On 11/7/23 03:07, Harald Freudenberger wrote:

On 2023-11-06 17:03, Tony Krowiak wrote:

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PING This patch is pretty straight forward, does anyone see a reason why this shouldn't be integrated?

On 10/20/23 16:48, Tony Krowiak wrote:

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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 Fixes: f139862b92cf ("s390/vfio-ap: add status attribute to AP queue device's sysfs dir") Cc: stable@vger.kernel.org

---

drivers/s390/crypto/vfio_ap_ops.c | 7 ++++++-   1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 4db538a55192..871c14a6921f 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);   @@ -1984,7 +1985,11 @@ static ssize_t status_show(struct device *dev,       matrix_mdev = vfio_ap_mdev_for_queue(q);         if (matrix_mdev) { -        if (matrix_mdev->kvm) +        apid = AP_QID_CARD(q->apqn); +        apqi = AP_QID_QUEUE(q->apqn); +        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

I can give you an Acked-by: Harald Freudenberger freude@linux.ibm.com for this. Your explanation sounds sane to me and fixes a wrong display. However, I am not familiar with the code so, I can't tell if that's correct. Just a remark: How can it happen that one queue is not bound to the vfio dd? Didn't we actively remove the unbind possibility from the sysfs for devices assigned to the vfio dd?

A device bound to the vfio_ap device driver can be manually unbound; however, it can not be unbound by the AP bus via a change to the apmask/aqmask attributes if it is assigned to a mediated device.

At one point I wanted to remove the unbind sysfs attribute, but as I recall I was talked out of it.