Hi Paul,

Thanks for verifying that linux-nvidia kernel, but for the future, you
don't need to worry about verifying each and every kernel series. These
days, the kernel team maintains over 100 kernel variants, and it is
simply impossible to check them all.

We just check the primary ones, e.g. 5.19 in kinetic, and then when they
are made into their specific derivative kernels, e.g. 5.19 linux-nvidia,
they contain all the patches from the primary kernel, plus some specific
patches to enable whatever hardware the derivative kernel is for.

So, don't worry if there are any more from other odd kernel
combinations, I will let you know if we need to do any more testing.

In other news, looking at https://kernel.ubuntu.com/, we should be on
track for a release to -updates early next week, so look forward to that
and getting this bug fixed for everyone.

Thanks,
Matthew

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/2007001

Title:
  vmwgfx fails to reserve graphics buffer on aarch64 leading to blank
  display

Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Kinetic:
  Fix Committed

Bug description:
  BugLink: https://bugs.launchpad.net/bugs/2007001

  [Impact]

  Numerous VMWare users have reported that vmwgfx cannot reserve the
  memory region for the graphics framebuffer, leading their VMs to have
  blank screens.

  They see the following in dmesg:

  [ 11.135360] vmwgfx 0000:00:0f.0: BAR 2: can't reserve [mem 
0x70000000-0x77ffffff 64bit pref]
  [ 11.135366] vmwgfx: probe of 0000:00:0f.0 failed with error -16

  And a cat /proc/iomem shows this:

  50000000-7fffffff : PCI Bus 0000:00
    70000000-77ffffff : 0000:00:0f.0
      70000000-702fffff : BOOTFB

  The kernel has failed to release this memory region for vmwgfx to
  occupy.

  Most affected users are on aarch64, with the host being Apple silicon
  systems.

  [Fix]

  The regression was introduced by the below commit in
  5.19.0-30-generic:

  commit 5e01376124309b4dbd30d413f43c0d9c2f60edea
  Author: Thomas Zimmermann <tzimmerm...@suse.de>
  Date: Mon Jul 18 09:23:18 2022 +0200
  Subject: video/aperture: Disable and unregister sysfb devices via aperture 
helpers
  Link: 
https://github.com/torvalds/linux/commit/5e01376124309b4dbd30d413f43c0d9c2f60edea

  This commit was part of a larger refactoring of the video subsystem,
  and requires the entire series to function correctly. You can review
  the whole series below:

  https://patchwork.freedesktop.org/series/106040/

  The patch series also requires quite a few additional fixups to fix
  bugs introduced by the series, making the size about 15 commits in
  total. The contents of the series don't really fix any bugs, and their
  purpose is to refactor the code for future changes to the fbdev
  subsystem, and really aren't appropriate to be backported to a stable
  kernel series.

  "video/aperture: Disable and unregister sysfb devices via aperture
  helpers" seems to have been selected for -stable by mistake by its
  fixes: tag, and was pulled into upstream stable by a robot with little
  human review.

  The best course of action is to revert. No action needed for Lunar, as
  the entire series is present in that release.

  [Testcase]

  This bug affects users running Ubuntu in VMWare VMs, notably on
  aarch64 devices, like modern Apple computers.

  Start a Kinetic or Jammy-HWE Server or Desktop VM in VMWare Fusion on
  Apple silicon, and see if the display comes up or not.

  Affected users will see a blank screen.

  There is a test kernel available in the following ppa:

  https://launchpad.net/~mruffell/+archive/ubuntu/lp2007001-test

  If you install the test kernel and reboot, you will be able to see the
  screen on your VM like normal.

  [Where problems could occur]

  This commit changes when the sysfb is disabled and memory region for
  the graphics framebuffer is released to the proper device driver.

  If a regression were to occur, then graphics drivers may fail to
  reserve the framebuffer memory, and fail to start, leaving users with
  a blank screen.

  There are no workarounds, other than booting a previous kernel.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2007001/+subscriptions


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