Thank you for pointing that out. CTR does not use miselect and
mireg*. There is no dependency on Smcsrind. I believe the spec
needs to be corrected.
Chapter 1 states that:
Smctr depends on the Smcsrind extension, while Ssctr depends on
the Sscsrind extension. Further, both Smctr and Ssctr depend upon
implementation of S-mode.
Beeman Strong 於 2024/6/5 上午 06:32 寫道:
There is no dependency on Smcsrind, only
Sscsrind.
Smctr
depends on the Smcsrind extension, Ssctr depends on the
Sscsrind
extension, and both Smctr and Ssctr depend upon
implementation of S-mode.
There should be a dependency check in
riscv_cpu_validate_set_extensions().
Rajnesh Kanwal 於 2024/5/30 上午 12:09 寫道:
> 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
>
> The opensbi patch can be found here:
> https://github.com/rajnesh-kanwal/opensbi/tree/ctr_upstream
>
> The Linux kernel patches can be found here:
> https://github.com/rajnesh-kanwal/linux/tree/ctr_upstream
>
> [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-atishp@rivosinc.com/
> [5]:https://github.com/rajnesh-kanwal/linux/wiki/Running-CTR-basic-demo-on-QEMU-RISC%E2%80%90V-Virt-machine
>
> 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 | 213
++++++++++++
> target/riscv/csr.c | 312
+++++++++++++++++-
> target/riscv/helper.h | 8
+-
> target/riscv/insn32.decode | 2
+-
> .../riscv/insn_trans/trans_privileged.c.inc | 21
+-
> target/riscv/insn_trans/trans_rvi.c.inc | 27
++
> target/riscv/op_helper.c | 117
++++++-
> target/riscv/translate.c | 9 +
> 12 files changed, 870 insertions(+), 13 deletions(-)
>