[ Upstream commit 71d3f6ef7f5af38dea2975ec5715c88bae92e92d ]

virtio uses normal ram as backing storage for the framebuffer, so we
should assign the address to new screen_buffer (added by commit
17a7b0b4d9749f80d365d7baff5dec2f54b0e992) instead of screen_base.

Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- add missing header for virtgpu_fb.c

Cc: David Airlie <airlied@linux.ie>
Cc: Gerd Hoffmann <kraxel@redhat.com>

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

virtio_gpu_alloc_object() returns an error pointer, it never returns
NULL.

Fixes: dc5698e80cf7 ('Add virtio gpu driver.')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

This patch adds a kms driver for the virtio gpu.  The xorg modesetting
driver can handle the device just fine, the framebuffer for fbcon is
there too.

Qemu patches for the host side are under review currently.

The pci version of the device comes in two variants: with and without
vga compatibility.  The former has a extra memory bar for the vga
framebuffer, the later is a pure virtio device.  The only concern for
this driver is that in the virtio-vga case we have to kick out the
firmware framebuffer.

Initial revision has only 2d support, 3d (virgl) support requires
some more work on the qemu side and will be added later.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>