hostmem: introduce host_memory_backend_mr_inited()
We were checking this against memory region size of host memory
backend's mr field to see whether the mr has been inited. This is
efficient but less elegant. Let's make a helper for it to avoid
confusions, along with some notes.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1489151370-15453-2-git-send-email-peterx@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
diff --git a/backends/hostmem.c b/backends/hostmem.c
index 89feb9e..d8faab4 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -237,6 +237,15 @@
backend->prealloc = mem_prealloc;
}
+bool host_memory_backend_mr_inited(HostMemoryBackend *backend)
+{
+ /*
+ * NOTE: We forbid zero-length memory backend, so here zero means
+ * "we haven't inited the backend memory region yet".
+ */
+ return memory_region_size(&backend->mr) != 0;
+}
+
MemoryRegion *
host_memory_backend_get_memory(HostMemoryBackend *backend, Error **errp)
{
diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h
index ecae0cf..ed6a437 100644
--- a/include/sysemu/hostmem.h
+++ b/include/sysemu/hostmem.h
@@ -62,6 +62,7 @@
MemoryRegion mr;
};
+bool host_memory_backend_mr_inited(HostMemoryBackend *backend);
MemoryRegion *host_memory_backend_get_memory(HostMemoryBackend *backend,
Error **errp);