Re: [Qemu-devel] [PATCH 0/7] s390x/pci: Improve zPCI to cover more cases

[Cornelia Huck <cohuck@redhat.com>]

On Tue, 7 Nov 2017 18:50:10 +0100
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> On 11/07/2017 06:31 PM, Cornelia Huck wrote:
> > On Tue,  7 Nov 2017 18:24:32 +0100
> > Pierre Morel <pmorel@linux.vnet.ibm.com> wrote:
> >   
> >> Right now the PCI support is very limited (e.g. pass through of a
> >> host vfio device)
> >> To enable features like virtio-pci several modifications needs to be
> >> done.
> >>
> >> Virtio-PCI uses subregions, which may eventually be discontinuous
> >> inside bars instead of a single flat region.
> >> The address offset being formerly calculated from the BAR base address
> >> must be adapted to the subregions instead of to the single region.
> >>
> >> This patch provides the new calculation for the three kind of BAR
> >> access, zPCI STORE, zPCI LOAD and zPCI STORE BLOCK.
> >>
> >> We use the opportunity to
> >>  - enhance the fault detection for zPCI STORE and LOAD,
> >>  - enhance the fault detection and to provide the maximum STORE BLOCK
> >>    block size, maxstbl, for zPCI STORE BLOCK
> >>  - factor out part of the code used to calculate the offset and
> >>    access the BARs,
> >>  - factor out the code for endianess conversion.  
> > 
> > Will look at this later. Just a quick question: What kind of further
> > functionality is enabled by this? E.g., I can attach a virtio-net-pci
> > device right now, does this enable more virtio devices?  
> 
> You can attach a virtio-net-pci today, with these patches it now starts to work ;-)

Yes, that's definitely an improvement ;)

> In essence to me this all looks like a bugfix (a big one though)

I'll look at it, but it probably is too big for 2.11.

> 
> >   
> >>
> >>
> >> Pierre Morel (7):
> >>   s390x/pci: factor out endianess conversion
> >>   s390x/pci: rework PCI STORE
> >>   s390x/pci: rework PCI LOAD
> >>   s390x/pci: rework PCI STORE BLOCK
> >>   s390x/pci: move the memory region read from pcilg
> >>   s390x/pci: move the memory region write from pcistg
> >>   s390x/pci: search for subregion inside the BARs
> >>
> >>  hw/s390x/s390-pci-bus.h  |   1 +
> >>  hw/s390x/s390-pci-inst.c | 250 ++++++++++++++++++++++++++++-------------------
> >>  hw/s390x/s390-pci-inst.h |   2 +-
> >>  3 files changed, 153 insertions(+), 100 deletions(-)
> >>  
> >   
>