[PATCH v20 19/21] virtio-gpu: Replace finish_unmapping with mapping_state

[Dmitry Osipenko <dmitry.osipenko@collabora.com>]

Allow virtio_gpu_virgl_unmap_resource_blob() to be invoked while async
unmapping is in progress. Do it in preparation to improvement of virtio-gpu
resetting that will require this change.

Suggested-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 hw/display/trace-events       |  2 +-
 hw/display/virtio-gpu-virgl.c | 28 ++++++++++++++++++++++------
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/hw/display/trace-events b/hw/display/trace-events
index e323a82cff24..4bfc457fbac1 100644
--- a/hw/display/trace-events
+++ b/hw/display/trace-events
@@ -39,7 +39,7 @@ virtio_gpu_cmd_res_create_2d(uint32_t res, uint32_t fmt, uint32_t w, uint32_t h)
 virtio_gpu_cmd_res_create_3d(uint32_t res, uint32_t fmt, uint32_t w, uint32_t h, uint32_t d) "res 0x%x, fmt 0x%x, w %d, h %d, d %d"
 virtio_gpu_cmd_res_create_blob(uint32_t res, uint64_t size) "res 0x%x, size %" PRId64
 virtio_gpu_cmd_res_map_blob(uint32_t res, void *vmr, void *mr) "res 0x%x, vmr %p, mr %p"
-virtio_gpu_cmd_res_unmap_blob(uint32_t res, void *mr, bool finish_unmapping) "res 0x%x, mr %p, finish_unmapping %d"
+virtio_gpu_cmd_res_unmap_blob(uint32_t res, void *mr, int mapping_state) "res 0x%x, mr %p, mapping_state %d"
 virtio_gpu_cmd_res_unref(uint32_t res) "res 0x%x"
 virtio_gpu_cmd_res_back_attach(uint32_t res) "res 0x%x"
 virtio_gpu_cmd_res_back_detach(uint32_t res) "res 0x%x"
diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
index 5617740417ba..4a9e956b25df 100644
--- a/hw/display/virtio-gpu-virgl.c
+++ b/hw/display/virtio-gpu-virgl.c
@@ -68,11 +68,17 @@ virgl_get_egl_display(G_GNUC_UNUSED void *cookie)
 #endif
 
 #if VIRGL_VERSION_MAJOR >= 1
+enum virtio_gpu_virgl_hostmem_region_mapping_state {
+    VIRTIO_GPU_MR_MAPPED,
+    VIRTIO_GPU_MR_UNMAP_STARTED,
+    VIRTIO_GPU_MR_UNMAP_COMPLETED,
+};
+
 struct virtio_gpu_virgl_hostmem_region {
     Object parent_obj;
     MemoryRegion mr;
     struct VirtIOGPU *g;
-    bool finish_unmapping;
+    enum virtio_gpu_virgl_hostmem_region_mapping_state mapping_state;
 };
 
 #define TYPE_VIRTIO_GPU_VIRGL_HOSTMEM_REGION "virtio-gpu-virgl-hostmem-region"
@@ -109,7 +115,7 @@ static void virtio_gpu_virgl_hostmem_region_finalize(Object *obj)
         return;
     }
 
-    vmr->finish_unmapping = true;
+    vmr->mapping_state = VIRTIO_GPU_MR_UNMAP_COMPLETED;
 
     b = VIRTIO_GPU_BASE(vmr->g);
     b->renderer_blocked--;
@@ -167,6 +173,7 @@ virtio_gpu_virgl_map_resource_blob(VirtIOGPU *g,
     object_initialize_child(OBJECT(g), name, vmr,
                             TYPE_VIRTIO_GPU_VIRGL_HOSTMEM_REGION);
     vmr->g = g;
+    vmr->mapping_state = VIRTIO_GPU_MR_MAPPED;
 
     mr = &vmr->mr;
     memory_region_init_ram_ptr(mr, OBJECT(vmr), "mr", size, data);
@@ -195,7 +202,8 @@ virtio_gpu_virgl_unmap_resource_blob(VirtIOGPU *g,
 
     vmr = to_hostmem_region(res->mr);
 
-    trace_virtio_gpu_cmd_res_unmap_blob(res->base.resource_id, mr, vmr->finish_unmapping);
+    trace_virtio_gpu_cmd_res_unmap_blob(res->base.resource_id, mr,
+                                        vmr->mapping_state);
 
     /*
      * Perform async unmapping in 3 steps:
@@ -206,7 +214,8 @@ virtio_gpu_virgl_unmap_resource_blob(VirtIOGPU *g,
      *    asynchronously by virtio_gpu_virgl_hostmem_region_finalize().
      * 3. Finish the unmapping with final virgl_renderer_resource_unmap().
      */
-    if (vmr->finish_unmapping) {
+    switch (vmr->mapping_state) {
+    case VIRTIO_GPU_MR_UNMAP_COMPLETED:
         res->mr = NULL;
         g_free(vmr);
 
@@ -217,15 +226,22 @@ virtio_gpu_virgl_unmap_resource_blob(VirtIOGPU *g,
                           __func__, strerror(-ret));
             return ret;
         }
-    } else {
-        *cmd_suspended = true;
+        break;
 
+    case VIRTIO_GPU_MR_MAPPED:
         /* render will be unblocked once MR is freed */
         b->renderer_blocked++;
 
+        vmr->mapping_state = VIRTIO_GPU_MR_UNMAP_STARTED;
+
         /* memory region owns self res->mr object and frees it by itself */
         memory_region_del_subregion(&b->hostmem, mr);
         object_unparent(OBJECT(vmr));
+
+        /* Fallthrough */
+    case VIRTIO_GPU_MR_UNMAP_STARTED:
+        *cmd_suspended = true;
+        break;
     }
 
     return 0;
-- 
2.52.0