Cc: Ganpatrao, Steve, Tanmay
On 04/08/2023 11:13, James Clark wrote:
Hi,
I'm looking for help in testing this and for feedback on whether it's useful to anyone. Testing it requires hardware that has Feat_TRF (v8.4) but no TRBE. This is because TRBE usage is disabled in nVHE guests.
I don't currently have any access to any hardware, and the FVP model can only do self hosted trace using TRBE.
If you have a v8.4+ (and not v9) HW, please could you give this a spin ?
Suzuki
Currently with nVHE you would always get trace from guests, and filtering out isn't possible without this patchset. In comparison, with VHE guests, they never generate guest trace without [1]. I think the existence of trace rather than lack of could suggest that this change is less useful than [1]. Also the restricted set of hardware that it works on supports that too.
Apart from compilation and checking that the exclude guest settings are correctly programmed on guest switch, this is untested by me.
Applies to kvmarm/next (3b4e3afb2032)
James Clark (3): arm64: KVM: Add support for exclude_guest and exclude_host for ETM arm64: KVM: Support exclude_guest for Coresight trace in nVHE coresight: Support exclude_guest with Feat_TRF and nVHE
arch/arm64/include/asm/kvm_host.h | 10 +++- arch/arm64/kvm/Makefile | 1 + arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/debug.c | 7 +++ arch/arm64/kvm/etm.c | 48 ++++++++++++++++ arch/arm64/kvm/hyp/nvhe/debug-sr.c | 56 +++++++++++++++++-- .../hwtracing/coresight/coresight-etm-perf.c | 4 ++ include/kvm/etm.h | 43 ++++++++++++++ 8 files changed, 165 insertions(+), 5 deletions(-) create mode 100644 arch/arm64/kvm/etm.c create mode 100644 include/kvm/etm.h