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authorPaolo Bonzini <pbonzini@redhat.com>2018-10-04 17:12:45 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2018-10-04 17:12:45 +0200
commitdd5bd0a65ff6f22a32b35ca3fa1bcf7a6bc7104f (patch)
tree7214fc9fb55a1cedee4d0bca3a4f6799414236e7 /arch/s390/mm
parent7e7126846c95a34f98a1524d5c473af1f0783735 (diff)
parent55d09dd4c86060fbbc74ab2b1bfaed401cd0163a (diff)
Merge tag 'kvm-s390-next-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: Features for 4.20 - Initial version of AP crypto virtualization via vfio-mdev - Set the host program identifier - Optimize page table locking
Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/gmap.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 911c7ded35f1..1e668b95e0c6 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -907,10 +907,16 @@ static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr)
pmd_t *pmdp;
BUG_ON(gmap_is_shadow(gmap));
- spin_lock(&gmap->guest_table_lock);
pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1);
+ if (!pmdp)
+ return NULL;
- if (!pmdp || pmd_none(*pmdp)) {
+ /* without huge pages, there is no need to take the table lock */
+ if (!gmap->mm->context.allow_gmap_hpage_1m)
+ return pmd_none(*pmdp) ? NULL : pmdp;
+
+ spin_lock(&gmap->guest_table_lock);
+ if (pmd_none(*pmdp)) {
spin_unlock(&gmap->guest_table_lock);
return NULL;
}