[Bug 1826453] Please test proposed package

[Brian Murray]

Hello Dexuan, or anyone else affected,

Accepted grub2-signed into xenial-proposed. The package will build now
and be available at
https://launchpad.net/ubuntu/+source/grub2-signed/1.66.22 in a few
hours, and then in the -proposed repository.

Please help us by testing this new package.  See
https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how
to enable and use -proposed.  Your feedback will aid us getting this
update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug,
mentioning the version of the package you tested and change the tag from
verification-needed-xenial to verification-done-xenial. If it does not
fix the bug for you, please add a comment stating that, and change the
tag to verification-failed-xenial. In either case, without details of
your testing we will not be able to proceed.

Further information regarding the verification process can be found at
https://wiki.ubuntu.com/QATeam/PerformingSRUVerification .  Thank you in
advance for helping!

N.B. The updated package will be released to -updates after the bug(s)
fixed by this package have been verified and the package has been in
-proposed for a minimum of 7 days.

** Also affects: grub2-signed (Ubuntu)
   Importance: Undecided
       Status: New

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https://bugs.launchpad.net/bugs/1826453

Title:
  Grub2 Booting in blind mode due to "invalid video mode specification
  `text'"

Status in grub2 package in Ubuntu:
  Fix Released
Status in grub2-signed package in Ubuntu:
  New
Status in grub2 source package in Trusty:
  New
Status in grub2-signed source package in Trusty:
  New
Status in grub2 source package in Xenial:
  Fix Committed
Status in grub2-signed source package in Xenial:
  New

Bug description:
  [Impact]
  UEFI users booting VMs on Hyper-V

  [Test case]
  1) Install Ubuntu 16.04 in a Gen2 VM on Hyper-V (Windows)
  2) After install; edit /etc/default/grub to add:
  GRUB_GFXPAYLOAD_LINUX="text"
  3) Run 'sudo update-grub'
  4) Reboot

  Verify whether the system writes an error/warning on console during
  boot (this shows up and disappears quickly, one must watch the console
  attentively):

  error: invalid video mode specification `text'.
  Booting in blind mode

  
  [Regression potential]
  There is minimal risk of regression; this is a patch that has been succesfully used in other releases to address the same issue (see bug 1711452). It only affects graphical payload selection in grub to avoid a value that is clearly invalid, thus skipping the error value and falling back to the default text-mode. Care should be taking while testing to identify any possible issues with displaying the grub menu or outputting information from the kernel at console as the system boots (if applicable).

  ---

  In a Ubuntu 16.04.6 VM, which runs as a Gen2 VM on Hyper-V, I add
  GRUB_GFXPAYLOAD_LINUX="text" into /etc/default/grub and run update-
  grub; next, grub2 prints the below error:

  error: invalid video mode specification `text'.
  Booting in blind mode

  This means grub2 passes a zero value for the "lfb_base" to Linux
  kernel, which then fails to reserve the framebuffer MMIO range in
  drivers/hv/vmbus_drv.c: vmbus_reserve_fb(); as a result, when we pass
  through a PCIe device to the VM, the PCIe device may get a PCI MMIO
  BAR in the FB MMIO range, causing a conflict, and the PCIe device can
  not work in the VM.

  The issue can not reproduce with Ubuntu 18.04. It turns out the grub2 in Ubuntu 18.04 has the below fix:
  video: skip 'text' gfxpayload if not supported, to fallback to default (https://git.launchpad.net/~ubuntu-core-dev/grub/+git/ubuntu/commit/?id=38d9e2f862a96a039ae8ca8b87b8615d154ceda4).

  I'm asking the patch author (Mathieu Trudel-Lapierre) to submit the
  patch to the upstream grub and this is the upstream bug link:
  https://savannah.gnu.org/bugs/?56217 .

  Here this launchpad bug is for Ubuntu 16.04 and 14.04.

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