[PATCH v8 0/4] QEMU RISC-V nested virtualization fixes

[Anup Patel <apatel@ventanamicro.com>]

This series does fixes and improvements to have nested virtualization
on QEMU RISC-V.

These patches can also be found in riscv_nested_fixes_v8 branch at:
https://github.com/avpatel/qemu.git

The RISC-V nested virtualization was tested on QEMU RISC-V using
Xvisor RISC-V which has required hypervisor support to run another
hypervisor as Guest/VM.

Changes since 7:
 - Improve tinst "Addr. Offset" in PATCH3

Changes since v6:
 - Droppred original PATCH1 and PATCH2 since these are already merged
 - Added PATCH1 to revert dummy mcountinhibit CSR
 - Added PATCH2 to fix minimum priv spec version for mcountinhibit CSR
 - Fixed checkpatch error in PATCH3
 - Fixed compile error in PATCH4

Changes since v5:
 - Correctly set "Addr. Offset" for misaligned load/store traps in PATCH3
 - Use offsetof() instead of pointer in PATCH4

Changes since v4:
 - Updated commit description in PATCH1, PATCH2, and PATCH4
 - Use "const" for local array in PATCH5

Changes since v3:
 - Updated PATCH3 to set special pseudoinstructions in htinst for
   guest page faults which result due to VS-stage page table walks
 - Updated warning message in PATCH4

Changes since v2:
 - Dropped the patch which are already in Alistair's next branch
 - Set "Addr. Offset" in the transformed instruction for PATCH3
 - Print warning in riscv_cpu_realize() if we are disabling an
   extension due to privilege spec verions mismatch for PATCH4

Changes since v1:
 - Set write_gva to env->two_stage_lookup which ensures that for
   HS-mode to HS-mode trap write_gva is true only for HLV/HSV
   instructions
 - Included "[PATCH 0/3] QEMU RISC-V priv spec version fixes"
   patches in this series for easy review
 - Re-worked PATCH7 to force disable extensions if required
   priv spec version is not staisfied
 - Added new PATCH8 to fix "aia=aplic-imsic" mode of virt machine

Anup Patel (4):
  Revert "target/riscv: Add dummy mcountinhibit CSR for priv spec v1.11
    or higher"
  target/riscv: Set minumum priv spec version for mcountinhibit
  target/riscv: Update [m|h]tinst CSR in riscv_cpu_do_interrupt()
  target/riscv: Force disable extensions if priv spec version does not
    match

 target/riscv/cpu.c        | 150 +++++++++++++++---------
 target/riscv/cpu.h        |   5 +
 target/riscv/cpu_bits.h   |   3 -
 target/riscv/cpu_helper.c | 235 +++++++++++++++++++++++++++++++++++++-
 target/riscv/csr.c        |   4 +-
 target/riscv/instmap.h    |  45 ++++++++
 6 files changed, 374 insertions(+), 68 deletions(-)

-- 
2.34.1