[PATCH v2 2/8] s390: vfio-ap: sysfs interface to display guest CRYCB

[Tony Krowiak <akrowiak@xxxxxxxxxxxxx>]

Introduces a sysfs interface on the matrix mdev device to display the
contents of the shadow of the guest's CRYCB

Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
---
 drivers/s390/crypto/vfio_ap_ops.c | 58 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index b0453e6c20d0..eae4ee24460a 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -750,6 +750,63 @@ static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(matrix);
 
+static ssize_t guest_matrix_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct mdev_device *mdev = mdev_from_dev(dev);
+	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+	char *bufpos = buf;
+	unsigned long apid;
+	unsigned long apqi;
+	unsigned long apid1;
+	unsigned long apqi1;
+	unsigned long napm_bits = matrix_mdev->shadow_crycb->apm_max + 1;
+	unsigned long naqm_bits = matrix_mdev->shadow_crycb->aqm_max + 1;
+	int nchars = 0;
+	int n;
+
+	if (!matrix_mdev->shadow_crycb)
+		return -ENODEV;
+
+	apid1 = find_first_bit_inv(matrix_mdev->shadow_crycb->apm, napm_bits);
+	apqi1 = find_first_bit_inv(matrix_mdev->shadow_crycb->aqm, naqm_bits);
+
+	mutex_lock(&matrix_dev->lock);
+
+	if ((apid1 < napm_bits) && (apqi1 < naqm_bits)) {
+		for_each_set_bit_inv(apid, matrix_mdev->shadow_crycb->apm,
+				     napm_bits) {
+			for_each_set_bit_inv(apqi,
+					     matrix_mdev->shadow_crycb->aqm,
+					     naqm_bits) {
+				n = sprintf(bufpos, "%02lx.%04lx\n", apid,
+					    apqi);
+				bufpos += n;
+				nchars += n;
+			}
+		}
+	} else if (apid1 < napm_bits) {
+		for_each_set_bit_inv(apid, matrix_mdev->shadow_crycb->apm,
+				     napm_bits) {
+			n = sprintf(bufpos, "%02lx.\n", apid);
+			bufpos += n;
+			nchars += n;
+		}
+	} else if (apqi1 < naqm_bits) {
+		for_each_set_bit_inv(apqi, matrix_mdev->shadow_crycb->aqm,
+				     naqm_bits) {
+			n = sprintf(bufpos, ".%04lx\n", apqi);
+			bufpos += n;
+			nchars += n;
+		}
+	}
+
+	mutex_unlock(&matrix_dev->lock);
+
+	return nchars;
+}
+static DEVICE_ATTR_RO(guest_matrix);
+
 static struct attribute *vfio_ap_mdev_attrs[] = {
 	&dev_attr_assign_adapter.attr,
 	&dev_attr_unassign_adapter.attr,
@@ -759,6 +816,7 @@ static struct attribute *vfio_ap_mdev_attrs[] = {
 	&dev_attr_unassign_control_domain.attr,
 	&dev_attr_control_domains.attr,
 	&dev_attr_matrix.attr,
+	&dev_attr_guest_matrix.attr,
 	NULL,
 };
 
-- 
2.7.4