[Bug 1826453] Re: Grub2 Booting in blind mode due to "invalid video mode specification `text'"

[Dexuan Cui]

Hi Mathieu, 
Thanks for the hint! After I changed the Pin-Priority from 400 to 600 in the below file, I successfully installed the *3.22 version:

root at decui-g2-1604:~# cat /etc/apt/preferences.d/proposed-updates
Package: *
Pin: release a=xenial-proposed
Pin-Priority: 600

...

root at decui-g2-1604:~# apt policy grub2-common
grub2-common:
  Installed: 2.02~beta2-36ubuntu3.22
  Candidate: 2.02~beta2-36ubuntu3.22
  Version table:
 *** 2.02~beta2-36ubuntu3.22 600
        600 http://archive.ubuntu.com/ubuntu xenial-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     2.02~beta2-36ubuntu3.21 500
        500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
     2.02~beta2-36ubuntu3 500
        500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages

And I can confirm the issue is fixed for "16.04.6 LTS (Xenial Xerus)"!

Now in the VM running on Hyper-V, I get the below as expected
(previously I can not see the line with the *3.21 version of grub2):

root at decui-g2-1604:~# dmesg | grep "efifb: framebuffer"
[    0.472000] efifb: framebuffer at 0xf8000000, mapped to 0xffffc90001c00000, using 3072k, total 3072k


Thank you all for the quick response!

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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:
  Fix Released
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:
  Fix Committed

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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