File 5d9f454a-x86-EFI-pixel-reserved-0.patch of Package xen.17324

# Commit 521a1445510a30873aec471194045e7f4b5e8d75
# Date 2019-10-10 16:50:50 +0200
# Author Igor Druzhinin <igor.druzhinin@citrix.com>
# Committer Jan Beulich <jbeulich@suse.com>
x86/efi: properly handle 0 in pixel reserved bitmask

In some graphics modes firmware is allowed to return 0 in pixel reserved
bitmask which doesn't go against UEFI Spec 2.8 (12.9 Graphics Output Protocol).

Without this change non-TrueColor modes won't work which will cause
GOP init to fail - observed while trying to boot EFI Xen with Cirrus VGA.

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -528,9 +528,10 @@ static void __init efi_arch_video_init(E
         bpp = set_color(mode_info->PixelInformation.BlueMask, bpp,
                         &vga_console_info.u.vesa_lfb.blue_pos,
                         &vga_console_info.u.vesa_lfb.blue_size);
-        bpp = set_color(mode_info->PixelInformation.ReservedMask, bpp,
-                        &vga_console_info.u.vesa_lfb.rsvd_pos,
-                        &vga_console_info.u.vesa_lfb.rsvd_size);
+        if ( mode_info->PixelInformation.ReservedMask )
+            bpp = set_color(mode_info->PixelInformation.ReservedMask, bpp,
+                            &vga_console_info.u.vesa_lfb.rsvd_pos,
+                            &vga_console_info.u.vesa_lfb.rsvd_size);
         if ( bpp > 0 )
             break;
         /* fall through */