On Sun, Nov 16, 2025 at 4:58 AM Dmitry Osipenko <[email protected]> wrote: > > Support asynchronous fencing feature of virglrenderer. It allows Qemu to > handle fence as soon as it's signalled instead of periodically polling > the fence status. This feature is required for enabling DRM context > support in Qemu because legacy fencing mode isn't supported for DRM > contexts in virglrenderer. > > Reviewed-by: Akihiko Odaki <[email protected]> > Acked-by: Michael S. Tsirkin <[email protected]> > Tested-by: Alex Bennée <[email protected]> > Reviewed-by: Alex Bennée <[email protected]> > Acked-by: Pierre-Eric Pelloux-Prayer <[email protected]> > Reviewed-by: Yiwei Zhang <[email protected]> > Tested-by: Yiwei Zhang <[email protected]> > Signed-off-by: Dmitry Osipenko <[email protected]> > --- > hw/display/virtio-gpu-gl.c | 5 ++ > hw/display/virtio-gpu-virgl.c | 127 +++++++++++++++++++++++++++++++++ > include/hw/virtio/virtio-gpu.h | 11 +++ > meson.build | 2 + > 4 files changed, 145 insertions(+) > > diff --git a/hw/display/virtio-gpu-gl.c b/hw/display/virtio-gpu-gl.c > index c06a078fb36a..1468c6ed1467 100644 > --- a/hw/display/virtio-gpu-gl.c > +++ b/hw/display/virtio-gpu-gl.c > @@ -169,6 +169,11 @@ static void virtio_gpu_gl_device_unrealize(DeviceState > *qdev) > if (gl->renderer_state >= RS_INITED) { > #if VIRGL_VERSION_MAJOR >= 1 > qemu_bh_delete(gl->cmdq_resume_bh); > + > + if (gl->async_fence_bh) { > + virtio_gpu_virgl_reset_async_fences(g); > + qemu_bh_delete(gl->async_fence_bh); > + } > #endif > if (virtio_gpu_stats_enabled(g->parent_obj.conf)) { > timer_free(gl->print_stats); > diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c > index d9704e3574a0..d6853bfab3cd 100644 > --- a/hw/display/virtio-gpu-virgl.c > +++ b/hw/display/virtio-gpu-virgl.c > @@ -24,6 +24,23 @@ > > #include <virglrenderer.h> > > +/* > + * VIRGL_CHECK_VERSION available since libvirglrenderer 1.0.1 and was fixed > + * in 1.1.0. Undefine bugged version of the macro and provide our own. > + */ > +#if defined(VIRGL_CHECK_VERSION) && \ > + VIRGL_VERSION_MAJOR == 1 && VIRGL_VERSION_MINOR < 1 > +#undef VIRGL_CHECK_VERSION > +#endif > + > +#ifndef VIRGL_CHECK_VERSION > +#define VIRGL_CHECK_VERSION(major, minor, micro) \ > + (VIRGL_VERSION_MAJOR > (major) || \ > + VIRGL_VERSION_MAJOR == (major) && VIRGL_VERSION_MINOR > (minor) || \ > + VIRGL_VERSION_MAJOR == (major) && VIRGL_VERSION_MINOR == (minor) && \ > + VIRGL_VERSION_MICRO >= (micro)) > +#endif > + > struct virtio_gpu_virgl_resource { > struct virtio_gpu_simple_resource base; > MemoryRegion *mr; > @@ -1055,6 +1072,103 @@ static void virgl_write_context_fence(void *opaque, > uint32_t ctx_id, > } > #endif > > +void virtio_gpu_virgl_reset_async_fences(VirtIOGPU *g) > +{ > + struct virtio_gpu_virgl_context_fence *f; > + VirtIOGPUGL *gl = VIRTIO_GPU_GL(g); > + > + while (!QSLIST_EMPTY(&gl->async_fenceq)) { > + f = QSLIST_FIRST(&gl->async_fenceq); > + > + QSLIST_REMOVE_HEAD(&gl->async_fenceq, next); > + > + g_free(f); > + } > +} > + > +#if VIRGL_CHECK_VERSION(1, 1, 2) > +static void virtio_gpu_virgl_async_fence_bh(void *opaque) > +{ > + QSLIST_HEAD(, virtio_gpu_virgl_context_fence) async_fenceq; > + struct virtio_gpu_ctrl_command *cmd, *tmp; > + struct virtio_gpu_virgl_context_fence *f; > + VirtIOGPU *g = opaque; > + VirtIOGPUGL *gl = VIRTIO_GPU_GL(g); > + > + if (gl->renderer_state != RS_INITED) { > + return; > + } > + > + QSLIST_MOVE_ATOMIC(&async_fenceq, &gl->async_fenceq); > + > + while (!QSLIST_EMPTY(&async_fenceq)) { > + f = QSLIST_FIRST(&async_fenceq); > + > + QSLIST_REMOVE_HEAD(&async_fenceq, next); > + > + QTAILQ_FOREACH_SAFE(cmd, &g->fenceq, next, tmp) { > + /* > + * the guest can end up emitting fences out of order > + * so we should check all fenced cmds not just the first one. > + */ > + if (cmd->cmd_hdr.fence_id > f->fence_id) { > + continue; > + } > + if (cmd->cmd_hdr.flags & VIRTIO_GPU_FLAG_INFO_RING_IDX) { > + if (cmd->cmd_hdr.ring_idx != f->ring_idx) { > + continue; > + } > + if (cmd->cmd_hdr.ctx_id != f->ctx_id) { > + continue; > + } > + } > + virtio_gpu_ctrl_response_nodata(g, cmd, > VIRTIO_GPU_RESP_OK_NODATA); > + QTAILQ_REMOVE(&g->fenceq, cmd, next); > + g_free(cmd); > + } > + > + trace_virtio_gpu_fence_resp(f->fence_id); > + g_free(f); > + g->inflight--; > + if (virtio_gpu_stats_enabled(g->parent_obj.conf)) { > + trace_virtio_gpu_dec_inflight_fences(g->inflight); > + } > + } > +} > + > +static void > +virtio_gpu_virgl_push_async_fence(VirtIOGPU *g, uint32_t ctx_id, > + uint32_t ring_idx, uint64_t fence_id) > +{ > + struct virtio_gpu_virgl_context_fence *f; > + VirtIOGPUGL *gl = VIRTIO_GPU_GL(g); > + > + f = g_new(struct virtio_gpu_virgl_context_fence, 1); > + f->ctx_id = ctx_id; > + f->ring_idx = ring_idx; > + f->fence_id = fence_id; > + > + QSLIST_INSERT_HEAD_ATOMIC(&gl->async_fenceq, f, next); > + > + qemu_bh_schedule(gl->async_fence_bh); > +} > + > +static void virgl_write_async_fence(void *opaque, uint32_t fence) > +{ > + VirtIOGPU *g = opaque; > + > + virtio_gpu_virgl_push_async_fence(g, 0, UINT32_MAX, fence); > +} > + > +static void virgl_write_async_context_fence(void *opaque, uint32_t ctx_id, > + uint32_t ring_idx, uint64_t > fence) > +{ > + VirtIOGPU *g = opaque; > + > + virtio_gpu_virgl_push_async_fence(g, ctx_id, ring_idx, fence); > +} > +#endif > + > static virgl_renderer_gl_context > virgl_create_context(void *opaque, int scanout_idx, > struct virgl_renderer_gl_ctx_param *params) > @@ -1154,6 +1268,8 @@ void virtio_gpu_virgl_reset_scanout(VirtIOGPU *g) > void virtio_gpu_virgl_reset(VirtIOGPU *g) > { > virgl_renderer_reset(); > + > + virtio_gpu_virgl_reset_async_fences(g); > } > > int virtio_gpu_virgl_init(VirtIOGPU *g) > @@ -1166,6 +1282,12 @@ int virtio_gpu_virgl_init(VirtIOGPU *g) > if (qemu_egl_display) { > virtio_gpu_3d_cbs.version = 4; > virtio_gpu_3d_cbs.get_egl_display = virgl_get_egl_display; > +#if VIRGL_CHECK_VERSION(1, 1, 2) > + virtio_gpu_3d_cbs.write_fence = virgl_write_async_fence; > + virtio_gpu_3d_cbs.write_context_fence = > virgl_write_async_context_fence; > + flags |= VIRGL_RENDERER_ASYNC_FENCE_CB; > + flags |= VIRGL_RENDERER_THREAD_SYNC; > +#endif > } > #endif > #ifdef VIRGL_RENDERER_D3D11_SHARE_TEXTURE > @@ -1199,6 +1321,11 @@ int virtio_gpu_virgl_init(VirtIOGPU *g) > gl->cmdq_resume_bh = aio_bh_new(qemu_get_aio_context(), > virtio_gpu_virgl_resume_cmdq_bh, > g); > +#if VIRGL_CHECK_VERSION(1, 1, 2) > + gl->async_fence_bh = aio_bh_new(qemu_get_aio_context(), > + virtio_gpu_virgl_async_fence_bh, > + g); > +#endif > #endif > > return 0; > diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h > index 58e0f91fda65..16e9f6914f07 100644 > --- a/include/hw/virtio/virtio-gpu.h > +++ b/include/hw/virtio/virtio-gpu.h > @@ -233,6 +233,13 @@ struct VirtIOGPUClass { > Error **errp); > }; > > +struct virtio_gpu_virgl_context_fence { > + uint32_t ctx_id; > + uint32_t ring_idx; > + uint64_t fence_id; > + QSLIST_ENTRY(virtio_gpu_virgl_context_fence) next; > +}; > + > /* VirtIOGPUGL renderer states */ > typedef enum { > RS_START, /* starting state */ > @@ -250,6 +257,9 @@ struct VirtIOGPUGL { > QEMUTimer *print_stats; > > QEMUBH *cmdq_resume_bh; > + > + QEMUBH *async_fence_bh; > + QSLIST_HEAD(, virtio_gpu_virgl_context_fence) async_fenceq; > }; > > struct VhostUserGPU { > @@ -379,5 +389,6 @@ void virtio_gpu_virgl_reset_scanout(VirtIOGPU *g); > void virtio_gpu_virgl_reset(VirtIOGPU *g); > int virtio_gpu_virgl_init(VirtIOGPU *g); > GArray *virtio_gpu_virgl_get_capsets(VirtIOGPU *g); > +void virtio_gpu_virgl_reset_async_fences(VirtIOGPU *g); > > #endif > diff --git a/meson.build b/meson.build > index b86c9b55562e..2418aaa1a33b 100644 > --- a/meson.build > +++ b/meson.build > @@ -2546,6 +2546,8 @@ config_host_data.set('CONFIG_VNC_JPEG', jpeg.found()) > config_host_data.set('CONFIG_VNC_SASL', sasl.found()) > if virgl.found() > config_host_data.set('VIRGL_VERSION_MAJOR', virgl.version().split('.')[0]) > + config_host_data.set('VIRGL_VERSION_MINOR', virgl.version().split('.')[1]) > + config_host_data.set('VIRGL_VERSION_MICRO', virgl.version().split('.')[2]) > endif > config_host_data.set('CONFIG_VIRTFS', have_virtfs) > config_host_data.set('CONFIG_VTE', vte.found()) > -- > 2.51.1 >
Reviewed-by: Yiwei Zhang <[email protected]>
