Re: [PATCH v10 04/26] s390: vfio-ap: base implementation of VFIO AP device driver

[Tony Krowiak]

On 09/20/2018 11:31 AM, Cornelia Huck wrote:
> On Wed, 12 Sep 2018 15:42:54 -0400
> Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
>
> > From: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> >
> > Introduces a new AP device driver. This device driver
> > is built on the VFIO mediated device framework. The framework
> > provides sysfs interfaces that facilitate passthrough
> > access by guests to devices installed on the linux host.
> >
> > The VFIO AP device driver will serve two purposes:
> >
> > 1. Provide the interfaces to reserve AP devices for exclusive
> >     use by KVM guests. This is accomplished by unbinding the
> >     devices to be reserved for guest usage from the zcrypt
> >     device driver and binding them to the VFIO AP device driver.
> >
> > 2. Implements the functions, callbacks and sysfs attribute
> >     interfaces required to create one or more VFIO mediated
> >     devices each of which will be used to configure the AP
> >     matrix for a guest and serve as a file descriptor
> >     for facilitating communication between QEMU and the
> >     VFIO AP device driver.
> >
> > When the VFIO AP device driver is initialized:
> >
> > * It registers with the AP bus for control of type 10 (CEX4
> >    and newer) AP queue devices. This limitation was imposed
> >    due to:
> >
> >    1. A desire to keep the code as simple as possible;
> >
> >    2. Some older models are no longer supported by the kernel
> >       and others are getting close to end of service.
> >
> >    The probe and remove callbacks will be provided to support
> >    the binding/unbinding of AP queue devices to/from the VFIO
> >    AP device driver.
> >
> > * Creates a matrix device, /sys/devices/vfio_ap/matrix,
> >    to serve as the parent of the mediated devices created, one
> >    for each guest, and to hold the APQNs of the AP devices bound to
> >    the VFIO AP device driver.
> >
> > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> > Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
> > Tested-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
> > Tested-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
> > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Christian's S-o-b looks a bit odd here; OTOH, it's probably him anyway
> who will queue the patches in the end :)

It went in there when Christian submitted the patch series in my absence 
back in
July while I was on vacation. I wasn't aware it was in the actual commit 
message,
so it never got removed. I'll remove it if a v11 needs to be submitted.

> > ---
> >   MAINTAINERS                           |   10 +++
> >   arch/s390/Kconfig                     |   11 +++
> >   drivers/iommu/Kconfig                 |    8 ++
> >   drivers/s390/crypto/Makefile          |    4 +
> >   drivers/s390/crypto/vfio_ap_drv.c     |  134 +++++++++++++++++++++++++++++++++
> >   drivers/s390/crypto/vfio_ap_private.h |   34 ++++++++
> >   6 files changed, 201 insertions(+), 0 deletions(-)
> >   create mode 100644 drivers/s390/crypto/vfio_ap_drv.c
> >   create mode 100644 drivers/s390/crypto/vfio_ap_private.h
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>