On 04/02/2018 01:05 PM, Tony Krowiak wrote:
On 03/27/2018 08:02 AM, Cornelia Huck wrote:
On Fri, 16 Mar 2018 14:22:52 +0100
Halil Pasic <pa...@linux.vnet.ibm.com> wrote:
On 03/16/2018 11:42 AM, Pierre Morel wrote:
On 16/03/2018 00:24, Tony Krowiak 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 <akrow...@linux.vnet.ibm.com>
---
[..]
+static void vfio_ap_realize(DeviceState *dev, Error **errp)
+{
+ VFIODevice *vbasedev;
+ VFIOGroup *vfio_group;
+ APDevice *apdev = DO_UPCAST(APDevice, parent_obj, dev);
+ VFIOAPDevice *vapdev = DO_UPCAST(VFIOAPDevice, apdev, apdev);
+ char *mdevid;
+ Error *local_err = NULL;
+ int ret;
+
+ if (!s390_has_feat(S390_FEAT_AP)) {
+ error_setg(&local_err, "AP support not enabled");
+ goto out_err;
+ }
+
+ ret = kvm_s390_set_interpret_ap(1);
If we have several devices, this is called once per device.
I don't think having several of these in a single vm makes
any sense. Or does it? IMHO we should make sure there is at
most one device taking care of the crypto pass-through.
Yes, I think we should fence off adding a second device in the realize
function (probably by checking a global variable?)
I agree, will do.
In light of comments Connie made in Message ID:
<20180403113619.54ff1e18.coh...@redhat.com>, this
raises the question: What about hotplug? If we allow only one vfio_ap
device for a guest, then
there will be no hot plugging of vfio_ap devices except for the case
where no vfio_ap device is
defined for the guest at startup. The question then becomes how do we
configure (hot plug?)
additional queues for guest usage? I will have to give this some
additional thought before
committing to a solution here.
