Re: [qemu-s390x] [PATCH v2 4/5] s390x/vfio: ap: Introduce VFIO AP device

[Tony Krowiak]

On 02/27/2018 12:04 PM, Cornelia Huck wrote:
> On Tue, 27 Feb 2018 10:44:18 -0500
> Tony Krowiak <address@hidden> wrote:
>
> > Introduces a VFIO based AP device. The device is defined via
> > the QEMU command line by specifying:
> >
> >      -device vfio-ap,sysfsdev=<path-to-mediated-matrix-device>
> >
> > The mediated matrix device is created by the VFIO AP device
> > driver by writing a UUID to a sysfs attribute file (see
> > docs/vfio-ap.txt). The mediated matrix device will be named
> > after the UUID. Symbolic links to the $uuid are created in
> > many places, so the path to the mediated matrix device $uuid
> > can be specified in any of the following ways:
> >
> > /sys/devices/vfio_ap/matrix/$uuid
> > /sys/devices/vfio_ap/matrix/mdev_supported_types/vfio_ap-passthrough/devices/$uuid
> > /sys/bus/mdev/devices/$uuid
> > /sys/bus/mdev/drivers/vfio_mdev/$uuid
> >
> > When the vfio-ap device is realized, it acquires and opens the
> > VFIO iommu group to which the mediated matrix device is
> > bound. This causes a VFIO group notification event to be
> > signaled. The vfio_ap device driver's group notification
> > handler will get called at which time the device driver
> > will configure the the AP devices to which the guest will
> > be granted access.
> >
> > Signed-off-by: Tony Krowiak <address@hidden>
> > ---
> >   default-configs/s390x-softmmu.mak |    1 +
> >   hw/vfio/Makefile.objs             |    1 +
> >   hw/vfio/ap.c                      |  167 +++++++++++++++++++++++++++++++++++++
> >   include/hw/vfio/vfio-common.h     |    1 +
> >   4 files changed, 170 insertions(+), 0 deletions(-)
> >   create mode 100644 hw/vfio/ap.c
> >
> > diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
> > new file mode 100644
> > index 0000000..8aa5221
> > --- /dev/null
> > +++ b/hw/vfio/ap.c
> > @@ -0,0 +1,167 @@
> > +/*
> > + * VFIO based AP matrix device assignment
> > + *
> > + * Copyright 2017 IBM Corp.
> Happy new year?
Happy New Year to you too ;)
> [Also the other new files, here and in the Linux part.]
I'll fix this in all new files in the patch series.
> > + * Author(s): Tony Krowiak <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or(at
> > + * your option) any version. See the COPYING file in the top-level
> That probably should be "any later version" (I'm not even sure what GPL
> v1 says :)
Will do.
> And I just noticed that the vfio-ccw code has the same problem...
I'm not fixing those :)
> > + * directory.
> > + */
> > +
> > +#include <linux/vfio.h>
> > +#include <sys/ioctl.h>
> > +#include "qemu/osdep.h"
> > +#include "qapi/error.h"
> > +#include "hw/sysbus.h"
> > +#include "hw/vfio/vfio.h"
> > +#include "hw/vfio/vfio-common.h"
> > +#include "hw/s390x/ap-device.h"
> > +#include "qemu/error-report.h"
> > +#include "qemu/queue.h"
> > +
> > +#define VFIO_AP_DEVICE_TYPE      "vfio-ap"
> > +#define AP_SYSFSDEV_PROP_NAME    "sysfsdev"
> Using a #define for a property name seems unusual (and I think it
> decreases readability).
I'll remove it
> Otherwise, looks fine (on first read-through).