[PATCH v8 00/13] Add RISC-V ISA extension smcntrpmf support

[Atish Patra]

This patch series adds the support for RISC-V ISA extension smcntrpmf (cycle and
privilege mode filtering) [1]. It is based on Kevin's earlier work but improves
it by actually implement privilege mode filtering by tracking the privilege
mode switches. This enables the privilege mode filtering for mhpmcounters as
well. However, Smcntrpmf/Sscofpmf must be enabled to leverage this.

The series is also available at [2] as well.

Changes in v8:
- Moved the config option to a separate patch at the end of the series.  
- Fixed a comments recieved in v7 around setting INH bit based on available 
priv modes.
- Updated the RB/AB tags.
- Link to v7: 
https://lore.kernel.org/r/20240626-smcntrpmf_v7-v7-0-bb0f10af7fa9@rivosinc.com

Changes from v6->v7:
1. Fixed a compilation issue.

Changes from v5->v6:
1. Rebased on top of alister/riscv-to-apply.next (c50aabe132) and icount fix
   patch[4] which may cause conflicts.
2. Fixed a bug in pmf logic related to VS<->HS transition and same mode
   recording.
3. Merged assorted fixes PR as the changes are intertwined. [2]
4. Fix counter inhibit CSR behavior. This change now start counters from both
   mhpmcounter and mcountinhibit writes. Previously cycle/inst timer was
   only started on mhpmcounterx write.
5. Optimized the PMU timer setup code.

Changes from v4->v5:
1. Rebased on top of master(158a054c4d1a).
2. Fixed a bug for VS<->HS transition.

Changes from v3->v4:
1. Fixed the ordering of the ISA extension names in isa_edata_arr.
2. Added RB tags.

Changes from v2->v3:
1. Fixed the rebasing error in PATCH2.
2. Added RB tags.
3. Addressed other review comments.

Changes from v1->v2:
1. Implemented actual mode filtering for both icount and host ticks mode.
1. Addressed comments in v1.
2. Added Kevin's personal email address.

[1] https://github.com/riscv/riscv-smcntrpmf
[2] https://github.com/atishp04/qemu/tree/b4/smcntrpmf_v7
[3] 
https://lore.kernel.org/all/20240429-countinhibit_fix-v1-0-802ec1e99133@rivosinc.com/
[4] 
https://lore.kernel.org/qemu-riscv/20240618112649.76683-1-cleger@rivosinc.com/

Cc: Rajnesh Kanwal <rkanwal@rivosinc.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
Atish Patra (7):
      target/riscv: Fix the predicate functions for mhpmeventhX CSRs
      target/riscv: Only set INH fields if priv mode is available
      target/riscv: Implement privilege mode filtering for cycle/instret
      target/riscv: Save counter values during countinhibit update
      target/riscv: Enforce WARL behavior for scounteren/hcounteren
      target/riscv: Do not setup pmu timer if OF is disabled
      target/riscv: Expose the Smcntrpmf config

Kaiwen Xue (3):
      target/riscv: Add cycle & instret privilege mode filtering properties
      target/riscv: Add cycle & instret privilege mode filtering definitions
      target/riscv: Add cycle & instret privilege mode filtering support

Rajnesh Kanwal (3):
      target/riscv: Combine set_mode and set_virt functions.
      target/riscv: Start counters from both mhpmcounter and mcountinhibit
      target/riscv: More accurately model priv mode filtering.

 target/riscv/cpu.c        |   2 +
 target/riscv/cpu.h        |  20 ++-
 target/riscv/cpu_bits.h   |  41 +++++
 target/riscv/cpu_cfg.h    |   1 +
 target/riscv/cpu_helper.c |  66 +++----
 target/riscv/csr.c        | 437 +++++++++++++++++++++++++++++++++++++---------
 target/riscv/machine.c    |   5 +-
 target/riscv/op_helper.c  |  17 +-
 target/riscv/pmu.c        | 181 +++++++++++++++++--
 target/riscv/pmu.h        |   4 +
 10 files changed, 624 insertions(+), 150 deletions(-)
---
base-commit: 842a3d79a0e37cd3d685c4728308fac0d9bfd0bb
change-id: 20240626-smcntrpmf_v7-3b275d1da117
--
Regards,
Atish patra