drm/virtio: fix DRM_FORMAT_* handling

Use DRM_FORMAT_HOST_XRGB8888, so we are using the correct format code
on bigendian machines.  Also set the quirk_addfb_prefer_host_byte_order
mode_config bit so drm_mode_addfb() asks for the correct format code.

Both DRM_FORMAT_* and VIRTIO_GPU_FORMAT_* are defined to be little
endian, so using a different mapping on bigendian machines is wrong.
It's there because of broken drm_mode_addfb() behavior.  So with
drm_mode_addfb() being fixed we can fix this too.

While wading through the code I've noticed we have a little issue in
virtio:  We attach a format to the bo when it is created
(DRM_IOCTL_MODE_CREATE_DUMB), not when we map it as framebuffer
(DRM_IOCTL_MODE_ADDFB).  Easy way out:  Support a single format only.
Pick DRM_FORMAT_HOST_XRGB8888, it is the only one actually used in
practice.  Drop unused mappings in virtio_gpu_translate_format().

With this patch applied both ADDFB and ADDFB2 ioctls work correctly in
the virtio-gpu.ko driver on big endian machines.  Without the patch only
ADDFB (which still seems to be used by the majority of userspace) works
correctly.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180921134704.12826-6-kraxel@redhat.com

4 files changed, 13 insertions, 55 deletions

diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c
index 0379d6897659..8f8fed471e34 100644
--- a/drivers/gpu/drm/virtio/virtgpu_display.c
+++ b/drivers/gpu/drm/virtio/virtgpu_display.c
@@ -307,6 +307,10 @@ virtio_gpu_user_framebuffer_create(struct drm_device *dev,
         struct virtio_gpu_framebuffer *virtio_gpu_fb;
         int ret;
 
+        if (mode_cmd->pixel_format != DRM_FORMAT_HOST_XRGB8888 &&
+            mode_cmd->pixel_format != DRM_FORMAT_HOST_ARGB8888)
+                return ERR_PTR(-ENOENT);
+
         /* lookup object associated with res handle */
         obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[0]);
         if (!obj)
@@ -355,6 +359,7 @@ int virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev)
         int i;
 
         drm_mode_config_init(vgdev->ddev);
+        vgdev->ddev->mode_config.quirk_addfb_prefer_host_byte_order = true;
         vgdev->ddev->mode_config.funcs = &virtio_gpu_mode_funcs;
         vgdev->ddev->mode_config.helper_private = &virtio_mode_config_helpers;
 
diff --git a/drivers/gpu/drm/virtio/virtgpu_fb.c b/drivers/gpu/drm/virtio/virtgpu_fb.c
index 3364b0970dd2..e1e41efabec1 100644
--- a/drivers/gpu/drm/virtio/virtgpu_fb.c
+++ b/drivers/gpu/drm/virtio/virtgpu_fb.c
@@ -226,7 +226,7 @@ static int virtio_gpufb_create(struct drm_fb_helper *helper,
         mode_cmd.width = sizes->surface_width;
         mode_cmd.height = sizes->surface_height;
         mode_cmd.pitches[0] = mode_cmd.width * 4;
-        mode_cmd.pixel_format = drm_mode_legacy_fb_format(32, 24);
+        mode_cmd.pixel_format = DRM_FORMAT_HOST_XRGB8888;
 
         format = virtio_gpu_translate_format(mode_cmd.pixel_format);
         if (format == 0)
diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
index 0f2768eacaee..82c817f37cf7 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -90,7 +90,10 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
         uint32_t resid;
         uint32_t format;
 
-        pitch = args->width * ((args->bpp + 1) / 8);
+        if (args->bpp != 32)
+                return -EINVAL;
+
+        pitch = args->width * 4;
         args->size = pitch * args->height;
         args->size = ALIGN(args->size, PAGE_SIZE);
 
@@ -99,7 +102,7 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
         if (ret)
                 goto fail;
 
-        format = virtio_gpu_translate_format(DRM_FORMAT_XRGB8888);
+        format = virtio_gpu_translate_format(DRM_FORMAT_HOST_XRGB8888);
         virtio_gpu_resource_id_get(vgdev, &resid);
         virtio_gpu_cmd_create_resource(vgdev, resid, format,
                                        args->width, args->height);
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 682a977d68c1..a9f4ae7d4483 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -28,22 +28,11 @@
 #include <drm/drm_atomic_helper.h>
 
 static const uint32_t virtio_gpu_formats[] = {
-        DRM_FORMAT_XRGB8888,
-        DRM_FORMAT_ARGB8888,
-        DRM_FORMAT_BGRX8888,
-        DRM_FORMAT_BGRA8888,
-        DRM_FORMAT_RGBX8888,
-        DRM_FORMAT_RGBA8888,
-        DRM_FORMAT_XBGR8888,
-        DRM_FORMAT_ABGR8888,
+        DRM_FORMAT_HOST_XRGB8888,
 };
 
 static const uint32_t virtio_gpu_cursor_formats[] = {
-#ifdef __BIG_ENDIAN
-        DRM_FORMAT_BGRA8888,
-#else
-        DRM_FORMAT_ARGB8888,
-#endif
+        DRM_FORMAT_HOST_ARGB8888,
 };
 
 uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
@@ -51,32 +40,6 @@ uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
         uint32_t format;
 
         switch (drm_fourcc) {
-#ifdef __BIG_ENDIAN
-        case DRM_FORMAT_XRGB8888:
-                format = VIRTIO_GPU_FORMAT_X8R8G8B8_UNORM;
-                break;
-        case DRM_FORMAT_ARGB8888:
-                format = VIRTIO_GPU_FORMAT_A8R8G8B8_UNORM;
-                break;
-        case DRM_FORMAT_BGRX8888:
-                format = VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM;
-                break;
-        case DRM_FORMAT_BGRA8888:
-                format = VIRTIO_GPU_FORMAT_B8G8R8A8_UNORM;
-                break;
-        case DRM_FORMAT_RGBX8888:
-                format = VIRTIO_GPU_FORMAT_R8G8B8X8_UNORM;
-                break;
-        case DRM_FORMAT_RGBA8888:
-                format = VIRTIO_GPU_FORMAT_R8G8B8A8_UNORM;
-                break;
-        case DRM_FORMAT_XBGR8888:
-                format = VIRTIO_GPU_FORMAT_X8B8G8R8_UNORM;
-                break;
-        case DRM_FORMAT_ABGR8888:
-                format = VIRTIO_GPU_FORMAT_A8B8G8R8_UNORM;
-                break;
-#else
         case DRM_FORMAT_XRGB8888:
                 format = VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM;
                 break;
@@ -89,19 +52,6 @@ uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
         case DRM_FORMAT_BGRA8888:
                 format = VIRTIO_GPU_FORMAT_A8R8G8B8_UNORM;
                 break;
-        case DRM_FORMAT_RGBX8888:
-                format = VIRTIO_GPU_FORMAT_X8B8G8R8_UNORM;
-                break;
-        case DRM_FORMAT_RGBA8888:
-                format = VIRTIO_GPU_FORMAT_A8B8G8R8_UNORM;
-                break;
-        case DRM_FORMAT_XBGR8888:
-                format = VIRTIO_GPU_FORMAT_R8G8B8X8_UNORM;
-                break;
-        case DRM_FORMAT_ABGR8888:
-                format = VIRTIO_GPU_FORMAT_R8G8B8A8_UNORM;
-                break;
-#endif
         default:
                 /*
                  * This should not happen, we handle everything listed