KVM: s390: Fix handle_sske page fault handling

If handle_sske cannot set the storage key, because there is no
page table entry or no present large page entry, it calls
fixup_user_fault.
However, currently, if the call succeeds, handle_sske returns
-EAGAIN, without having set the storage key.
Instead, retry by continue'ing the loop without incrementing the
address.
The same issue in handle_pfmf was fixed by
a11bdb1a6b78 ("KVM: s390: Fix pfmf and conditional skey emulation").

Fixes: bd096f644319 ("KVM: s390: Add skey emulation fault handling")
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20211022152648.26536-1-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 53da4ce..417154b 100644 (file)
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -397,6 +397,8 @@ static int handle_sske(struct kvm_vcpu *vcpu)
                mmap_read_unlock(current->mm);
                if (rc == -EFAULT)
                        return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+               if (rc == -EAGAIN)
+                       continue;
                if (rc < 0)
                        return rc;
                start += PAGE_SIZE;