On Thu, Jun 23, 2022 at 05:15:20PM +0200, Christian Borntraeger wrote: > stable team, please consider > commit 3ae11dbcfac906a8c3a480e98660a823130dc16a > It will noticeable reduce system overhead when this happens on multiple CPUs. > > ----snip---- > commit 3ae11dbcfac906a8c3a480e98660a823130dc16a > s390/mm: use non-quiescing sske for KVM switch to keyed guest > > The switch to a keyed guest does not require a classic sske as the other > guest CPUs are not accessing the key before the switch is complete. > By using the NQ SSKE things are faster especially with multiple guests. > > > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx> > Suggested-by: Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx> > Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> > Link: https://lore.kernel.org/r/20220530092706.11637-3-borntraeger@xxxxxxxxxxxxx > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx> > Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx> > > diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c > index 697df02362af..4909dcd762e8 100644 > --- a/arch/s390/mm/pgtable.c > +++ b/arch/s390/mm/pgtable.c > @@ -748,7 +748,7 @@ void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep) > pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT; > ptev = pte_val(*ptep); > if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE)) > - page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1); > + page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 0); > pgste_set_unlock(ptep, pgste); > preempt_enable(); > } Now queued up to all stable branches (as you didn't mention otherwise...) thanks, greg k-h
