Lucas Amaral <[email protected]> writes:
> Venus (virtio-gpu Vulkan context) currently requires an OpenGL
> display backend due to build-time and runtime coupling. On macOS,
> no OpenGL display backend exists.
>
> Remove the opengl.found() build requirement for the virtio-gpu-gl
> module; virglrenderer provides Venus independently of OpenGL.
>
> Gate GL-specific code paths behind CONFIG_OPENGL and display_opengl:
> - Only advertise VIRGL/VIRGL2 capsets when display_opengl is set
> - Only pass VIRGL_RENDERER_NO_VIRGL when !display_opengl with Venus
> - Null out GL context callbacks when no GL display is available
> - Route 2D display commands to the software renderer (pixman) when
> Venus runs without GL (venus no-GL mode)
> - Allow Venus to bypass the OpenGL display check at device realize
>
> Signed-off-by: Lucas Amaral <[email protected]>
<snip>
> @@ -157,7 +158,18 @@ virtio_gpu_get_flags(void *opaque)
> VirtIOGPUBase *g = opaque;
> int flags = GRAPHIC_FLAGS_NONE;
>
> - if (virtio_gpu_virgl_enabled(g->conf)) {
> + if (virtio_gpu_venus_enabled(g->conf)) {
> + /* TODO: set GRAPHIC_FLAGS_VK for direct Vulkan scanout */
> + }
> +
> + /*
> + * TODO: virtio_gpu_virgl_enabled() checks VIRTIO_GPU_FLAG_VIRGL_ENABLED
> + * which is set for both OpenGL (VIRGL) and Vulkan (Venus) backends.
> + * This condition should ideally use a dedicated OpenGL-only
> flag.
Isn't this entirely in QEMU's control? The Venus flag is checked when
needed and set by:
DEFINE_PROP_BIT("venus", VirtIOGPU, parent_obj.conf.flags,
VIRTIO_GPU_FLAG_VENUS_ENABLED, false),
So do we just need to define:
DEFINE_PROP_BIT("virgl", VirtIOGPU, parent_obj.conf.flags,
VIRTIO_GPU_FLAG_VIRGL_ENABLED, true),
and allow the user to squash it and drop the:
g->parent_obj.conf.flags |= (1 << VIRTIO_GPU_FLAG_VIRGL_ENABLED);
I guess we need to drop the prop bit definition on platforms that can't
support OpenGL?
> For
> + * now, display_opengl correctly gates GL scanout since Venus leaves it
> + * at 0.
> + */
> + if (virtio_gpu_virgl_enabled(g->conf) && display_opengl) {
> flags |= GRAPHIC_FLAGS_GL;
> }
>
> @@ -273,6 +285,7 @@ virtio_gpu_base_get_features(VirtIODevice *vdev, uint64_t
> features,
> }
> if (virtio_gpu_blob_enabled(g->conf)) {
> features |= (1 << VIRTIO_GPU_F_RESOURCE_BLOB);
> + features |= (1 << VIRTIO_GPU_F_BLOB_ALIGNMENT);
> }
> if (virtio_gpu_context_init_enabled(g->conf)) {
> features |= (1 << VIRTIO_GPU_F_CONTEXT_INIT);
> diff --git a/hw/display/virtio-gpu-gl.c b/hw/display/virtio-gpu-gl.c
> index 2b7a41c4..1a95e6a7 100644
> --- a/hw/display/virtio-gpu-gl.c
> +++ b/hw/display/virtio-gpu-gl.c
> @@ -124,7 +124,9 @@ static void virtio_gpu_gl_device_realize(DeviceState
> *qdev, Error **errp)
> return;
> }
>
> - if (!display_opengl) {
> + if (virtio_gpu_venus_enabled(g->parent_obj.conf)) {
> + /* Venus uses Vulkan in the render server, no GL needed */
> + } else if (!display_opengl) {
> error_setg(errp,
> "The display backend does not have OpenGL support
> enabled");
> error_append_hint(errp,
> @@ -245,4 +247,6 @@ static void virtio_register_types(void)
> type_init(virtio_register_types)
>
> module_dep("hw-display-virtio-gpu");
> +#ifdef CONFIG_OPENGL
> module_dep("ui-opengl");
> +#endif
> diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
> index b7a2d160..2f9700e0 100644
> --- a/hw/display/virtio-gpu-virgl.c
> +++ b/hw/display/virtio-gpu-virgl.c
> @@ -19,8 +19,10 @@
> #include "hw/virtio/virtio-gpu.h"
> #include "hw/virtio/virtio-gpu-bswap.h"
> #include "hw/virtio/virtio-gpu-pixman.h"
> -
> +#include "system/system.h"
> +#ifdef CONFIG_OPENGL
> #include "ui/egl-helpers.h"
> +#endif
>
> #include <virglrenderer.h>
>
> @@ -50,6 +52,16 @@ struct virtio_gpu_virgl_resource {
> void *map_fixed;
> };
>
> +/*
> + * Venus no-GL mode: Venus is enabled but no OpenGL display is available.
> + * Display commands use software (pixman) rendering; Venus/3D commands
> + * go through the virglrenderer render server.
