The following patches implement support for debugging of KVM guests on arm64 hardware. It supports SW and HW break points as well as single-step functionality. I've created a branch of QEMU with the userspace support to test this at: https://github.com/stsquad/qemu/tree/kvm/guest-debug-kvm-submission I've done some initial manual testing and everything seems fine but I have yet to write my test suite. One area which has not yet been tested is debug inside the guest while being debugged. The current implementation effectively suspends the guests ability to use single step and HW assisted debugging while KVM is debugging it. However the door is open to userspace trying to accommodate this mode as the guest's view of debugging registers is separate from actual values when guest debugging is in operation. The first 3 patches simply lay the groundwork for the later functionality. Each patch then introduces each bit of functionality except the re-factor patch which I split out from the HW assisted debug patch to aid review. In reference to the recent discussion about exposing the number of debug registers to userspace I ended up using the KVM_EXTENSION ioctl which helpfully allows to return of any positive number for success. It seemed by far the simplest API to use from both the kernel and userspace point of view. The patches all pass checkpatch apart from the changes to asm-offsets.c which complain about leading spaces and long lines. I left them as is to fit in with the formatting of the rest of the file. Alex Bennée (7): KVM: add commentary for kvm_debug_exit_arch struct KVM: arm: guest debug, define API headers KVM: arm: guest debug, add stub KVM_SET_GUEST_DEBUG ioctl KVM: arm64: guest debug, add SW break point support KVM: arm64: guest debug, add support for single-step KVM: arm64: re-factor hyp.S debug register code KVM: arm64: guest debug, HW assisted debug support Documentation/virtual/kvm/api.txt | 11 +- arch/arm/kvm/arm.c | 89 +++++++++- arch/arm64/include/asm/hw_breakpoint.h | 12 ++ arch/arm64/include/asm/kvm_host.h | 4 +- arch/arm64/include/uapi/asm/kvm.h | 28 ++++ arch/arm64/kernel/asm-offsets.c | 6 + arch/arm64/kernel/hw_breakpoint.c | 12 -- arch/arm64/kvm/handle_exit.c | 80 +++++++++ arch/arm64/kvm/hyp.S | 292 ++++++++++++++------------------- arch/arm64/kvm/reset.c | 6 + include/uapi/linux/kvm.h | 21 ++- 11 files changed, 371 insertions(+), 190 deletions(-) -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
