On Thu, Nov 23, 2023 at 12:43 AM Eric Biggers <ebiggers@xxxxxxxxxx> wrote: > > On Wed, Nov 22, 2023 at 03:58:17PM +0800, Jerry Shih wrote: > > On Nov 22, 2023, at 07:51, Eric Biggers <ebiggers@xxxxxxxxxx> wrote: > > > On Wed, Nov 01, 2023 at 09:03:33PM -0700, Eric Biggers wrote: > > >> > > >> It would be nice to use a real assembler, so that people won't have to worry > > >> about potential mistakes or inconsistencies in the perl-based "assembler". Also > > >> keep in mind that if we allow people to compile this code without the real > > >> assembler support from the beginning, it might end up staying that way for quite > > >> a while in order to avoid breaking the build for people. > > >> > > >> Ultimately it's up to you though; I think that you and others who have been > > >> working on RISC-V crypto can make the best decision about what to do here. I > > >> also don't want this patchset to be delayed waiting for other projects, so maybe > > >> that indeed means the perl-based "assembler" needs to be used for now. > > > > > > Just wanted to bump up this discussion again. In binutils, the vector crypto > > > v1.0.0 support was released 4 months ago in 2.41. See the NEWS file at > > > https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob_plain;f=binutils/NEWS;hb=refs/heads/binutils-2_41-branch > > > > > > * The RISC-V port now supports the following new standard extensions: > > > - Zicond (conditional zero instructions) > > > - Zfa (additional floating-point instructions) > > > - Zvbb, Zvbc, Zvkg, Zvkned, Zvknh[ab], Zvksed, Zvksh, Zvkn, Zvknc, Zvkng, > > > Zvks, Zvksc, Zvkg, Zvkt (vector crypto instructions) > > > > > > That's every extension listed in the vector crypto v1.0.0 specification > > > (https://github.com/riscv/riscv-crypto/releases/download/v1.0.0/riscv-crypto-spec-vector.pdf). > > > > It doesn't fit all v1.0 spec. > > The `Zvkb` is missed in binutils. It's the subset of `Zvbb`. We needs some extra > > works if user just try to use `Zvkb`. > > https://github.com/riscv/riscv-crypto/blob/main/doc/vector/riscv-crypto-vector-zvkb.adoc > > Some crypto algorithms are already checking for `Zvkb` instead of `Zvbb`. > > Yeah, that's unfortunate that Zvkb got missed in binutils. However, since all > Zvkb instructions are part of Zvbb, which is supported, assembling Zvkb > instructions should still work --- right? Not forgotten, but the Zvkb extension did not exist when the patchset was merged. RISC-V extension support is typically merged when specifications are "frozen". This means a high bar for changes, but they are possible until the spec is ratified. Often nothing is changed until ratification, but here Zvkb has been (re-)introduced. I was not aware of this untils I read this email, so I just wrote a patch that fills the gap: https://sourceware.org/pipermail/binutils/2023-November/130762.html Thanks for reporting! BR Christoph > > > > LLVM still has the vector crypto extensions marked as "experimental" extensions. > > > However, there is an open pull request to mark them non-experimental: > > > https://github.com/llvm/llvm-project/pull/69000 > > > > > > Could we just go ahead and remove riscv.pm, develop with binutils for now, and > > > prioritize getting the LLVM support finished? > > > > Yes, we could. > > But we need to handle the extensions checking for toolchains like: > > https://github.com/torvalds/linux/commit/b6fcdb191e36f82336f9b5e126d51c02e7323480 > > I could do that, but I think I need some times to test the builds. And it will introduce > > more dependency patch which is not related to actual crypto algorithms and the > > gluing code in kernel. I will send another patch for toolchain part after the v2 patch. > > And I am working for v2 patch with your new review comments. The v2 will still > > use `perlasm`. > > Note that perlasm (.pl) vs assembly (.S), and ".inst" vs real assembler > instructions, are actually separate concerns. We could use real assembler > instructions while still using perlasm. Or we could use assembly while still > using macros that generate the instructions as .inst. > > My preference is indeed both: assembly (.S) with real assembler instructions. > That would keep things more straightforward. > > We do not necessarily need to do both before merging the code, though. It will > be beneficial to get this code merged sooner rather than later, so that other > people can work on improving it. > > I would prioritize the change to use real assembler instructions. I do think > it's worth thinking about getting that change in from the beginning, so that the > toolchain prerequisites are properly in place from the beginning and people can > properly account for them and prioritize the toolchain work as needed. > > - Eric
