Re: [Qemu-devel] [PATCH v2 0/3] s390x/sclp: 64 bit event masks

[Claudio Imbrenda]

On Fri, 23 Feb 2018 11:37:55 +0100
Cornelia Huck  wrote:

> On Thu, 22 Feb 2018 17:22:56 +0100
> Claudio Imbrenda  wrote:
> 
> > Until 67915de9f0383ccf4a ("s390x/event-facility: variable-length
> > event masks") we only supported 32bit sclp event masks, even though
> > the archiecture allows the guests to set up sclp event masks up to
> > 1021 bytes in length. With that patch the behaviour was almost
> > compliant, but some issues were still remaining, in particular
> > regarding the handling of selective reads and migration.
> > 
> > This patchset fixes migration and the handling of selective reads,
> > and puts in place the support for 64-bit sclp event masks
> > internally.
> > 
> > A new property of the sclp-event device switches between the 32bit
> > masks and the compliant behaviour. The property is bound to the
> > machine version, so older machines keep the old broken behaviour,
> > allowing for migration, but the default is the compliant
> > implementation.
> > 
> > Fixes: 67915de9f0383ccf4a ("s390x/event-facility: variable-length
> > event masks")
> > 
> > v1 -> v2 
> > * improved comments and patch descriptions to better explain why we
> > need this, including better description of the old broken behaviour
> > * rename SCLPEVMSK to SCLP_EVMASK to improve readability
> > * removed some unneded variable initializations
> > * fixed a pre-existing typo
> > 
> > Claudio Imbrenda (3):
> >   s390x/sclp: proper support of larger send and receive masks
> >   s390x/sclp: clean up sclp masks
> >   s390x/sclp: extend SCLP event masks to 64 bits
> > 
> >  hw/char/sclpconsole-lm.c  |   4 +-
> >  hw/char/sclpconsole.c |   4 +-
> >  hw/s390x/event-facility.c | 150
> > +++---
> > hw/s390x/s390-virtio-ccw.c|   8 +-
> > hw/s390x/sclpcpu.c|   4 +-
> > hw/s390x/sclpquiesce.c|   4 +-
> > include/hw/s390x/event-facility.h |  22 +++--- 7 files changed, 151
> > insertions(+), 45 deletions(-) 
> 
> This looks sane as far as I can see without having access to the
> documentation.
> 
> BTW, I saw you also extended the masks in the Linux (guest) code (at
> least, I see patches queued on the s390 features branch...) You also
> might want to adjust the "Linux uses 4 byte masks" comment in the code
> in the future.

will fix, so that I don't have to remember to do stuff in the future :)
 
> Before I queue this, I'd like some r-bs/a-bs by folks with access to
> the documentation.
> 

Re: [Qemu-devel] [PATCH v2 0/3] s390x/sclp: 64 bit event masks

[Cornelia Huck]

On Thu, 22 Feb 2018 17:22:56 +0100
Claudio Imbrenda  wrote:

> Until 67915de9f0383ccf4a ("s390x/event-facility: variable-length event masks")
> we only supported 32bit sclp event masks, even though the archiecture
> allows the guests to set up sclp event masks up to 1021 bytes in length.
> With that patch the behaviour was almost compliant, but some issues were
> still remaining, in particular regarding the handling of selective reads
> and migration.
> 
> This patchset fixes migration and the handling of selective reads, and
> puts in place the support for 64-bit sclp event masks internally.
> 
> A new property of the sclp-event device switches between the 32bit masks
> and the compliant behaviour. The property is bound to the machine
> version, so older machines keep the old broken behaviour, allowing for
> migration, but the default is the compliant implementation.
> 
> Fixes: 67915de9f0383ccf4a ("s390x/event-facility: variable-length event 
> masks")
> 
> v1 -> v2 
> * improved comments and patch descriptions to better explain why we need
>   this, including better description of the old broken behaviour
> * rename SCLPEVMSK to SCLP_EVMASK to improve readability
> * removed some unneded variable initializations
> * fixed a pre-existing typo
> 
> Claudio Imbrenda (3):
>   s390x/sclp: proper support of larger send and receive masks
>   s390x/sclp: clean up sclp masks
>   s390x/sclp: extend SCLP event masks to 64 bits
> 
>  hw/char/sclpconsole-lm.c  |   4 +-
>  hw/char/sclpconsole.c |   4 +-
>  hw/s390x/event-facility.c | 150 
> +++---
>  hw/s390x/s390-virtio-ccw.c|   8 +-
>  hw/s390x/sclpcpu.c|   4 +-
>  hw/s390x/sclpquiesce.c|   4 +-
>  include/hw/s390x/event-facility.h |  22 +++---
>  7 files changed, 151 insertions(+), 45 deletions(-)
> 

This looks sane as far as I can see without having access to the
documentation.

BTW, I saw you also extended the masks in the Linux (guest) code (at
least, I see patches queued on the s390 features branch...) You also
might want to adjust the "Linux uses 4 byte masks" comment in the code
in the future.

Before I queue this, I'd like some r-bs/a-bs by folks with access to
the documentation.