On Sun, 15 Apr 2018 15:07:23 -0400
Tony Krowiak <akrow...@linux.vnet.ibm.com> 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>
>
> There may be only one vfio-ap device configured for a guest.
>
> 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 <akrow...@linux.vnet.ibm.com>
> ---
> default-configs/s390x-softmmu.mak | 1 +
> hw/vfio/Makefile.objs | 1 +
> hw/vfio/ap.c | 191
> +++++++++++++++++++++++++++++++++++++
> include/hw/vfio/vfio-common.h | 1 +
> 4 files changed, 194 insertions(+), 0 deletions(-)
> create mode 100644 hw/vfio/ap.c
> +static void vfio_ap_realize(DeviceState *dev, Error **errp)
> +{
> + VFIODevice *vbasedev;
> + VFIOGroup *vfio_group;
> + APDevice *apdev = DO_UPCAST(APDevice, parent_obj, dev);
> + char *mdevid;
> + Error *local_err = NULL;
> + int ret;
> +
> + /*
> + * Since a guest's matrix is configured in its entirety by the mediated
> + * matrix device and hot plug is not currently supported, there is no
> + * need to have more than one vfio-ap device. Check if a vfio-ap device
> + * has already been defined.
> + */
> + if (vfio_apdev) {
> + error_setg(&local_err, "Only one %s device is allowed",
> + VFIO_AP_DEVICE_TYPE);
> + goto out_err;
> + }
> +
> + if (!s390_has_feat(S390_FEAT_AP)) {
> + error_setg(&local_err, "AP support not enabled");
> + goto out_err;
> + }
> +
> + vfio_apdev = DO_UPCAST(VFIOAPDevice, apdev, apdev);
> +
> + vfio_group = vfio_ap_get_group(vfio_apdev, &local_err);
> + if (!vfio_group) {
> + goto out_err;
> + }
> +
> + vfio_apdev->vdev.ops = &vfio_ap_ops;
> + vfio_apdev->vdev.type = VFIO_DEVICE_TYPE_AP;
> + mdevid = basename(vfio_apdev->vdev.sysfsdev);
> + vfio_apdev->vdev.name = g_strdup_printf("%s", mdevid);
> + vfio_apdev->vdev.dev = dev;
> + QLIST_FOREACH(vbasedev, &vfio_group->device_list, next) {
> + if (strcmp(vbasedev->name, vfio_apdev->vdev.name) == 0) {
> + error_setg(&local_err,
> + "%s: AP device %s has already been realized",
> + VFIO_AP_DEVICE_TYPE, vfio_apdev->vdev.name);
> + goto out_device_err;
> + }
> + }
> +
> + ret = vfio_get_device(vfio_group, mdevid, &vfio_apdev->vdev, &local_err);
> + if (ret) {
> + goto out_device_err;
> + }
Don't you need a put somewhere to avoid memory leaks?
> +
> + return;
> +
> +
> +out_device_err:
> + vfio_put_group(vfio_group);
> +out_err:
> + vfio_apdev = NULL;
> + error_propagate(errp, local_err);
> +}
