Re: [PATCH v9 0/6] Pointer Masking update for Zjpm v1.0

[Alistair Francis]

On Mon, May 13, 2024 at 9:05 PM Alexey Baturo <baturo.alexey@gmail.com> wrote:
>
> Hi,
>
> > Hi, any change from v0.8 to v1.0?
> Not in the patches that were sent. I'd still suggest applying a step-by-step 
> approach with cleaning up old code and establishing the new mechanisms first 
> and then updating the code to match the spec 100%. Also I heard Martin has 
> some arch compliance tests for J-ext somewhere.

The cover letter says that this implements version 1.0 of the spec,
this sounds like it doesn't.

Also, it's better to make the changes on top of the current code.
Instead of constantly removing and re-adding the code. Which is then
hard to review. Especially as I'm guessing there isn't a huge
difference between v0.8 and v1.0.

> @Alistair Francis @liwei does this approach sound reasonable to you?
>
> >Also, this needs another rebase
> Sure, no problem at all. I'll rebase and re-send them later today.

Thanks. Can you be very clear which version of the spec you have
developed and tested against as well.

Alistair

>
> Thanks
>
> пн, 13 мая 2024 г. в 13:25, Alistair Francis <alistair23@gmail.com>:
>>
>> On Sun, May 12, 2024 at 12:44 AM liwei <liwei1518@gmail.com> wrote:
>> >
>> >
>> > On 2024/5/11 18:10, Alexey Baturo wrote:
>> > > From: Alexey Baturo <baturo.alexey@gmail.com>
>> > >
>> > > Hi,
>> > >
>> > > It looks like Pointer Masking spec has reached v1.0 and been frozen,
>> > > rebasing on riscv-to-apply.next branch and resubmitting patches.
>> >
>> > Hi, any change from v0.8 to v1.0?
>>
>> Good question.
>>
>> Also, this needs another rebase. Sorry, it seems to always have
>> conflicts. If you re-send I'll apply it right away
>>
>> Alistair
>>
>> >
>> > Regards,
>> >
>> > Weiwei Li
>> >
>> > >
>> > > Thanks.
>> > >
>> > > [v8]:
>> > > Rebasing patches on current qemu branch and resubmitting them.
>> > >
>> > >
>> > > [v7]:
>> > > I'm terribly sorry, but previous rebase went wrong and somehow I missed 
>> > > it.
>> > > This time I double-checked rebased version.
>> > > This patch series is properly rebased on 
>> > > https://github.com/alistair23/qemu/tree/riscv-to-apply.next
>> > >
>> > > [v6]:
>> > > This patch series is rebased on 
>> > > https://github.com/alistair23/qemu/tree/riscv-to-apply.next
>> > >
>> > > [v5]:
>> > > This patch series targets Zjpm v0.8 extension.
>> > > The spec itself could be found here: 
>> > > https://github.com/riscv/riscv-j-extension/blob/8088461d8d66a7676872b61c908cbeb7cf5c5d1d/zjpm-spec.pdf
>> > > This patch series is updated after the suggested comments:
>> > > - add "x-" to the extension names to indicate experimental
>> > >
>> > > [v4]:
>> > > Patch series updated after the suggested comments:
>> > > - removed J-letter extension as it's unused
>> > > - renamed and fixed function to detect if address should be sign-extended
>> > > - zeroed unused context variables and moved computation logic to another 
>> > > patch
>> > > - bumped pointer masking version_id and minimum_version_id by 1
>> > >
>> > > [v3]:
>> > > There patches are updated after Richard's comments:
>> > > - moved new tb flags to the end
>> > > - used tcg_gen_(s)extract to get the final address
>> > > - properly handle CONFIG_USER_ONLY
>> > >
>> > > [v2]:
>> > > As per Richard's suggestion I made pmm field part of tb_flags.
>> > > It allowed to get rid of global variable to store pmlen.
>> > > Also it allowed to simplify all the machinery around it.
>> > >
>> > > [v1]:
>> > > It looks like Zjpm v0.8 is almost frozen and we don't expect it change 
>> > > drastically anymore.
>> > > Compared to the original implementation with explicit base and mask 
>> > > CSRs, we now only have
>> > > several fixed options for number of masked bits which are set using 
>> > > existing CSRs.
>> > > The changes have been tested with handwritten assembly tests and LLVM 
>> > > HWASAN
>> > > test suite.
>> > >
>> > > Alexey Baturo (6):
>> > >    target/riscv: Remove obsolete pointer masking  extension code.
>> > >    target/riscv: Add new CSR fields for S{sn,mn,m}pm extensions as part
>> > >      of Zjpm v0.8
>> > >    target/riscv: Add helper functions to calculate current number of
>> > >      masked bits for pointer masking
>> > >    target/riscv: Add pointer masking tb flags
>> > >    target/riscv: Update address modify functions to take into account
>> > >      pointer masking
>> > >    target/riscv: Enable updates for pointer masking variables and thus
>> > >      enable pointer masking extension
>> > >
>> > >   target/riscv/cpu.c           |  21 +--
>> > >   target/riscv/cpu.h           |  46 +++--
>> > >   target/riscv/cpu_bits.h      |  90 +---------
>> > >   target/riscv/cpu_cfg.h       |   3 +
>> > >   target/riscv/cpu_helper.c    |  97 +++++-----
>> > >   target/riscv/csr.c           | 337 ++---------------------------------
>> > >   target/riscv/machine.c       |  20 +--
>> > >   target/riscv/pmp.c           |  13 +-
>> > >   target/riscv/pmp.h           |  11 +-
>> > >   target/riscv/tcg/tcg-cpu.c   |   5 +-
>> > >   target/riscv/translate.c     |  46 ++---
>> > >   target/riscv/vector_helper.c |  15 +-
>> > >   12 files changed, 158 insertions(+), 546 deletions(-)
>> > >
>> >