The CXL subsystem in QEMU currently has no trace coverage. Debugging
mailbox commands, HDM decoder programming, event log activity, and
CFMWS address decoding relies on temporary printf or qemu_log_mask.
This series introduces trace-events infrastructure for the CXL
subsystem and adds 11 trace points covering the above paths. All
events use the cxl_ prefix so -trace 'cxl_*' captures everything.
Changes since v1:
- Split patch 2 into HDM-only; dropped CDAT traces -- source is
commandline-controlled (Jonathan)
- Split patch 3 into separate event-log and CFMWS patches (Jonathan)
- Pass set and cmd as separate uint8_t parameters instead of a
combined opcode (Jonathan)
- Cover all 21 CXL_MBOX_INVALID_PAYLOAD_LENGTH return sites, not
just the centralised entry check (Jonathan)
- Rename depth -> occupancy in event log trace (Jonathan)
- Defer passthrough-specific trace pending upstream support (Jonathan)
- Add cxl_hdm_decoder_uncommit for commit/uncommit symmetry
v1:
https://lore.kernel.org/qemu-devel/[email protected]/
Junjie Cao (5):
hw/cxl: introduce trace-events infrastructure
hw/cxl: trace mailbox command dispatch and payload errors
hw/cxl: trace HDM decoder write, commit and uncommit
hw/cxl: trace event log insertion, overflow and clear
hw/cxl: trace CFMWS address-to-device routing
hw/cxl/cxl-events.c | 13 +++++--
hw/cxl/cxl-host.c | 4 +++
hw/cxl/cxl-mailbox-utils.c | 71 +++++++++++++++++++++++++++++++++++--
hw/cxl/trace-events | 15 ++++++++
hw/cxl/trace.h | 2 ++
hw/mem/cxl_type3.c | 19 +++++++++-
hw/mem/trace-events | 5 +++
include/hw/cxl/cxl_device.h | 1 +
meson.build | 1 +
9 files changed, 126 insertions(+), 5 deletions(-)
create mode 100644 hw/cxl/trace-events
create mode 100644 hw/cxl/trace.h
--
2.43.0
