From: Tony Krowiak akrowiak@linux.ibm.com
[ Upstream commit a0d8f4eeb7c4ffaee21702bcc91a09b3988c5b7a ]
The 'status' attribute for AP queue devices bound to the vfio_ap device driver displays incorrect status when the mediated device is attached to a guest, but the queue device is not passed through. In the current implementation, the status displayed is 'in_use' which is not correct; it should be 'assigned'. This can happen if one of the queue devices associated with a given adapter is not bound to the vfio_ap device driver. For example:
Queues listed in /sys/bus/ap/drivers/vfio_ap: 14.0005 14.0006 14.000d 16.0006 16.000d
Queues listed in /sys/devices/vfio_ap/matrix/$UUID/matrix 14.0005 14.0006 14.000d 16.0005 16.0006 16.000d
Queues listed in /sys/devices/vfio_ap/matrix/$UUID/guest_matrix 14.0005 14.0006 14.000d
The reason no queues for adapter 0x16 are listed in the guest_matrix is because queue 16.0005 is not bound to the vfio_ap device driver, so no queue associated with the adapter is passed through to the guest; therefore, each queue device for adapter 0x16 should display 'assigned' instead of 'in_use', because those queues are not in use by a guest, but only assigned to the mediated device.
Let's check the AP configuration for the guest to determine whether a queue device is passed through before displaying a status of 'in_use'.
Signed-off-by: Tony Krowiak akrowiak@linux.ibm.com Acked-by: Halil Pasic pasic@linux.ibm.com Acked-by: Harald Freudenberger freude@linux.ibm.com Link: https://lore.kernel.org/r/20231108201135.351419-1-akrowiak@linux.ibm.com Signed-off-by: Alexander Gordeev agordeev@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/s390/crypto/vfio_ap_ops.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 4db538a55192..6e0a79086656 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -1976,6 +1976,7 @@ static ssize_t status_show(struct device *dev, { ssize_t nchars = 0; struct vfio_ap_queue *q; + unsigned long apid, apqi; struct ap_matrix_mdev *matrix_mdev; struct ap_device *apdev = to_ap_dev(dev);
@@ -1983,8 +1984,21 @@ static ssize_t status_show(struct device *dev, q = dev_get_drvdata(&apdev->device); matrix_mdev = vfio_ap_mdev_for_queue(q);
+ /* If the queue is assigned to the matrix mediated device, then + * determine whether it is passed through to a guest; otherwise, + * indicate that it is unassigned. + */ if (matrix_mdev) { - if (matrix_mdev->kvm) + apid = AP_QID_CARD(q->apqn); + apqi = AP_QID_QUEUE(q->apqn); + /* + * If the queue is passed through to the guest, then indicate + * that it is in use; otherwise, indicate that it is + * merely assigned to a matrix mediated device. + */ + if (matrix_mdev->kvm && + test_bit_inv(apid, matrix_mdev->shadow_apcb.apm) && + test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm)) nchars = scnprintf(buf, PAGE_SIZE, "%s\n", AP_QUEUE_IN_USE); else