[PATCH v5 00/15] riscv support for control flow integrity extensions

[Deepak Gupta]

v5 for riscv zicfilp and zicfiss extensions support in qemu.

Links for previous versions
[1] - v1 https://lists.nongnu.org/archive/html/qemu-devel/2024-07/msg06017.html
[2] - v2 
https://lore.kernel.org/all/ed23bcbc-fdc4-4492-803c-daa95880375a@linaro.org/T/
[3] - v3 https://lists.nongnu.org/archive/html/qemu-devel/2024-08/msg01005.html
[4] - v4 
20240816010711.3055425-6-debug@rivosinc.com/T/">https://lore.kernel.org/all/20240816010711.3055425-6-debug@rivosinc.com/T/

---
v5:
   - Simplified elp tracking and lpad implementation as per suggestion by 
richard
   - Simplified shadow stack mmu checks as per suggestion by richard
   - Converged zicfiss compressed and non-comressed instructions to same 
translation
   - Removed trace hooks. Don't need for upstream.

v4:
   - elp state in cpu is true/false instead of enum and elp cleared
     unconditionally on trap entry. elp in *status cleared unconditionally on
     trap return. 
   - Moved logic for branch tracking in instruction translation from tb_start.
   - fixed zicfiss dependency on 'A'
   - `cpu_get_fcfien/bcfien` helpers checks fixed to check for extension first.
   - removed trace hook enums. Instead added dedicated trace helpers wherever 
needed.
   - fixed/simplified instruction format in decoder for lpad, sspush, sspopchk
   - simplified tlb index logic for shadow stack instructions. Removed SUM 
TB_FLAG
   - access to ssp CSR is gated on `cpu_get_bcfien` instead of duplicated logic
   - removed vDSO related changes for now. 
v3:
   - Removed prctl specific patches because they need to be upstream
     in kernel first.
   - As suggested by Richard, added TB flag if fcfi enabled
   - Re-worked translation for landing pad and shadow stack instructions
     to not require helper.
   - tcg helpers only for cfi violation cases so that trace hooks can be
     placed.
   - Style changes.
   - fixes assert condition in accel/tcg

v2:
   - added missed file (in v1) for shadow stack instructions implementation.

Deepak Gupta (15):
  target/riscv: Add zicfilp extension
  target/riscv: Introduce elp state and enabling controls for zicfilp
  target/riscv: save and restore elp state on priv transitions
  target/riscv: additional code information for sw check
  target/riscv: tracking indirect branches (fcfi) for zicfilp
  target/riscv: zicfilp `lpad` impl and branch tracking
  disas/riscv: enable `lpad` disassembly
  target/riscv: Add zicfiss extension
  target/riscv: introduce ssp and enabling controls for zicfiss
  target/riscv: tb flag for shadow stack  instructions
  target/riscv: mmu changes for zicfiss shadow stack protection
  target/riscv: implement zicfiss instructions
  target/riscv: compressed encodings for sspush and sspopchk
  disas/riscv: enable disassembly for zicfiss instructions
  disas/riscv: enable disassembly for compressed sspush/sspopchk

 disas/riscv.c                                 |  77 +++++++++-
 disas/riscv.h                                 |   4 +
 target/riscv/cpu.c                            |  17 +++
 target/riscv/cpu.h                            |  15 ++
 target/riscv/cpu_bits.h                       |  17 +++
 target/riscv/cpu_cfg.h                        |   2 +
 target/riscv/cpu_helper.c                     | 140 +++++++++++++++++-
 target/riscv/cpu_user.h                       |   1 +
 target/riscv/csr.c                            |  84 +++++++++++
 target/riscv/insn16.decode                    |   4 +
 target/riscv/insn32.decode                    |  26 +++-
 target/riscv/insn_trans/trans_rva.c.inc       |  41 +++++
 target/riscv/insn_trans/trans_rvi.c.inc       |  55 +++++++
 target/riscv/insn_trans/trans_rvzicfiss.c.inc |  73 +++++++++
 target/riscv/internals.h                      |   3 +
 target/riscv/op_helper.c                      |  18 +++
 target/riscv/pmp.c                            |   5 +
 target/riscv/pmp.h                            |   3 +-
 target/riscv/tcg/tcg-cpu.c                    |  24 +++
 target/riscv/translate.c                      |  30 +++-
 20 files changed, 625 insertions(+), 14 deletions(-)
 create mode 100644 target/riscv/insn_trans/trans_rvzicfiss.c.inc

-- 
2.44.0