s390x/pv: prepare for memory devices

Let's avoid checking for the maxram_size, and instead rely on the memory
limit determined in s390_memory_init(), that might be larger than
maxram_size, for example due to alignment purposes.

This check now correctly mimics what the kernel will check in
kvm_s390_pv_set_aside(), whereby a VM <= 2 GiB VM would end up using
a segment type ASCE.

Message-ID: <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Nina Schoetterl-Glausch <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>

Author: davidhildenbrand

target/s390x/kvm/pv.c

@@ -133,7 +133,7 @@ bool s390_pv_vm_try_disable_async(S390CcwMachineState *ms)
      * If the feature is not present or if the VM is not larger than 2 GiB,
      * KVM_PV_ASYNC_CLEANUP_PREPARE fill fail; no point in attempting it.
      */
-    if ((MACHINE(ms)->ram_size <= 2 * GiB) ||
+    if (s390_get_memory_limit(ms) <= 2 * GiB ||
         !kvm_check_extension(kvm_state, KVM_CAP_S390_PROTECTED_ASYNC_DISABLE)) {
         return false;
     }