Hi, Commit ccf953d8f3d6 ("fb_defio: Remove custom address_space_operations") seems to be breaking Hyper-V framebuffer (drivers/video/fbdev/hyperv_fb.c) driver for me: Hyper-V guest boots well and plymouth even works but when I try starting Gnome, virtual screen just goes black. Reverting the above mentioned commit on top of 5.13-rc4 saves the day. The behavior is 100% reproducible. I'm using Gen2 guest runing on Hyper-V 2019. It was also reported that Gen1 guests are equally broken. Is this something known? -- Vitaly