On 2020-11-27 17:24, Quentin Perret wrote:
On Friday 27 Nov 2020 at 17:14:11 (+0000), Marc Zyngier wrote:
[...]
Yeah, the sanitized read feels better, if only because that is
what we are going to read in all the valid cases, unfortunately.
read_sanitised_ftr_reg() is sadly not designed to be called on
a fast path, meaning that 32bit guests will do a bsearch() on
the ID-regs every time they exit...
I guess we will have to evaluate how much we loose with this.
Could we use the trick we have for arm64_ftr_reg_ctrel0 to speed this
up?
Maybe. I want to first verify whether this has any measurable impact.
Another possibility would be to cache the last read_sanitised_ftr_reg()
access, just to see if that helps. There shouldn't be that many code
paths hammering it.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
