[PATCH 0/4] KVM nVHE Hypervisor stack unwinder

[Kalesh Singh]

Hi all,

This series is based on arm64 for-next/core and is also dependent
on the series at [1].

A previous version of hypervisor stack unwinding was included
in the series at [2].

This new version of the unwinder splits the unwinding and dumping
of the stack between the hypervisor and host:
  - The hyperviosr unwinds its stack and dumps the address entries
    into a page shared with the host.
  - The host then symnolizes and prints the hyp stacktrace from
    the shared page.

The new approach doesn't depend on CONFIG_NVHE_EL2_DEBUG,
and allows dumping hyp stacktraces in prodcution environments
(!CONFIG_NVHE_EL2_DEBUG).

arm64/kernel/stacktrace.c is compiled twice: stacktrace.o for the
host kernel and stacktrace.nvhe.o for the hypervisor: This allows
reusing most of the host unwinding logic in the nVHE hypervisor.

[1] https://lore.kernel.org/r/20220420214317.3303360-1-kaleshsingh@google.com/
[2] https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/

Thanks,
Kalesh


Kalesh Singh (4):
  KVM: arm64: Compile stacktrace.nvhe.o
  KVM: arm64: Add hypervisor overflow stack
  KVM: arm64: Allocate shared stacktrace pages
  KVM: arm64: Unwind and dump nVHE hypervisor stacktrace

 arch/arm64/include/asm/kvm_asm.h    |   1 +
 arch/arm64/include/asm/stacktrace.h |  58 +++++++++--
 arch/arm64/kernel/stacktrace.c      | 151 +++++++++++++++++++++++-----
 arch/arm64/kvm/arm.c                |  34 +++++++
 arch/arm64/kvm/handle_exit.c        |   4 +
 arch/arm64/kvm/hyp/nvhe/Makefile    |   3 +-
 arch/arm64/kvm/hyp/nvhe/host.S      |   9 +-
 arch/arm64/kvm/hyp/nvhe/setup.c     |  11 ++
 arch/arm64/kvm/hyp/nvhe/switch.c    |   4 +
 9 files changed, 231 insertions(+), 44 deletions(-)

-- 
2.36.0.rc2.479.g8af0fa9b8e-goog