[PATCH v20 16/20] s390/vfio-ap: sysfs attribute to display the guest's matrix

From: Tony Krowiak
Date: Tue Jun 21 2022 - 11:52:52 EST


The matrix of adapters and domains configured in a guest's APCB may
differ from the matrix of adapters and domains assigned to the matrix mdev,
so this patch introduces a sysfs attribute to display the matrix of
adapters and domains that are or will be assigned to the APCB of a guest
that is or will be using the matrix mdev. For a matrix mdev denoted by
$uuid, the guest matrix can be displayed as follows:

cat /sys/devices/vfio_ap/matrix/$uuid/guest_matrix

Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
Reviewed-by: Jason J. Herne <jjherne@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 48 ++++++++++++++++++++++---------
1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index d6f60072c63f..41fc2072a77b 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1422,28 +1422,24 @@ static ssize_t control_domains_show(struct device *dev,
}
static DEVICE_ATTR_RO(control_domains);

-static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
- char *buf)
+static ssize_t vfio_ap_mdev_matrix_show(struct ap_matrix *matrix, char *buf)
{
- struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
char *bufpos = buf;
unsigned long apid;
unsigned long apqi;
unsigned long apid1;
unsigned long apqi1;
- unsigned long napm_bits = matrix_mdev->matrix.apm_max + 1;
- unsigned long naqm_bits = matrix_mdev->matrix.aqm_max + 1;
+ unsigned long napm_bits = matrix->apm_max + 1;
+ unsigned long naqm_bits = matrix->aqm_max + 1;
int nchars = 0;
int n;

- apid1 = find_first_bit_inv(matrix_mdev->matrix.apm, napm_bits);
- apqi1 = find_first_bit_inv(matrix_mdev->matrix.aqm, naqm_bits);
-
- mutex_lock(&matrix_dev->mdevs_lock);
+ apid1 = find_first_bit_inv(matrix->apm, napm_bits);
+ apqi1 = find_first_bit_inv(matrix->aqm, naqm_bits);

if ((apid1 < napm_bits) && (apqi1 < naqm_bits)) {
- for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm_bits) {
- for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
+ for_each_set_bit_inv(apid, matrix->apm, napm_bits) {
+ for_each_set_bit_inv(apqi, matrix->aqm,
naqm_bits) {
n = sprintf(bufpos, "%02lx.%04lx\n", apid,
apqi);
@@ -1452,25 +1448,50 @@ static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
}
}
} else if (apid1 < napm_bits) {
- for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm_bits) {
+ for_each_set_bit_inv(apid, matrix->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->matrix.aqm, naqm_bits) {
+ for_each_set_bit_inv(apqi, matrix->aqm, naqm_bits) {
n = sprintf(bufpos, ".%04lx\n", apqi);
bufpos += n;
nchars += n;
}
}

+ return nchars;
+}
+
+static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t nchars;
+ struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
+
+ mutex_lock(&matrix_dev->mdevs_lock);
+ nchars = vfio_ap_mdev_matrix_show(&matrix_mdev->matrix, buf);
mutex_unlock(&matrix_dev->mdevs_lock);

return nchars;
}
static DEVICE_ATTR_RO(matrix);

+static ssize_t guest_matrix_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t nchars;
+ struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
+
+ mutex_lock(&matrix_dev->mdevs_lock);
+ nchars = vfio_ap_mdev_matrix_show(&matrix_mdev->shadow_apcb, buf);
+ mutex_unlock(&matrix_dev->mdevs_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,
@@ -1480,6 +1501,7 @@ 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,
};

--
2.35.3