This series enables Control Transfer Records extension support on riscv platform. This extension is similar to Arch LBR in x86 and BRBE in ARM. The Extension has been stable and the latest release can be found here [0]
CTR extension depends on couple of other extensions: 1. S[m|s]csrind : The indirect CSR extension [1] which defines additional ([M|S|VS]IREG2-[M|S|VS]IREG6) register to address size limitation of RISC-V CSR address space. CTR access ctrsource, ctrtartget and ctrdata CSRs using sscsrind extension. 2. Smstateen: The mstateen bit[54] controls the access to the CTR ext to S-mode. 3. Sscofpmf: Counter overflow and privilege mode filtering. [2] The series is based on Smcdeleg/Ssccfg counter delegation extension [3] patches. CTR itself doesn't depend on counter delegation support. This rebase is basically to include the Smcsrind patches. Due to the dependency of these extensions, the following extensions must be enabled to use the control transfer records feature. "smstateen=true,sscofpmf=true,smcsrind=true,sscsrind=true,smctr=true,ssctr=true" Here is the link to a quick guide [5] to setup and run a basic perf demo on Linux to use CTR Ext. The Qemu patches can be found here: https://github.com/rajnesh-kanwal/qemu/tree/ctr_upstream_v2 The opensbi patch can be found here: https://github.com/rajnesh-kanwal/opensbi/tree/ctr_upstream_v2 The Linux kernel patches can be found here: https://github.com/rajnesh-kanwal/linux/tree/ctr_upstream_v2 [0]: https://github.com/riscv/riscv-control-transfer-records/release [1]: https://github.com/riscv/riscv-indirect-csr-access [2]: https://github.com/riscvarchive/riscv-count-overflow/tree/main [3]: https://github.com/riscv/riscv-smcdeleg-ssccfg [4]: https://lore.kernel.org/all/20240217000134.3634191-1-ati...@rivosinc.com/ [5]: https://github.com/rajnesh-kanwal/linux/wiki/Running-CTR-basic-demo-on-QEMU-RISC%E2%80%90V-Virt-machine Changelog: v2: Lots of improvements based on Jason Chien's feedback including: - Added CTR recording for cm.jalt, cm.jt, cm.popret, cm.popretz. - Fixed and added more CTR extension enable checks. - Fixed CTR CSR predicate functions. - Fixed external trap xTE bit checks. - One fix in freeze function for VS-mode. - Lots of minor code improvements. - Added checks in sctrclr instruction helper. v1: - https://github.com/rajnesh-kanwal/qemu/tree/ctr_upstream Rajnesh Kanwal (6): target/riscv: Remove obsolete sfence.vm instruction target/riscv: Add Control Transfer Records CSR definitions. target/riscv: Add support for Control Transfer Records extension CSRs. target/riscv: Add support to record CTR entries. target/riscv: Add CTR sctrclr instruction. target/riscv: Add support to access ctrsource, ctrtarget, ctrdata regs. target/riscv/cpu.c | 4 + target/riscv/cpu.h | 14 + target/riscv/cpu_bits.h | 154 ++++++++++ target/riscv/cpu_cfg.h | 2 + target/riscv/cpu_helper.c | 265 +++++++++++++++++ target/riscv/csr.c | 276 +++++++++++++++++- target/riscv/helper.h | 9 +- target/riscv/insn32.decode | 2 +- .../riscv/insn_trans/trans_privileged.c.inc | 21 +- target/riscv/insn_trans/trans_rvi.c.inc | 31 ++ target/riscv/insn_trans/trans_rvzce.c.inc | 20 ++ target/riscv/op_helper.c | 159 +++++++++- target/riscv/tcg/tcg-cpu.c | 6 + target/riscv/translate.c | 10 + 14 files changed, 960 insertions(+), 13 deletions(-) -- 2.34.1
