virtio-gpu: Support suspension of commands processing

Check whether command processing has been finished; otherwise, stop
processing commands and retry the command again next time. This allows
us to support asynchronous execution of non-fenced commands needed for
unmapping host blobs safely.

Suggested-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Message-Id: <20241024210311.118220-11-dmitry.osipenko@collabora.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

diff --git a/hw/display/trace-events b/hw/display/trace-events
index e212710284ae7c5524aa12deb06556fc0c5a2df0..d26d663f9638beba979f12cd532045b61078f108 100644 (file)
--- a/hw/display/trace-events
+++ b/hw/display/trace-events
@@ -55,6 +55,7 @@ virtio_gpu_fence_ctrl(uint64_t fence, uint32_t type) "fence 0x%" PRIx64 ", type
 virtio_gpu_fence_resp(uint64_t fence) "fence 0x%" PRIx64
 virtio_gpu_inc_inflight_fences(uint32_t inflight) "in-flight+ %u"
 virtio_gpu_dec_inflight_fences(uint32_t inflight) "in-flight- %u"
+virtio_gpu_cmd_suspended(uint32_t cmd) "cmd 0x%x"
 
 # qxl.c
 disable qxl_io_write_vga(int qid, const char *mode, uint32_t addr, uint32_t val) "%d %s addr=%u val=%u"

diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 3d9679c1ef9838eda77da85a467b03175a146568..180d882f0a49bf40451fe980bc1b5e2b29f2fa98 100644 (file)
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -1034,6 +1034,12 @@ void virtio_gpu_process_cmdq(VirtIOGPU *g)
         /* process command */
         vgc->process_cmd(g, cmd);
 
+        /* command suspended */
+        if (!cmd->finished && !(cmd->cmd_hdr.flags & VIRTIO_GPU_FLAG_FENCE)) {
+            trace_virtio_gpu_cmd_suspended(cmd->cmd_hdr.type);
+            break;
+        }
+
         QTAILQ_REMOVE(&g->cmdq, cmd, next);
         if (virtio_gpu_stats_enabled(g->parent_obj.conf)) {
             g->stats.requests++;