KVM: s390: Fix memslot initialization for userspace_addr != 0

Since
commit 854b5338196b1175706e99d63be43a4f8d8ab607
Author: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
    KVM: s390: streamline memslot handling

s390 uses the values of the memslot instead of doing everything in the arch
ioctl handler of the KVM_SET_USER_MEMORY_REGION. Unfortunately we missed to
set the userspace_addr of our memslot due to our s390 ifdef in
__kvm_set_memory_region.
Old s390 userspace launchers did not notice, since they started the guest at
userspace address 0.
Because of CONFIG_DEFAULT_MMAP_MIN_ADDR we now put the guest at 1M userspace,
which does not work. This patch makes sure that new.userspace_addr is set
on s390.
This fix should go in quickly. Nevertheless, looking at the code we should
clean up that ifdef in the long term. Any kernel janitors?

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

virt/kvm/kvm_main.c

@@ -1199,6 +1199,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
 		if (old.npages)
 			kvm_arch_flush_shadow(kvm);
 	}
+#else  /* not defined CONFIG_S390 */
+	new.user_alloc = user_alloc;
+	if (user_alloc)
+		new.userspace_addr = mem->userspace_addr;
 #endif /* not defined CONFIG_S390 */
 
 	if (!npages)