> + */
> +static bool virtio_gpu_venus_nogl(VirtIOGPU *g)
> +{
> + return virtio_gpu_venus_enabled(g->parent_obj.conf) && !display_opengl;
> +}
> +
> static struct virtio_gpu_virgl_resource *
> virtio_gpu_virgl_find_resource(VirtIOGPU *g, uint32_t resource_id)
> {
> @@ -63,7 +75,7 @@ virtio_gpu_virgl_find_resource(VirtIOGPU *g, uint32_t
> resource_id)
> return container_of(res, struct virtio_gpu_virgl_resource, base);
> }
>
> -#if VIRGL_RENDERER_CALLBACKS_VERSION >= 4
> +#if VIRGL_RENDERER_CALLBACKS_VERSION >= 4 && defined(CONFIG_OPENGL)
> static void *
> virgl_get_egl_display(G_GNUC_UNUSED void *cookie)
> {
> @@ -1032,6 +1044,45 @@ void virtio_gpu_virgl_process_cmd(VirtIOGPU *g,
>
> VIRTIO_GPU_FILL_CMD(cmd->cmd_hdr);
>
> + /*
> + * Venus no-GL mode: route 2D display commands to the base software
> + * renderer (pixman). The guest kernel always uses 2D commands for
> + * display framebuffers even with VIRGL enabled; Venus/3D commands
> + * go through the virglrenderer render server as usual.
> + */
> + if (virtio_gpu_venus_nogl(g)) {
> + switch (cmd->cmd_hdr.type) {
> + case VIRTIO_GPU_CMD_RESOURCE_CREATE_2D:
> + case VIRTIO_GPU_CMD_SET_SCANOUT:
> + case VIRTIO_GPU_CMD_RESOURCE_FLUSH:
> + case VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D:
> + case VIRTIO_GPU_CMD_GET_DISPLAY_INFO:
> + case VIRTIO_GPU_CMD_GET_EDID:
> + virtio_gpu_simple_process_cmd(g, cmd);
> + return;
> + case VIRTIO_GPU_CMD_RESOURCE_UNREF:
> + case VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING:
> + case VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING: {
> + /*
> + * Both 2D (simple) and blob (virgl) resources share g->reslist.
> + * Check if virglrenderer owns the resource to pick
> + * the right handler.
> + */
> + struct virtio_gpu_resource_unref hdr;
> + struct virgl_renderer_resource_info info;
> + VIRTIO_GPU_FILL_CMD(hdr);
> + if (virgl_renderer_resource_get_info(hdr.resource_id, &info)) {
> + /* Not in virglrenderer — it's a 2D software resource */
> + virtio_gpu_simple_process_cmd(g, cmd);
> + return;
> + }
> + break; /* virglrenderer owns it — fall through */
> + }
> + default:
> + break;
> + }
> + }
> +
> virgl_renderer_force_ctx_0();
> switch (cmd->cmd_hdr.type) {
> case VIRTIO_GPU_CMD_CTX_CREATE:
> @@ -1433,6 +1484,7 @@ static int virtio_gpu_virgl_init(VirtIOGPU *g)
> uint32_t flags = 0;
> VirtIOGPUGL *gl = VIRTIO_GPU_GL(g);
>
> +#ifdef CONFIG_OPENGL
> #if VIRGL_RENDERER_CALLBACKS_VERSION >= 4
> if (qemu_egl_display) {
> virtio_gpu_3d_cbs.version = 4;
> @@ -1450,9 +1502,14 @@ static int virtio_gpu_virgl_init(VirtIOGPU *g)
> flags |= VIRGL_RENDERER_D3D11_SHARE_TEXTURE;
> }
> #endif
> +#endif /* CONFIG_OPENGL */
> #if VIRGL_VERSION_MAJOR >= 1
> if (virtio_gpu_venus_enabled(g->parent_obj.conf)) {
> - flags |= VIRGL_RENDERER_VENUS | VIRGL_RENDERER_RENDER_SERVER;
> + flags |= VIRGL_RENDERER_VENUS
> + | VIRGL_RENDERER_RENDER_SERVER;
> + if (!display_opengl) {
> + flags |= VIRGL_RENDERER_NO_VIRGL;
> + }
> }
> if (virtio_gpu_drm_enabled(g->parent_obj.conf)) {
> flags |= VIRGL_RENDERER_DRM;
> @@ -1475,6 +1532,12 @@ static int virtio_gpu_virgl_init(VirtIOGPU *g)
> }
> #endif
>
> + if (!display_opengl) {
> + virtio_gpu_3d_cbs.create_gl_context = NULL;
> + virtio_gpu_3d_cbs.destroy_gl_context = NULL;
> + virtio_gpu_3d_cbs.make_current = NULL;
> + }
> +
> ret = virgl_renderer_init(g, flags, &virtio_gpu_3d_cbs);
> if (ret != 0) {
> error_report("virgl could not be initialized: %d", ret);
> @@ -1546,14 +1609,16 @@ GArray *virtio_gpu_virgl_get_capsets(VirtIOGPU *g)
>
> capset_ids = g_array_new(false, false, sizeof(uint32_t));
>
> - /* VIRGL is always supported. */
> - virtio_gpu_virgl_add_capset(capset_ids, VIRTIO_GPU_CAPSET_VIRGL);
> + /* OpenGL: VIRGL/VIRGL2 require a GL display backend */
> + if (display_opengl) {
> + virtio_gpu_virgl_add_capset(capset_ids, VIRTIO_GPU_CAPSET_VIRGL);
>
> - virgl_renderer_get_cap_set(VIRTIO_GPU_CAPSET_VIRGL2,
> - &capset_max_ver,
> - &capset_max_size);
> - if (capset_max_ver) {
> - virtio_gpu_virgl_add_capset(capset_ids, VIRTIO_GPU_CAPSET_VIRGL2);
> + virgl_renderer_get_cap_set(VIRTIO_GPU_CAPSET_VIRGL2,
> + &capset_max_ver,
> + &capset_max_size);
> + if (capset_max_ver) {
> + virtio_gpu_virgl_add_capset(capset_ids,
> VIRTIO_GPU_CAPSET_VIRGL2);
> + }
> }
>
> if (virtio_gpu_venus_enabled(g->parent_obj.conf)) {
--
Alex Bennée
Virtualisation Tech Lead @ Linaro
