Re: [PATCH 0/2] target/s390x: Emulate CVDG

[Thomas Huth]

On 25/01/2024 13.47, Ilya Leoshkevich wrote:
> On Thu, 2024-01-18 at 18:28 +0100, Thomas Huth wrote:
> > On 15/01/2024 21.21, Ilya Leoshkevich wrote:
> > > Hi,
> > >
> > > Ido reported that we are missing the CVDG emulation (which is very
> > > similar to the existing CVD emulation). This series adds it along
> > > with a test.
> >
> > Just FYI, your patch made me curious which other instructions we
> > still might
> > be missing from chapter 7 in the Principles of Operation... with some
> > shell
> > scripting and manual fiddling, I ended up with this list:
> >
> > 0C      BRANCH AND SAVE AND SET MODE            BASSM
> > 0B      BRANCH AND SET MODE                     BSM
> > B21A    COMPARE AND FORM CODEWORD               CFC
> > B257    COMPARE UNTIL SUBSTRING EQUAL           CUSE
> > B263    COMPRESSION CALL                        CMPSC
> > 4F      CONVERT TO BINARY (32)                  CVB
> > E306    CONVERT TO BINARY (32)                  CVBY
> > E30E    CONVERT TO BINARY (64)                  CVBG
> > B24D    COPY ACCESS                             CPYA
> > EF      LOAD MULTIPLE DISJOINT                  LMD
> > EE      PERFORM LOCKED OPERATION                PLO
> > B9BF    TRANSLATE AND TEST EXTENDED             TRTE
> > B9BD    TRANSLATE AND TEST REVERSE EXTENDED     TRTRE
> > 0102    UPDATE TREE                             UPT
> >
> > There are some additional ones from the "Guarded-Storage Facility"
> > and the
> > "Transactional-Execution Facility", but these are optional AFAIK.
> >
> > Some of these (like UPT) really look like sins from the CISC past, I
> > guess
> > we'll never need them for running Linux guests :-)
> >
> >    Thomas
>
> Thanks, I'll append this to my TODO list. At least for CVB* there seems
> to exist an unfinished patch on the list [1].
>
> [1]
> https://lore.kernel.org/qemu-devel/20180821025104.19604-8-pavel.zbitskiy@gmail.com/

Oh, interesting, there was even a v4 that fixed the review feedback:

https://lore.kernel.org/qemu-devel/20180822144039.5796-4-pavel.zbitskiy@gmail.com/

But it seems like this had fallen through the cracks :-(

Maybe we can re-activate it now...

 Thomas