Am Donnerstag, den 23.05.2019, 16:37 +0200 schrieb Marc-André Lureau: > Hi > > On Thu, May 23, 2019 at 4:17 PM Gert Wollny < > gert.wol...@collabora.com> wrote: > > Am Donnerstag, den 23.05.2019, 16:01 +0200 schrieb Marc-André > > Lureau: > > > 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. > > > > As far as I can see only vtest uses this, not qemu. > > I don't think there is anything preventing qemu from using it, except > the portability which should be taken care more carefully.
But to actually use it would need quite some work, wouldn't it? (I'm thinking of your series: http://qemu.11.n7.nabble.com/PATCH-00-18-virgl-use-a-seperate-rendering-thread-tt429557.html ) That's why I though that being able to configure the polling frequency might be an easy way to give some performance boost. > > > > fwiw, vhost-user-gpu uses it. > > > > Yeah, I tested it on Intel, but AFAICS this hasn't landed yet, no? > > OTOH > > the drm calls were only implemented for Intel, and I have no idea > > how > > to implement this for other hardware, like e.g. radeonsi, or even > > the > > Nvidia blob ... > > I just sent v8 for review today: > https://patchew.org/QEMU/20190523132035.20559-1-marcandre.lur...@redhat.com/ > > The DRM bits were replaced by GBM usage, which will give some > portability. That's great, I'll give it a spin in the next view days. Best, Gert > > > > > > > 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 > > > > > > > > > >
