

If you tell us you'll have something before summer, I'd say let's wait for you.

It should be days, maybe less.

Thanks for the review @grehan and @markj! Diff updated as per @markj's feedback.

Incorporate review feedback from @markj.

Thanks for the review, @markj and @cem! Diff updated with @markj's requested changes.

Incorporate review feedback from @markj.

Remove unnecessary assertion.

Thanks a lot for the review and feedback, @markj! Diff updated and question/response added accordingly.

Incorporate @markj's review feedback and style(9)-ize pctestdev_init()'s local variable declarations.

Incorporate @kib's review feedback.

Incorporate @kib's review feedback.

Thanks a lot for the review and feedback, @grehan and @jhb!

Incorporate @jhb's review feedback.