Merge tag 'mem-2023-11-13' of https://github.com/davidhildenbrand/qemu …

…into staging

Hi,

"Host Memory Backends" and "Memory devices" queue ("mem"):
- One virtio-mem fix leading to a QEMU crash in QEMU debug builds

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# gpg: Signature made Mon 13 Nov 2023 03:37:15 EST
# gpg:                using RSA key 1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A
# gpg:                issuer "david@redhat.com"
# gpg: Good signature from "David Hildenbrand <david@redhat.com>" [unknown]
# gpg:                 aka "David Hildenbrand <davidhildenbrand@gmail.com>" [full]
# gpg:                 aka "David Hildenbrand <hildenbr@in.tum.de>" [unknown]
# gpg: WARNING: The key's User ID is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 1BD9 CAAD 735C 4C3A 460D  FCCA 4DDE 10F7 00FF 835A

* tag 'mem-2023-11-13' of https://github.com/davidhildenbrand/qemu:
  virtio-mem: fix division by zero in virtio_mem_activate_memslots_to_plug()

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

hw/virtio/virtio-mem.c

@@ -525,9 +525,7 @@ static void virtio_mem_activate_memslots_to_plug(VirtIOMEM *vmem,
                                  vmem->memslot_size;
     unsigned int idx;
 
-    if (!vmem->dynamic_memslots) {
-        return;
-    }
+    assert(vmem->dynamic_memslots);
 
     /* Activate all involved memslots in a single transaction. */
     memory_region_transaction_begin();
@@ -547,9 +545,7 @@ static void virtio_mem_deactivate_unplugged_memslots(VirtIOMEM *vmem,
                                  vmem->memslot_size;
     unsigned int idx;
 
-    if (!vmem->dynamic_memslots) {
-        return;
-    }
+    assert(vmem->dynamic_memslots);
 
     /* Deactivate all memslots with unplugged blocks in a single transaction. */
     memory_region_transaction_begin();
@@ -598,7 +594,9 @@ static int virtio_mem_set_block_state(VirtIOMEM *vmem, uint64_t start_gpa,
         virtio_mem_notify_unplug(vmem, offset, size);
         virtio_mem_set_range_unplugged(vmem, start_gpa, size);
         /* Deactivate completely unplugged memslots after updating the state. */
-        virtio_mem_deactivate_unplugged_memslots(vmem, offset, size);
+        if (vmem->dynamic_memslots) {
+            virtio_mem_deactivate_unplugged_memslots(vmem, offset, size);
+        }
         return 0;
     }
 
@@ -635,9 +633,11 @@ static int virtio_mem_set_block_state(VirtIOMEM *vmem, uint64_t start_gpa,
          * blocks we are plugging here. The following notification will inform
          * registered listeners about the blocks we're plugging.
          */
-        virtio_mem_activate_memslots_to_plug(vmem, offset, size);
+        if (vmem->dynamic_memslots) {
+            virtio_mem_activate_memslots_to_plug(vmem, offset, size);
+        }
         ret = virtio_mem_notify_plug(vmem, offset, size);
-        if (ret) {
+        if (ret && vmem->dynamic_memslots) {
             virtio_mem_deactivate_unplugged_memslots(vmem, offset, size);
         }
     }
@@ -749,7 +749,9 @@ static int virtio_mem_unplug_all(VirtIOMEM *vmem)
         notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
 
         /* Deactivate all memslots after updating the state. */
-        virtio_mem_deactivate_unplugged_memslots(vmem, 0, region_size);
+        if (vmem->dynamic_memslots) {
+            virtio_mem_deactivate_unplugged_memslots(vmem, 0, region_size);
+        }
     }
 
     trace_virtio_mem_unplugged_all();