Use EGL_LINUX_DMA_BUF_EXT to create GBM bo EGLImages

Xwayland was passing GBM bos directly to
eglCreateImageKHR using the EGL_NATIVE_PIXMAP_KHR
target. Given the EGL GBM platform spec claims it
is invalid to create a EGLSurface from a native
pixmap on the GBM platform, implying there is no
mapping between GBM objects and EGL's concept of
native pixmaps, this seems a bit questionable.

This change modifies the bo import function to
extract all the required data from the bo and then
imports it as a dma-buf instead when the dma-buf +
modifiers path is available.

Signed-off-by: James Jones <jajones@nvidia.com>
Reviewed-by: Simon Ser <contact@emersion.fr>

configure.ac

@@ -2050,6 +2050,10 @@ if test "x$GLAMOR" = xyes; then
 		PKG_CHECK_EXISTS(gbm >= 17.1.0,
 				 [AC_DEFINE(GBM_BO_WITH_MODIFIERS, 1, [Have gbm_bo_create_with_modifiers])],
 				 [])
+		dnl 21.1.0 is required for gbm_bo_get_fd_for_plane
+		PKG_CHECK_EXISTS(gbm >= 21.1.0,
+				 [AC_DEFINE(GBM_BO_FD_FOR_PLANE, 1, [Have gbm_bo_get_fd_for_plane])],
+				 [])
 	else
 		if test "x$XORG" = xyes; then
 			AC_MSG_ERROR([Glamor for Xorg requires $LIBGBM])

hw/xwayland/xwayland-glamor-gbm.c

@@ -120,6 +120,55 @@ xwl_glamor_gbm_create_pixmap_for_bo(ScreenPtr screen, struct gbm_bo *bo,
     PixmapPtr pixmap;
     struct xwl_pixmap *xwl_pixmap;
     struct xwl_screen *xwl_screen = xwl_screen_get(screen);
+#ifdef GBM_BO_FD_FOR_PLANE
+    struct xwl_gbm_private *xwl_gbm = xwl_gbm_get(xwl_screen);
+    uint64_t modifier = gbm_bo_get_modifier(bo);
+    const int num_planes = gbm_bo_get_plane_count(bo);
+    int fds[GBM_MAX_PLANES];
+    int plane;
+    int attr_num = 0;
+    EGLint img_attrs[64] = {0};
+    enum PlaneAttrs {
+        PLANE_FD,
+        PLANE_OFFSET,
+        PLANE_PITCH,
+        PLANE_MODIFIER_LO,
+        PLANE_MODIFIER_HI,
+        NUM_PLANE_ATTRS
+    };
+    static const EGLint planeAttrs[][NUM_PLANE_ATTRS] = {
+        {
+            EGL_DMA_BUF_PLANE0_FD_EXT,
+            EGL_DMA_BUF_PLANE0_OFFSET_EXT,
+            EGL_DMA_BUF_PLANE0_PITCH_EXT,
+            EGL_DMA_BUF_PLANE0_MODIFIER_LO_EXT,
+            EGL_DMA_BUF_PLANE0_MODIFIER_HI_EXT,
+        },
+        {
+            EGL_DMA_BUF_PLANE1_FD_EXT,
+            EGL_DMA_BUF_PLANE1_OFFSET_EXT,
+            EGL_DMA_BUF_PLANE1_PITCH_EXT,
+            EGL_DMA_BUF_PLANE1_MODIFIER_LO_EXT,
+            EGL_DMA_BUF_PLANE1_MODIFIER_HI_EXT,
+        },
+        {
+            EGL_DMA_BUF_PLANE2_FD_EXT,
+            EGL_DMA_BUF_PLANE2_OFFSET_EXT,
+            EGL_DMA_BUF_PLANE2_PITCH_EXT,
+            EGL_DMA_BUF_PLANE2_MODIFIER_LO_EXT,
+            EGL_DMA_BUF_PLANE2_MODIFIER_HI_EXT,
+        },
+        {
+            EGL_DMA_BUF_PLANE3_FD_EXT,
+            EGL_DMA_BUF_PLANE3_OFFSET_EXT,
+            EGL_DMA_BUF_PLANE3_PITCH_EXT,
+            EGL_DMA_BUF_PLANE3_MODIFIER_LO_EXT,
+            EGL_DMA_BUF_PLANE3_MODIFIER_HI_EXT,
+        },
+    };
+
+    for (plane = 0; plane < num_planes; plane++) fds[plane] = -1;
+#endif
 
