Re: [PATCH v13 08/15] s390/vfio-ap: sysfs attribute to display the guest's matrix

On 1/11/21 5:58 PM, Halil Pasic wrote:

On Tue, 22 Dec 2020 20:15:59 -0500
Tony Krowiak [off-list ref] wrote:

quoted

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@linux.ibm.com>

Reviewed-by: Halil Pasic <pasic@linux.ibm.com>

But because vfio_ap_mdev_commit_shadow_apcb() is not used (see prev
patch) the attribute won't show the guest matrix at this point. :(

I'll move this patch following all of the filtering and hot plug
patches.

quoted

---
  drivers/s390/crypto/vfio_ap_ops.c | 51 ++++++++++++++++++++++---------
  1 file changed, 37 insertions(+), 14 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 44b3a81cadfb..1b1d5975ee0e 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c

@@ -894,29 +894,24 @@ 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);

@@ -925,25 +920,52 @@ 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);
+
+	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,

@@ -953,6 +975,7 @@ 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,
  };