On 25/05/2022 09:13, Roger Pau Monne wrote: > Rename the flag to better note that it's not actually forcing any IPIs > to be issued if none is required, but merely avoiding the usage of TLB > flush assistance (which itself can avoid the sending of IPIs to remote > processors). > > No functional change expected. > > Requested-by: Jan Beulich <[email protected]> > Signed-off-by: Roger Pau Monné <[email protected]> > --- > Changes since v2: > - New in this version.
:( This needs reverting. It is specific to IPIs, because of our current choice of algorithm for freeing pagetables. "no assist" excludes ipi-helper hypercalls which invoke INVALIDATE_TLB_VECTOR. Such hypercalls do exist and specifically would be improvement that we ought to use. Furthermore, we do want to work around the limitation that created FLUSH_FORCE_IPI, because we absolutely do want to be able to use hypercalls/remote TLB flushing capabilities when available. I accept that FORCE_IPI perhaps isn't a perfect name, but it's a whole lot less bad than NO_ASSIST. ~Andrew
