Hi, Per Daniel's review feedback, this v5 series is based on Alistair's riscv-to-apply.next branch [3]. It depends on patches 1-5 of Max Chou's "Add Zvfbfa extension support" v2 series (not included; apply them first) [2]. It is based on RISC-V Debug Specification 1.0 [1]. It introduces the sdext/sdtrig config bits, DCSR/DPC/DSCRATCH state, Debug Mode enter/leave helpers, DRET, EBREAK entry, single-step, and trigger action=debug mode. To reduce review load, this series focuses on the Sdext features first. The Debug Module (DM) and related flows will follow in a later series. Changes in v5: - Patch 2: removed redundant `cpu->cfg.ext_sdext = false;` in riscv_cpu_init() since it's already set to false in MULTI_EXT_CFG_BOOL. (Daniel) - Patch 7: changed LOG_UNIMP to LOG_GUEST_ERROR for invalid trigger action=debug mode when Sdext is not enabled. LOG_UNIMP is reserved for unimplemented features, while LOG_GUEST_ERROR is for invalid guest actions. (Daniel) Changes in v4: - Fixed linux-user build errors: moved debug_mode/dcsr/dpc/dscratch fields inside #ifndef CONFIG_USER_ONLY block in cpu.h, and wrapped all code using these fields with proper guards. (Daniel) - Updated dependency from single patch (patch 5 only) to patches 1-5 of Max Chou's "Add Zvfbfa extension support" v2 series to avoid compilation errors. Changes in v3: - Rebase onto Alistair's riscv-to-apply.next branch. - Depend on Max Chou's patch "target/riscv: Use the tb->cs_bqse as the extend tb flags." (not included; apply it first) [2]. - Patch 2: default sdext to false in riscv_cpu_extensions[]. Changes in v2: - Drop the RHCT expected AML update from this series. - Replace the split sdext/sdtrig config bits patch with deprecating the 'debug' CPU property. - Rebase and update patch subjects to target/riscv prefix. Changes in v1: - Debug Mode entry/exit updates DCSR/DPC and restores execution via DRET. - EBREAK honors DCSR ebreak bits and enters Debug Mode when enabled. - Single-step uses DCSR.STEP with a TB flag and a helper at TB exit. It references Max Chou's patch "target/riscv: Use the tb->cs_bqse as the extend tb flags." [2]. - Sdtrig supports action=debug mode for mcontrol/mcontrol6 and reports inst-count triggers in tinfo. Differences vs Debug Spec (known gaps): - No Debug Module (no DMI, dmcontrol/dmstatus, haltreq/resumereq). - No debug ROM, program buffer, abstract commands, or SBA. - Resume is modeled by leaving Debug Mode at cpu_exec_enter. - Step/exception ordering is simplified: if the stepped instruction traps, the normal exception is taken and Debug Mode is not forced. - Several DCSR fields are not fully modeled (stopcount/stoptime, etc). Roadmap (next stage, DM focus): 1) Add a DM core with DMI access and hart state tracking. 2) Implement halt/resume handshake and move Debug Mode transitions under DM control. 3) Add debug ROM, program buffer, and abstract commands for GPR/CSR and memory access. 4) Add SBA if required by tooling. 5) Tighten ordering rules for step/exception/trigger priorities. References: [1] https://github.com/riscv/riscv-debug-spec/releases/tag/1.0 [2] https://lore.kernel.org/qemu-devel/20260108132631.9429-1-max.chou@sifive.com... [3] https://github.com/alistair23/qemu/tree/riscv-to-apply.next Thanks, Chao Chao Liu (6): target/riscv: add sdext debug CSRs state target/riscv: add sdext Debug Mode helpers target/riscv: add dret instruction target/riscv: add sdext enter Debug Mode on ebreak target/riscv: add sdext single-step support target/riscv: add sdtrig trigger action=debug mode Daniel Henrique Barboza (1): target/riscv: deprecate 'debug' CPU property docs/about/deprecated.rst | 7 + include/exec/translation-block.h | 4 +- target/riscv/cpu.c | 59 +++++++- target/riscv/cpu.h | 9 ++ target/riscv/cpu_bits.h | 33 +++++ target/riscv/cpu_cfg_fields.h.inc | 3 +- target/riscv/cpu_helper.c | 90 ++++++++++++ target/riscv/csr.c | 128 +++++++++++++++++- target/riscv/debug.c | 58 +++++++- target/riscv/helper.h | 3 + target/riscv/insn32.decode | 1 + .../riscv/insn_trans/trans_privileged.c.inc | 24 ++++ target/riscv/machine.c | 44 ++++-- target/riscv/op_helper.c | 70 ++++++++++ target/riscv/tcg/tcg-cpu.c | 21 ++- target/riscv/translate.c | 16 ++- 16 files changed, 545 insertions(+), 25 deletions(-) -- 2.53.0