[PATCH v2 11/16] hostmem: Factor out common checks into host_memory_backend_validate()

[David Hildenbrand <david@redhat.com>]

All users want to perform similar checks. Lat's factor it out to prepare
for more checks.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 backends/hostmem.c       | 14 ++++++++++++++
 hw/mem/pc-dimm.c         | 12 +++++-------
 hw/misc/ivshmem.c        | 11 ++++-------
 hw/virtio/virtio-mem.c   | 15 +++++----------
 hw/virtio/virtio-pmem.c  | 13 ++++---------
 include/sysemu/hostmem.h |  2 ++
 6 files changed, 34 insertions(+), 33 deletions(-)

diff --git a/backends/hostmem.c b/backends/hostmem.c
index 2c8e4567e1..de37f1bf5d 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -291,6 +291,20 @@ bool host_memory_backend_is_mapped(HostMemoryBackend *backend)
     return backend->is_mapped;
 }
 
+void host_memory_backend_validate(HostMemoryBackend *backend,
+                                  const char *property, Error **errp)
+{
+    char *path = object_get_canonical_path_component(OBJECT(backend));
+
+    if (!backend) {
+        error_setg(errp, "'%s' property is not set", property);
+    } else if (host_memory_backend_is_mapped(backend)) {
+        error_setg(errp, "'%s' property specifies a busy memdev: %s",
+                   property, path);
+    }
+    g_free(path);
+}
+
 #ifdef __linux__
 size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
 {
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 8f50b8afea..9ee634ee89 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -174,16 +174,14 @@ static void pc_dimm_realize(DeviceState *dev, Error **errp)
     PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
     MachineState *ms = MACHINE(qdev_get_machine());
     int nb_numa_nodes = ms->numa_state->num_nodes;
+    Error *err = NULL;
 
-    if (!dimm->hostmem) {
-        error_setg(errp, "'" PC_DIMM_MEMDEV_PROP "' property is not set");
-        return;
-    } else if (host_memory_backend_is_mapped(dimm->hostmem)) {
-        char *path = object_get_canonical_path_component(OBJECT(dimm->hostmem));
-        error_setg(errp, "can't use already busy memdev: %s", path);
-        g_free(path);
+    host_memory_backend_validate(dimm->hostmem, PC_DIMM_MEMDEV_PROP, &err);
+    if (err) {
+        error_propagate(errp, err);
         return;
     }
+
     if (((nb_numa_nodes > 0) && (dimm->node >= nb_numa_nodes)) ||
         (!nb_numa_nodes && dimm->node)) {
         error_setg(errp, "'DIMM property " PC_DIMM_NODE_PROP " has value %"
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index 1a0fad74e1..39bffceadf 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -1035,14 +1035,11 @@ static Property ivshmem_plain_properties[] = {
 static void ivshmem_plain_realize(PCIDevice *dev, Error **errp)
 {
     IVShmemState *s = IVSHMEM_COMMON(dev);
+    Error *err = NULL;
 
-    if (!s->hostmem) {
-        error_setg(errp, "You must specify a 'memdev'");
-        return;
-    } else if (host_memory_backend_is_mapped(s->hostmem)) {
-        char *path = object_get_canonical_path_component(OBJECT(s->hostmem));
-        error_setg(errp, "can't use already busy memdev: %s", path);
-        g_free(path);
+    host_memory_backend_validate(s->hostmem, "memdev", &err);
+    if (err) {
+        error_propagate(errp, err);
         return;
     }
 
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index 2f759578fe..4b7b4cf950 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -414,16 +414,11 @@ static void virtio_mem_device_realize(DeviceState *dev, Error **errp)
     uint64_t page_size;
 
     /* verify the memdev */
-    if (!vm->memdev) {
-        error_setg(&local_err, "'%s' property must be set",
-                   VIRTIO_MEM_MEMDEV_PROP);
-        goto out;
-    } else if (host_memory_backend_is_mapped(vm->memdev)) {
-        char *path = object_get_canonical_path_component(OBJECT(vm->memdev));
-
-        error_setg(&local_err, "can't use already busy memdev: %s", path);
-        g_free(path);
-        goto out;
+    host_memory_backend_validate(vm->memdev, VIRTIO_MEM_MEMDEV_PROP,
+                                 &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
     }
 
     /* verify the node */
diff --git a/hw/virtio/virtio-pmem.c b/hw/virtio/virtio-pmem.c
index 97287e923b..85cb337ed5 100644
--- a/hw/virtio/virtio-pmem.c
+++ b/hw/virtio/virtio-pmem.c
@@ -105,16 +105,11 @@ static void virtio_pmem_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOPMEM *pmem = VIRTIO_PMEM(dev);
+    Error *err = NULL;
 
-    if (!pmem->memdev) {
-        error_setg(errp, "virtio-pmem memdev not set");
-        return;
-    }
-
-    if (host_memory_backend_is_mapped(pmem->memdev)) {
-        char *path = object_get_canonical_path_component(OBJECT(pmem->memdev));
-        error_setg(errp, "can't use already busy memdev: %s", path);
-        g_free(path);
+    host_memory_backend_validate(pmem->memdev, "memdev", &err);
+    if (err) {
+        error_propagate(errp, err);
         return;
     }
 
diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h
index 4dbdadd39e..d4dbf108ca 100644
--- a/include/sysemu/hostmem.h
+++ b/include/sysemu/hostmem.h
@@ -65,6 +65,8 @@ MemoryRegion *host_memory_backend_get_memory(HostMemoryBackend *backend);
 
 void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped);
 bool host_memory_backend_is_mapped(HostMemoryBackend *backend);
+void host_memory_backend_validate(HostMemoryBackend *backend,
+                                  const char *property, Error **errp);
 size_t host_memory_backend_pagesize(HostMemoryBackend *memdev);
 char *host_memory_backend_get_name(HostMemoryBackend *backend);
 
-- 
2.24.1