On 11/09/2016, 09:01 AM, Gerd Hoffmann wrote: > On Di, 2016-11-08 at 22:37 +0200, Michael S. Tsirkin wrote: >> On Mon, Nov 07, 2016 at 09:43:24AM +0100, Jiri Slaby wrote: >>> Hi, >>> >>> I can relatively easily reproduce this bug: > > How? Run dmesg -w in the qemu window (virtio_gpu) to see a lot of output. Run pps [1] without exit(0); on e.g. serial console. Wait a bit. The lot of output causes the BUG. [1] https://github.com/jirislaby/collected_sources/blob/master/pps.c >>> BUG: 'list_empty(&vgdev->free_vbufs)' is true! > >> The following might be helpful for debugging - if kernel still will >> not stop panicing, we are looking at some kind >> of memory corruption. > > Looking carefully through the code I think it isn't impossible to > trigger this, but you need for that: > > (1) command queue full (quite possible), > (2) cursor queue full too (unlikely), and > (3) multiple threads trying to submit commands and waiting for free > space in the command queue (possible with virgl enabled). I use -vga virtio with no -display option, so no virtgl, I suppose: [drm] virgl 3d acceleration not available > Do things improve if you allocate some extra bufs? > > int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev) > { > struct virtio_gpu_vbuffer *vbuf; > - int i, size, count = 0; > + int i, size, count = 16; This seems to help. thanks, -- js suse labs _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
