Hi Konstantin,
On 8/25/2026 11:22 AM, Konstantin Semichastnov wrote:
Hi,
This series continues to implement RISC-V tracing subsystem.
This work implements RISC-V N-Trace (Nexus-based Trace) [1].
N-Trace is a different format for tracing (compared to E-Trace [2]),
and it is based on same underlying interface: RISC-V Trace Control
Interface Specification [3].
This is the first patchset of several upcoming patchset series,
that will ultimately provide full support for N-Trace HTM tracing.
A design decision was chosen to make the most of the existing
infrastructure of the trace subsystem.
Linux kernel driver support is available here:
https://lore.kernel.org/linux-riscv/[email protected]/
Patches based on Daniel's Efficient Trace patchset [4],
which provides support for Trace Control Interface and E-Trace messages
implementation.
I *really* need to re-send that series. I'll do that as soon as I clear up
pending
work to avoid holding this series back when it's time to merge it.
Since you're using that series as a base I'll keep you in the loop if I make
some
drastic changes in it. I don't think I will - what comes to mind is some TCG
side
changes to take advantage of the extra tb_flags we have now.
I remember from those reviews that we were doing changes in that e-trace
message code.
I'll keep that code intact, and in case you decide we need changes we can do it
as
a follow-up when stuff is already accepted.
Also, please update my email in the CC in the next versions of this work. That
email
is still around but not sure for how long ...
Thanks,
Daniel
[1] https://docs.riscv.org/reference/nexus-trace/_attachments/RISC-V-N-Trace.pdf
[2] https://docs.riscv.org/reference/e-trace/_attachments/riscv-trace-spec.pdf
[3]
https://docs.riscv.org/reference/trace-control-interface/_attachments/RISC-V-Trace-Control-Interface.pdf
[4]
https://lore.kernel.org/qemu-riscv/[email protected]
Based-on: <[email protected]>
Signed-off-by: Konstantin Semichastnov <[email protected]>
---
Konstantin Semichastnov (13):
hw/riscv/trace-encoder: add ntrace enable flag
hw/riscv/trace-encoder.c: add trace ntrace/etrace selection logic
hw/riscv: add n-trace encoder with ProgTraceSync message
hw/riscv/trace-encoder.c: align ntrace messages with ones
hw/riscv/trace_encoder, target/riscv: add trace pc history logic
hw/riscv: add n-trace IndirectBranchHist rv-trace-message
hw/riscv/trace-encoder: add interrupt support to N-Trace encoder
hw/riscv: add n-trace ResourceFull rv-trace-message
hw/riscv: add n-trace ProgTraceCorrelation rv-trace-message
test/qtest/riscv-trace-test: add test-ntrace-simple qtest
hw/riscv/trace-encoder.c: add remaining fields to trace-encoder
hw/riscv/trace-encoder.c: remaining fields to ram-sink as RO values
hw/riscv/trace-encoder: refactor register accesses
disas/riscv.c | 2 +-
disas/riscv.h | 2 +
hw/riscv/rv-trace-messages.c | 265 ++++++++++++++++++++
hw/riscv/rv-trace-messages.h | 10 +
hw/riscv/trace-encoder.c | 332 +++++++++++++++++++++----
hw/riscv/trace-encoder.h | 49 +++-
hw/riscv/trace-ram-sink.c | 22 +-
hw/riscv/trace-ram-sink.h | 1 +
target/riscv/cpu_helper.c | 21 +-
target/riscv/helper.h | 4 +-
target/riscv/insn_trans/trans_privileged.c.inc | 10 +-
target/riscv/insn_trans/trans_rvi.c.inc | 15 +-
target/riscv/trace_helper.c | 23 +-
target/riscv/translate.c | 19 +-
tests/qtest/riscv-trace-test.c | 59 ++++-
15 files changed, 734 insertions(+), 100 deletions(-)
---
base-commit: 6cedd046f606f155e054375c369bd606313e5f6c
change-id: 20260825-upstream-ntrace_core-49bff943062d
Best regards,
--
Konstantin Semichastnov <[email protected]>
