Hi all, I am working to implement virtgpu S3 function on Xen.
Currently on Xen, if we start a guest who enables virtgpu, and then run "echo mem > /sys/power/state" to suspend guest. And run "sudo xl trigger <guest id> s3resume" to resume guest. We can find that the guest kernel comes back, but the display doesn't. It just shown a black screen. Through reading codes, I founded that when guest was during suspending, it called into Qemu to call virtio_gpu_gl_reset. In virtio_gpu_gl_reset, it destroyed all resources and reset renderer. This made the display gone after guest resumed. I think we should keep resources or prevent they being destroyed when guest is suspending. So, I add a new status named freezing to virtgpu, and add a new ctrl message VIRTIO_GPU_CMD_STATUS_FREEZING to get notification from guest. If freezing is set to true, and then Qemu will realize that guest is suspending, it will not destroy resources and will not reset renderer. If freezing is set to false, Qemu will do its origin actions, and has no other impaction. And now, display can come back and applications can continue their status after guest resumes. Jiqian Chen (1): virtgpu: do not destroy resources when guest suspend hw/display/virtio-gpu-gl.c | 9 ++++++- hw/display/virtio-gpu-virgl.c | 3 +++ hw/display/virtio-gpu.c | 26 +++++++++++++++++++-- include/hw/virtio/virtio-gpu.h | 3 +++ include/standard-headers/linux/virtio_gpu.h | 9 +++++++ 5 files changed, 47 insertions(+), 3 deletions(-) -- 2.34.1
