Commit 3ae11dbc authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Heiko Carstens
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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: default avatarChristian Borntraeger <borntraeger@linux.ibm.com>
Suggested-by: default avatarJanis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220530092706.11637-3-borntraeger@linux.ibm.com


Signed-off-by: default avatarChristian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 6d594627

arch/s390/mm/pgtable.c

+1 −1
Original line number Diff line number Diff line
@@ -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();

}