[PATCH 1/1] lib: sbi_misaligned_ldst: Add handling of vector load/store

[Nylon Chen]

Hi all,

This is gentle ping.

Is there any problem with this patch? If so, please let me know.

thanks a lot.

Nylon Chen <nylon.chen at sifive.com> 於 2024年10月31日 週四 上午11:22寫道：
>
> Nylon Chen <nylon.chen at sifive.com> 於 2024年10月18日 週五 上午10:29寫道：
> >
> > Vivian Wang <uwu at dram.page> 於 2024年10月17日 週四 上午3:34寫道：
> > >
> > > On 10/16/24 18:35, Nylon Chen wrote:
> > > > Add exception handling vector instructions from
> > > >
> > > > the vector extension to the sbi_misaligned_ldst library.
> > > >
> > > > This implementation references the misaligned_vec_ldst
> > > > implementation in the riscv-pk project.
> > > >
> > > > Co-developed-by: Zong Li <zong.li at sifive.com>
> > > > Signed-off-by: Zong Li <zong.li at sifive.com>
> > > > Signed-off-by: Nylon Chen <nylon.chen at sifive.com>
> > > > Reviewed-by: Andy Chiu <andy.chiu at sifive.com>
> > > > ---
> > > >  Makefile                     |  15 +-
> > > >  include/sbi/riscv_encoding.h | 385 ++++++++++++++++++++++++++++++++++-
> > > >  include/sbi/sbi_trap_ldst.h  |   9 +
> > > >  lib/sbi/Kconfig              |   4 +
> > > >  lib/sbi/objects.mk           |   1 +
> > > >  lib/sbi/sbi_trap_ldst.c      |  23 ++-
> > > >  lib/sbi/sbi_trap_v_ldst.c    | 341 +++++++++++++++++++++++++++++++
> > > >  7 files changed, 766 insertions(+), 12 deletions(-)
> > > >  create mode 100644 lib/sbi/sbi_trap_v_ldst.c
> > > >
> > > > *snip*
> > >
> > Hi Vivian, Thank you for your question regarding my patch.
>
> Hi Vivian,
> > > I didn't see any mention of mstatus in the patch. Maybe I missed it but
> > > since we eventually reload mstatus, we should explicitly set mstatus.VS
> > > to "Dirty" (both bits 1) in the saved registers. See [1] for handling of
> > > mstatus.FS.
> > >
> Based on our testing and discussions, we don't need to specifically
> set the VS field in mstatus to dirty in this implementation.
>
> This is different from how the emulator handles FP operations.
>
> When it's in the emulator and uses vector-related instructions, these
> instructions will automatically set the VS field in mstatus to dirty
> at the time of execution.
>
> Thank you again for your input. Please let us know if our
> understanding is incorrect. Thank you.
> > > [1]: https://patchwork.ozlabs.org/project/opensbi/patch/20230906090114.24625-1-greentime.hu@sifive.com/
> > >
> > I appreciate your attention to detail, and I will take some time to
> > check the specifics you've mentioned. If it's right, I'll make the
> > corresponding modifications.
> >
> > Specifically, I will update the code to set mstatus explicitly.VS to
> > "Dirty" to notify the system to save the vector register state,
> > similar to how mstatus.FS.
> >
> > e.g.
> > int sbi_misaligned_v_ld/st_emulator() {
> >         SET_VS_DIRTY(regs)
> >         ...
> > }