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

[Tony Krowiak <akrowiak@xxxxxxxxxxxxx>]

On 1/11/21 5:58 PM, Halil Pasic wrote:
> On Tue, 22 Dec 2020 20:15:59 -0500
> Tony Krowiak <akrowiak@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
>
> 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.

> > ---
> >   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,
> >   };
> >