Linux guest OGL regression in 5.2.8 (LKG 5.1.30)

[arQon]

After updating the host from 5.1.30 to 5.2.8, an Ubuntu 16.04 guest that has 3D enabled continued to work fine for a couple of hours, until I got round to updating the GAs as well. At that point, restarting the guest arrived at the desktop but immediately started consuming memory at an impressive rate, killing the X session (as you'd expect).

The leak can be traced to the Compton compositor, which when started from a terminal instead of automatically is spitting out thousands of these messages:

glx_bind_pixmap(32): Couldn't find FBConfig with requested depth. win_paint_shadow(0x0320002d): Missing painting data. This is a bad sign.

glxinfo looks good, containing the one visual I'd expect to see:

1 GLX Visuals

visual x bf lv rg d st colorbuffer sr ax dp st accumbuffer ms cav

id dep cl sp sz l ci b ro r g b a F gb bf th cl r g b a ns b eat

---

0x021 24 tc 0 32 0 r y y 8 8 8 8 . . 0 24 8 16 16 16 16 0 0 None

1 GLXFBConfigs:

visual x bf lv rg d st colorbuffer sr ax dp st accumbuffer ms cav

id dep cl sp sz l ci b ro r g b a F gb bf th cl r g b a ns b eat

---

0x021 24 tc 0 32 0 r y . 8 8 8 8 . . 0 24 8 0 0 0 0 1 1 None

I can try bisecting to narrow down the breaking revision, but it'll take a while.