Re: [PATCH 00/13] More parallel operations for the TDP MMU

From: Paolo Bonzini
Date: Thu Apr 01 2021 - 06:44:30 EST


On 31/03/21 23:08, Ben Gardon wrote:
Now that the TDP MMU is able to handle page faults in parallel, it's a
relatively small change to expand to other operations. This series allows
zapping a range of GFNs, reclaiming collapsible SPTEs (when disabling
dirty logging), and enabling dirty logging to all happen under the MMU
lock in read mode.

This is partly a cleanup + rewrite of the last few patches of the parallel
page faults series. I've incorporated feedback from Sean and Paolo, but
the patches have changed so much that I'm sending this as a separate
series.

Ran kvm-unit-tests + selftests on an SMP kernel + Intel Skylake, with the
TDP MMU enabled and disabled. This series introduces no new failures or
warnings.

I know this will conflict horribly with the patches from Sean's series
which were just queued, and I'll send a v2 to fix those conflicts +
address any feedback on this v1.

Mostly looks good (the only substantial remark is from Sean's reply to patch 7); I've made a couple adjustments to the patches I had queued to ease the fixing of conflicts. The patches should hit kvm/queue later today, right after I send my 5.11 pull request to Linus.

I have also just sent a completely unrelated remark on the existing page fault function, which was prompted by reviewing these patches. If you agree, I can take care of the change or you can include it in v2, as you prefer (I don't expect conflicts).

Paolo