Re: [PATCH v2 0/9] s390x/pci: zPCI interpretation support

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Jan 14, 2022 at 03:38:40PM -0500, Matthew Rosato wrote:
> For QEMU, the majority of the work in enabling instruction interpretation
> is handled via new VFIO ioctls to SET the appropriate interpretation and
> interrupt forwarding modes, and to GET the function handle to use for
> interpretive execution.  
> 
> This series implements these new ioctls, as well as adding a new, optional
> 'intercept' parameter to zpci to request interpretation support not be used
> as well as an 'intassist' parameter to determine whether or not the
> firmware assist will be used for interrupt delivery or whether the host
> will be responsible for delivering all interrupts.
> 
> The ZPCI_INTERP CPU feature is added beginning with the z14 model to
> enable this support.
> 
> As a consequence of implementing zPCI interpretation, ISM devices now
> become eligible for passthrough (but only when zPCI interpretation is
> available).
> 
> >From the perspective of guest configuration, you passthrough zPCI devices
> in the same manner as before, with intepretation support being used by
> default if available in kernel+qemu.
> 
> Associated kernel series:
> https://lore.kernel.org/kvm/20220114203145.242984-1-mjrosato@linux.ibm.com/

I took a quick look and don't see much to object to, but
I don't know much about the topic either.

Acked-by: Michael S. Tsirkin <mst@redhat.com>

Pls use the s390 tree for this.

> Changes v1->v2:
> 
> - Update kernel headers sync                                                    
> - Drop some pre-req patches that are now merged                                 
> - Add some R-bs (Thanks!)                                                       
> - fence FEAT_ZPCI_INTERP for QEMU 6.2 and older (Christian)                     
> - switch from container_of to VFIO_PCI and drop asserts (Thomas)                
> - re-arrange g_autofree so we malloc at time of declaration (Thomas) 
> 
> Matthew Rosato (9):
>   Update linux headers
>   target/s390x: add zpci-interp to cpu models
>   fixup: force interp off for QEMU machine 6.2 and older
>   s390x/pci: enable for load/store intepretation
>   s390x/pci: don't fence interpreted devices without MSI-X
>   s390x/pci: enable adapter event notification for interpreted devices
>   s390x/pci: use I/O Address Translation assist when interpreting
>   s390x/pci: use dtsm provided from vfio capabilities for interpreted
>     devices
>   s390x/pci: let intercept devices have separate PCI groups
> 
>  hw/s390x/s390-pci-bus.c                       | 121 ++++++++++-
>  hw/s390x/s390-pci-inst.c                      | 168 ++++++++++++++-
>  hw/s390x/s390-pci-vfio.c                      | 204 +++++++++++++++++-
>  hw/s390x/s390-virtio-ccw.c                    |   1 +
>  include/hw/s390x/s390-pci-bus.h               |   8 +-
>  include/hw/s390x/s390-pci-inst.h              |   2 +-
>  include/hw/s390x/s390-pci-vfio.h              |  45 ++++
>  include/standard-headers/asm-x86/kvm_para.h   |   1 +
>  include/standard-headers/drm/drm_fourcc.h     |  11 +
>  include/standard-headers/linux/ethtool.h      |   1 +
>  include/standard-headers/linux/fuse.h         |  60 +++++-
>  include/standard-headers/linux/pci_regs.h     |   4 +
>  include/standard-headers/linux/virtio_iommu.h |   8 +-
>  linux-headers/asm-mips/unistd_n32.h           |   1 +
>  linux-headers/asm-mips/unistd_n64.h           |   1 +
>  linux-headers/asm-mips/unistd_o32.h           |   1 +
>  linux-headers/asm-powerpc/unistd_32.h         |   1 +
>  linux-headers/asm-powerpc/unistd_64.h         |   1 +
>  linux-headers/asm-s390/kvm.h                  |   1 +
>  linux-headers/asm-s390/unistd_32.h            |   1 +
>  linux-headers/asm-s390/unistd_64.h            |   1 +
>  linux-headers/linux/kvm.h                     |   1 +
>  linux-headers/linux/vfio.h                    |  22 ++
>  linux-headers/linux/vfio_zdev.h               |  51 +++++
>  target/s390x/cpu_features_def.h.inc           |   1 +
>  target/s390x/gen-features.c                   |   2 +
>  target/s390x/kvm/kvm.c                        |   1 +
>  27 files changed, 693 insertions(+), 27 deletions(-)
> 
> -- 
> 2.27.0