Hi,
This series adds basic support for running nested guests (L2) in
kselftest. The first patch adds library functions. While designing the
APIs for userspace, I referenced Joey's approach for kvm-unit-tests [1].
In summary, four preparatory functions are provided for userspace to
set up state to run an L2 in EL1:
- prepare_l2_stack() <- sets up stack for L2
- prepare_hyp_state() <- sets up vEL2 registers
- prepare_eret_destination() <- userspace passes a function pointer
for L2 to run
- prepare_nested_sync_handler() <- sets up hvc handler in order to
regain control after L2's hvc
After calling those functions, userspace can vcpu_run(), and when
run_l2() is called within the guest, the supplied function will be run
in L2, with the control flow managed by the library code in nested.c and
nested_asm.S. After running the L2 function, run_l2() will automatically
return. Note that the L2 function supplied by the user does not have to
call hvc.
Patch 2 demonstrates usage of the APIs introduced above, with a simple
L1 -> L2 -> L1 sequence, with an empty L2 function.
Patch 3 enhances the library functions by setting up L2 -> L1 stage-2
translation. Currently the translation is simple, with start level 0, 4
levels, 4KB granules, normal cachable, 48-bit IA, 40-bit OA.
[1]: https://lore.kernel.org/kvmarm/[email protected]/
Wei-Lin Chang (3):
KVM: arm64: selftests: Add library functions for NV
KVM: arm64: sefltests: Add basic NV selftest
KVM: arm64: selftests: Enable stage-2 in NV preparation functions
tools/testing/selftests/kvm/Makefile.kvm | 3 +
.../selftests/kvm/arm64/hello_nested.c | 65 ++++++++
.../selftests/kvm/include/arm64/nested.h | 25 +++
.../selftests/kvm/include/arm64/processor.h | 9 +
.../testing/selftests/kvm/lib/arm64/nested.c | 154 ++++++++++++++++++
.../selftests/kvm/lib/arm64/nested_asm.S | 35 ++++
6 files changed, 291 insertions(+)
create mode 100644 tools/testing/selftests/kvm/arm64/hello_nested.c
create mode 100644 tools/testing/selftests/kvm/include/arm64/nested.h
create mode 100644 tools/testing/selftests/kvm/lib/arm64/nested.c
create mode 100644 tools/testing/selftests/kvm/lib/arm64/nested_asm.S
--
2.43.0
