[Bug 2076651] Re: [SRU] Crash on RISC-V in virtual machine using KVM

[Heinrich Schuchardt]

** Description changed:

  [ Impact ]
  
  On RISC-V hardware offering the hypervisor extension GRUB crashes in
  virtual machines running under KVM due  to missing accessibility of the
  counter register.
  
  For measuring time the RISC-V ISA provides the time register.
  
  Please, apply the following patch:
  
  [PATCH 1/1] riscv: use time register in grub_efi_get_time_ms()
  https://lists.gnu.org/archive/html/grub-devel/2024-08/msg00008.html
  
  [ Test Plan ]
  
+ To reproduce the error run Ubuntu on QEMU according to
+ https://wiki.ubuntu.com/RISC-V/QEMU on an HiFive P550 Premier. Add
+ '-accel kvm' to the command line to use KVM. GRUB crashes.
+ 
  Run Ubuntu on QEMU according to https://wiki.ubuntu.com/RISC-V/QEMU.
  
  In GRUB press the <C>-key to enter the console.
  
  Execute 'sleep 10' and check that the console prompt is written after
  approximately 10 seconds.
  
  Restart the VM with the 'reset' command.
  
  Check that the countdown in the Ubuntu menu runs at wall time speed.
  
  Check that the login prompt is reached.
  
+ Correct timing under KVM depends on LP #2076927.
+ 
  [ Where problems could occur ]
  
  The patch only concerns RISC-V. It changes how GRUB measures elapsed
  time.
  
  Incorrect measuring of time could lead to the menu countdown or the
  sleep command not working.
  
  [ Other Info ]
-  
+ 
  n/a

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https://bugs.launchpad.net/bugs/2076651

Title:
  [SRU] Crash on RISC-V in virtual machine using KVM

Status in grub2 package in Ubuntu:
  New
Status in grub2 source package in Noble:
  New
Status in grub2 source package in Oracular:
  New

Bug description:
  [ Impact ]

  On RISC-V hardware offering the hypervisor extension GRUB crashes in
  virtual machines running under KVM due  to missing accessibility of
  the counter register.

  For measuring time the RISC-V ISA provides the time register.

  Please, apply the following patch:

  [PATCH 1/1] riscv: use time register in grub_efi_get_time_ms()
  https://lists.gnu.org/archive/html/grub-devel/2024-08/msg00008.html

  [ Test Plan ]

  To reproduce the error run Ubuntu on QEMU according to
  https://wiki.ubuntu.com/RISC-V/QEMU on an HiFive P550 Premier. Add
  '-accel kvm' to the command line to use KVM. GRUB crashes.

  Run Ubuntu on QEMU according to https://wiki.ubuntu.com/RISC-V/QEMU.

  In GRUB press the <C>-key to enter the console.

  Execute 'sleep 10' and check that the console prompt is written after
  approximately 10 seconds.

  Restart the VM with the 'reset' command.

  Check that the countdown in the Ubuntu menu runs at wall time speed.

  Check that the login prompt is reached.

  Correct timing under KVM depends on LP #2076927.

  [ Where problems could occur ]

  The patch only concerns RISC-V. It changes how GRUB measures elapsed
  time.

  Incorrect measuring of time could lead to the menu countdown or the
  sleep command not working.

  [ Other Info ]

  n/a

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