[PATCH v11 07/14] s390/vfio-ap: sysfs attribute to display the guest's matrix

From: Tony Krowiak
Date: Thu Oct 22 2020 - 13:13:41 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 a guest
using the matrix mdev. For a matrix mdev denoted by $uuid, the crycb for a
guest using the matrix mdev can be displayed as follows:

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

If a guest is not using the matrix mdev at the time the crycb is displayed,
an error (ENODEV) will be returned.

Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 54 +++++++++++++++++++++++--------
1 file changed, 40 insertions(+), 14 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 9791761aa7fd..7bad70d7bcef 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1073,29 +1073,24 @@ 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 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->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->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);
@@ -1104,25 +1099,55 @@ 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 mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ mutex_lock(&matrix_dev->lock);
+ nchars = vfio_ap_mdev_matrix_show(&matrix_mdev->matrix, buf);
mutex_unlock(&matrix_dev->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 mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ if (!vfio_ap_mdev_has_crycb(matrix_mdev))
+ return -ENODEV;
+
+ mutex_lock(&matrix_dev->lock);
+ nchars = vfio_ap_mdev_matrix_show(&matrix_mdev->shadow_apcb, buf);
+ 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,
@@ -1132,6 +1157,7 @@ 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,
};

--
2.21.1