[v3] riscv: RVA22U64 profile support

[PATCH v3 0/6] riscv: RVA22U64 profile support

Daniel Henrique Barboza posted 6 patches 6 months, 2 weeks ago

Diff against v1 v2
Download series mbox

Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20231020223951.357513-1-dbarboza@ventanamicro.com

Maintainers: Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Weiwei Li <liweiwei@iscas.ac.cn>, Daniel Henrique Barboza <dbarboza@ventanamicro.com>, Liu Zhiwei <zhiwei_liu@linux.alibaba.com>

target/riscv/cpu.c         |  20 +++++++
target/riscv/cpu.h         |  12 ++++
target/riscv/kvm/kvm-cpu.c |   7 ++-
target/riscv/tcg/tcg-cpu.c | 118 ++++++++++++++++++++++++++++++++-----
4 files changed, 142 insertions(+), 15 deletions(-)

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[PATCH v3 0/6] riscv: RVA22U64 profile support

Posted by Daniel Henrique Barboza 6 months, 2 weeks ago

Based-on: 20231017221226.136764-1-dbarboza@ventanamicro.com
("[PATCH v2 0/6] riscv: zicntr/zihpm flags and disable support")

Hi,

The most notable change in this new version is that we're back to
enabling/disabling profile extensions during the property set()
callback, instead of doing an extra step during realize(), to give more
predictability on how profiles can interact with each other.

In the previous version profiles would be committed based on a fixed
internal order. This time they'll be evaluated via the common
left-to-right ordering we're used to in QEMU. This means that these
two configurations are different:

-cpu rv64,profileA=true,profileB=false
"enable all mandatory extensions of profile A, then disable all
mandatory extensions of profile B"

-cpu rv64,profileB=false,profileA=true
"disable all mandatory extensions of profile B, then enable all
mandatory extensions of profile A"

We're also adding an user warning if a profile is disabled. Between
implementing profile disablement (disable all its mandatory extensions)
versus not implementing it and having a flag that does nothing if the
user set it to 'off', we're choosing the least of two ills with the
former. However, given that it is a very niche feature that is hard to
use it right and very easy to do something silly, an user warning is
appropriate.

Series is based on top of the zicntr/zihpm implementation series since
they're both part of the rva22u64 profile.

Patches missing acks: 3, 6

Changes from v2:
- patches 1 and 2 from v2: moved to a separated series
- patches 6, 9 and 10 from v2: dropped
- patch 3:
  - use the set() callback to enable/disable mandatory profile
    extensions
- patch 6:
   - handle profile MISA bits in the profile set() callback
- v2 link: https://lore.kernel.org/qemu-riscv/20231006132134.1135297-1-dbarboza@ventanamicro.com/


Daniel Henrique Barboza (6):
  target/riscv: add rva22u64 profile definition
  target/riscv/kvm: add 'rva22u64' flag as unavailable
  target/riscv/tcg: add user flag for profile support
  target/riscv/tcg: add MISA user options hash
  target/riscv/tcg: add riscv_cpu_write_misa_bit()
  target/riscv/tcg: handle profile MISA bits

 target/riscv/cpu.c         |  20 +++++++
 target/riscv/cpu.h         |  12 ++++
 target/riscv/kvm/kvm-cpu.c |   7 ++-
 target/riscv/tcg/tcg-cpu.c | 118 ++++++++++++++++++++++++++++++++-----
 4 files changed, 142 insertions(+), 15 deletions(-)

-- 
2.41.0