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

Halil Pasic
2021-01-11T22:58:06Z

On Tue, 22 Dec 2020 20:15:59 -0500
Tony Krowiak <akrowiak@linux.ibm.com> wrote:

> 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. :(

> ---
> 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,
> };
>