[PATCH v2 0/6] Exception handling in HYP mode on ARMv7-A

Jim Posen jim.posen at gmail.com
Wed Nov 24 20:39:55 CET 2021

Currently, when U-Boot is running in hypervisor mode on ARMv7-A CPUs
with virtualization extensions, the exception handling does not work.
A couple things need to change which are detailed in my earlier
message to the u-boot mailing list with the subject "Exception
handling in HYP mode on ARMv7-A".

I have verified that this patch series works on the ODroid XU4 and
the Raspberry Pi 3B in Aarch32 mode when running in hypervisor mode.
One simple way to verify is by running the miscellaneous "exception"
command (CMD_EXCEPTION).

This can be tested with QEMU now. Configure with qemu_arm_defconfig

qemu-system-arm \
    -machine virt,virtualization \
                -nographic -serial mon:stdio \
                -bios u-boot.bin

U-Boot 2021.10-...
=> exception undefined

Changes in v2:
- Fix CP15 register written to in start.S
- Check processor mode as HVBAR register is only accessible in HYP
- Add QEMU config option for ARM32 with virtualization extensions

Jim Posen (6):
  Compile for ARMv7-A with virtualization extensions
  Hypervisor mode interrupt vector table
  Set HVBAR register correctly
  Remove dead code
  Fix PC adjustment logic in exception handlers
  Config to target QEMU virt machine with virtualization

 arch/arm/Makefile                 |   4 +
 arch/arm/cpu/armv7/start.S        |   8 ++
 arch/arm/include/asm/u-boot-arm.h |  14 ++--
 arch/arm/lib/interrupts.c         |  26 +++---
 arch/arm/lib/relocate.S           |  13 +++
 arch/arm/lib/vectors.S            | 129 +++++++++++++++++++++++-------
 arch/arm/mach-bcm283x/Kconfig     |   3 +
 arch/arm/mach-exynos/Kconfig      |   1 +
 arch/arm/mach-qemu/Kconfig        |   6 ++
 9 files changed, 153 insertions(+), 51 deletions(-)


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