     xwl_pixmap = calloc(1, sizeof(*xwl_pixmap));
     if (xwl_pixmap == NULL)
@@ -138,10 +187,57 @@ xwl_glamor_gbm_create_pixmap_for_bo(ScreenPtr screen, struct gbm_bo *bo,
     xwl_glamor_egl_make_current(xwl_screen);
     xwl_pixmap->bo = bo;
     xwl_pixmap->buffer = NULL;
-    xwl_pixmap->image = eglCreateImageKHR(xwl_screen->egl_display,
+
-                                          xwl_screen->egl_context,
+#ifdef GBM_BO_FD_FOR_PLANE
-                                          EGL_NATIVE_PIXMAP_KHR,
+    if (xwl_gbm->dmabuf_capable) {
-                                          xwl_pixmap->bo, NULL);
+#define ADD_ATTR(attrs, num, attr)                                      \
+        do {                                                            \
+            assert(((num) + 1) < (sizeof(attrs) / sizeof((attrs)[0]))); \
+            (attrs)[(num)++] = (attr);                                  \
+        } while (0)
+        ADD_ATTR(img_attrs, attr_num, EGL_WIDTH);
+        ADD_ATTR(img_attrs, attr_num, gbm_bo_get_width(bo));
+        ADD_ATTR(img_attrs, attr_num, EGL_HEIGHT);
+        ADD_ATTR(img_attrs, attr_num, gbm_bo_get_height(bo));
+        ADD_ATTR(img_attrs, attr_num, EGL_LINUX_DRM_FOURCC_EXT);
+        ADD_ATTR(img_attrs, attr_num, gbm_bo_get_format(bo));
+
+        for (plane = 0; plane < num_planes; plane++) {
+            fds[plane] = gbm_bo_get_fd_for_plane(bo, plane);
+            ADD_ATTR(img_attrs, attr_num, planeAttrs[plane][PLANE_FD]);
+            ADD_ATTR(img_attrs, attr_num, fds[plane]);
+            ADD_ATTR(img_attrs, attr_num, planeAttrs[plane][PLANE_OFFSET]);
+            ADD_ATTR(img_attrs, attr_num, gbm_bo_get_offset(bo, plane));
+            ADD_ATTR(img_attrs, attr_num, planeAttrs[plane][PLANE_PITCH]);
+            ADD_ATTR(img_attrs, attr_num, gbm_bo_get_stride_for_plane(bo, plane));
+            ADD_ATTR(img_attrs, attr_num, planeAttrs[plane][PLANE_MODIFIER_LO]);
+            ADD_ATTR(img_attrs, attr_num, (uint32_t)(modifier & 0xFFFFFFFFULL));
+            ADD_ATTR(img_attrs, attr_num, planeAttrs[plane][PLANE_MODIFIER_HI]);
+            ADD_ATTR(img_attrs, attr_num, (uint32_t)(modifier >> 32ULL));
+        }
+        ADD_ATTR(img_attrs, attr_num, EGL_NONE);
+#undef ADD_ATTR
+
+        xwl_pixmap->image = eglCreateImageKHR(xwl_screen->egl_display,
+                                              EGL_NO_CONTEXT,
+                                              EGL_LINUX_DMA_BUF_EXT,
+                                              NULL,
+                                              img_attrs);
+
+        for (plane = 0; plane < num_planes; plane++) {
+            close(fds[plane]);
+            fds[plane] = -1;
+        }
+    }
+    else
+#endif
+    {
+        xwl_pixmap->image = eglCreateImageKHR(xwl_screen->egl_display,
+                                              xwl_screen->egl_context,
+                                              EGL_NATIVE_PIXMAP_KHR,
+                                              xwl_pixmap->bo, NULL);
+    }
+
     if (xwl_pixmap->image == EGL_NO_IMAGE_KHR)
       goto error;
 

include/dix-config.h.in

@@ -473,6 +473,9 @@
 /* GBM has modifiers support */
 #undef GBM_BO_WITH_MODIFIERS
 
+/* GBM has gbm_bo_get_fd_for_plane function */
+#undef GBM_BO_FD_FOR_PLANE
+
 /* Glamor can use eglQueryDmaBuf* functions */
 #undef GLAMOR_HAS_EGL_QUERY_DMABUF
 

include/meson.build

@@ -113,6 +113,8 @@ conf_data.set('GLAMOR_HAS_GBM_LINEAR',
               build_glamor and gbm_dep.found() and gbm_dep.version().version_compare('>= 10.6') ? '1' : false)
 conf_data.set('GBM_BO_WITH_MODIFIERS',
               build_glamor and gbm_dep.found() and gbm_dep.version().version_compare('>= 17.1') ? '1' : false)
+conf_data.set('GBM_BO_FD_FOR_PLANE',
+              build_glamor and gbm_dep.found() and gbm_dep.version().version_compare('>= 21.1') ? '1' : false)
 
 conf_data.set_quoted('SERVER_MISC_CONFIG_PATH', serverconfigdir)
 conf_data.set_quoted('PROJECTROOT', get_option('prefix'))