Hi
On Thu, May 23, 2019 at 3:27 PM Gert Wollny <gert.wol...@collabora.com> wrote:
>
> The default fence poll time of 10ms (100 Hz) is sufficent for normal
> work loads, but if one wants to play games within the virtual machine
> this value might be too high, so make it possible to configure this
> value by using the environment variable QEMU_VIRGL_POLL_FREQ where the
> poll is given in Hz. To acommodate higher poll frequencies also change
> the timer to use micro seconds as base instead of milliseconds.
>
>
This is what VIRGL_RENDERER_THREAD_SYNC helps with. You don't need to
do regular polling, but I think it is currently limited to
Linux/eventfd only.
fwiw, vhost-user-gpu uses it.
> Signed-off-by: Gert Wollny <gert.wol...@collabora.com>
> ---
> hw/display/virtio-gpu-3d.c | 18 ++++++++++++++++--
> include/hw/virtio/virtio-gpu.h | 1 +
> 2 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/hw/display/virtio-gpu-3d.c b/hw/display/virtio-gpu-3d.c
> index 5ee3566ae0..120e593e76 100644
> --- a/hw/display/virtio-gpu-3d.c
> +++ b/hw/display/virtio-gpu-3d.c
> @@ -17,6 +17,7 @@
> #include "trace.h"
> #include "hw/virtio/virtio.h"
> #include "hw/virtio/virtio-gpu.h"
> +#include "qemu/cutils.h"
>
> #ifdef CONFIG_VIRGL
>
> @@ -580,7 +581,8 @@ static void virtio_gpu_fence_poll(void *opaque)
> virgl_renderer_poll();
> virtio_gpu_process_cmdq(g);
> if (!QTAILQ_EMPTY(&g->cmdq) || !QTAILQ_EMPTY(&g->fenceq)) {
> - timer_mod(g->fence_poll, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 1);
> + timer_mod(g->fence_poll, qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) +
> + g->fence_poll_timeout);
> }
> }
>
> @@ -605,13 +607,25 @@ void virtio_gpu_virgl_reset(VirtIOGPU *g)
> int virtio_gpu_virgl_init(VirtIOGPU *g)
> {
> int ret;
> + const char *val;
>
> ret = virgl_renderer_init(g, 0, &virtio_gpu_3d_cbs);
> if (ret != 0) {
> return ret;
> }
>
> - g->fence_poll = timer_new_ms(QEMU_CLOCK_VIRTUAL,
> + g->fence_poll_timeout = 10000; /* default 10 ms */
> + val = getenv("QEMU_VIRGL_POLL_FREQ");
> + if (val) {
> + unsigned long long poll_freq;
> + if (parse_uint_full(val, &poll_freq, 10) || poll_freq > UINT32_MAX) {
> + fprintf(stderr, "VIRGL_POLL_FREQ: Invalid integer `%s'\n", val);
> + exit(1);
> + }
> + g->fence_poll_timeout = 1000000 / (uint32_t)poll_freq;
> + }
> +
> + g->fence_poll = timer_new_us(QEMU_CLOCK_VIRTUAL,
> virtio_gpu_fence_poll, g);
>
> if (virtio_gpu_stats_enabled(g->conf)) {
> diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
> index 60425c5d58..a9e03b25aa 100644
> --- a/include/hw/virtio/virtio-gpu.h
> +++ b/include/hw/virtio/virtio-gpu.h
> @@ -116,6 +116,7 @@ typedef struct VirtIOGPU {
> bool renderer_reset;
> QEMUTimer *fence_poll;
> QEMUTimer *print_stats;
> + uint32_t fence_poll_timeout;
>
> uint32_t inflight;
> struct {
> --
> 2.20.1
>
>
--
Marc-André Lureau
