[PATCH 3/4] virtio-mem: Implement Resettable interface instead of using LegacyReset

[Juraj Marcin <jmarcin@redhat.com>]

LegacyReset does not pass ResetType to the reset callback method, which
the new Resettable interface uses. Due to this, virtio-mem cannot use
the new RESET_TYPE_WAKEUP to skip reset during wake-up from a suspended
state.

This patch adds the Resettable interface to the VirtioMemClass interface
list, implements the necessary methods and replaces
qemu_[un]register_reset() calls with qemu_[un]register_resettable().

Signed-off-by: Juraj Marcin <jmarcin@redhat.com>
---
 hw/virtio/virtio-mem.c         | 39 ++++++++++++++++++++++------------
 include/hw/virtio/virtio-mem.h |  4 ++++
 2 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index ef64bf1b4a..4f2fd7dc2e 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -895,18 +895,6 @@ static int virtio_mem_validate_features(VirtIODevice *vdev)
     return 0;
 }
 
-static void virtio_mem_system_reset(void *opaque)
-{
-    VirtIOMEM *vmem = VIRTIO_MEM(opaque);
-
-    /*
-     * During usual resets, we will unplug all memory and shrink the usable
-     * region size. This is, however, not possible in all scenarios. Then,
-     * the guest has to deal with this manually (VIRTIO_MEM_REQ_UNPLUG_ALL).
-     */
-    virtio_mem_unplug_all(vmem);
-}
-
 static void virtio_mem_prepare_mr(VirtIOMEM *vmem)
 {
     const uint64_t region_size = memory_region_size(&vmem->memdev->mr);
@@ -1123,7 +1111,7 @@ static void virtio_mem_device_realize(DeviceState *dev, Error **errp)
         vmstate_register_any(VMSTATE_IF(vmem),
                              &vmstate_virtio_mem_device_early, vmem);
     }
-    qemu_register_reset(virtio_mem_system_reset, vmem);
+    qemu_register_resettable(OBJECT(vmem));
 
     /*
      * Set ourselves as RamDiscardManager before the plug handler maps the
@@ -1143,7 +1131,7 @@ static void virtio_mem_device_unrealize(DeviceState *dev)
      * found via an address space anymore. Unset ourselves.
      */
     memory_region_set_ram_discard_manager(&vmem->memdev->mr, NULL);
-    qemu_unregister_reset(virtio_mem_system_reset, vmem);
+    qemu_unregister_resettable(OBJECT(vmem));
     if (vmem->early_migration) {
         vmstate_unregister(VMSTATE_IF(vmem), &vmstate_virtio_mem_device_early,
                            vmem);
@@ -1843,12 +1831,31 @@ static void virtio_mem_unplug_request_check(VirtIOMEM *vmem, Error **errp)
     }
 }
 
+static ResettableState *virtio_mem_get_reset_state(Object *obj)
+{
+    VirtIOMEM *vmem = VIRTIO_MEM(obj);
+    return &vmem->reset_state;
+}
+
+static void virtio_mem_system_reset_hold(Object *obj, ResetType type)
+{
+    VirtIOMEM *vmem = VIRTIO_MEM(obj);
+
+    /*
+     * During usual resets, we will unplug all memory and shrink the usable
+     * region size. This is, however, not possible in all scenarios. Then,
+     * the guest has to deal with this manually (VIRTIO_MEM_REQ_UNPLUG_ALL).
+     */
+    virtio_mem_unplug_all(vmem);
+}
+
 static void virtio_mem_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
     VirtIOMEMClass *vmc = VIRTIO_MEM_CLASS(klass);
     RamDiscardManagerClass *rdmc = RAM_DISCARD_MANAGER_CLASS(klass);
+    ResettableClass *rc = RESETTABLE_CLASS(klass);
 
     device_class_set_props(dc, virtio_mem_properties);
     dc->vmsd = &vmstate_virtio_mem;
@@ -1875,6 +1882,9 @@ static void virtio_mem_class_init(ObjectClass *klass, void *data)
     rdmc->replay_discarded = virtio_mem_rdm_replay_discarded;
     rdmc->register_listener = virtio_mem_rdm_register_listener;
     rdmc->unregister_listener = virtio_mem_rdm_unregister_listener;
+
+    rc->get_state = virtio_mem_get_reset_state;
+    rc->phases.hold = virtio_mem_system_reset_hold;
 }
 
 static const TypeInfo virtio_mem_info = {
@@ -1887,6 +1897,7 @@ static const TypeInfo virtio_mem_info = {
     .class_size = sizeof(VirtIOMEMClass),
     .interfaces = (InterfaceInfo[]) {
         { TYPE_RAM_DISCARD_MANAGER },
+        { TYPE_RESETTABLE_INTERFACE },
         { }
     },
 };
diff --git a/include/hw/virtio/virtio-mem.h b/include/hw/virtio/virtio-mem.h
index 5f5b02b8f9..79f197216b 100644
--- a/include/hw/virtio/virtio-mem.h
+++ b/include/hw/virtio/virtio-mem.h
@@ -13,6 +13,7 @@
 #ifndef HW_VIRTIO_MEM_H
 #define HW_VIRTIO_MEM_H
 
+#include "hw/resettable.h"
 #include "standard-headers/linux/virtio_mem.h"
 #include "hw/virtio/virtio.h"
 #include "qapi/qapi-types-misc.h"
@@ -115,6 +116,9 @@ struct VirtIOMEM {
 
     /* listeners to notify on plug/unplug activity. */
     QLIST_HEAD(, RamDiscardListener) rdl_list;
+
+    /* State of the resettable container */
+    ResettableState reset_state;
 };
 
 struct VirtIOMEMClass {
-- 
2.45.2