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

From: Tony Krowiak <akrowiak@linux.ibm.com>
To: Halil Pasic <pasic@linux.ibm.com>
Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, freude@linux.ibm.com,
	borntraeger@de.ibm.com, cohuck@redhat.com,
	mjrosato@linux.ibm.com, alex.williamson@redhat.com,
	kwankhede@nvidia.com, fiuczy@linux.ibm.com,
	frankja@linux.ibm.com, david@redhat.com, hca@linux.ibm.com,
	gor@linux.ibm.com
Subject: Re: [PATCH v13 08/15] s390/vfio-ap: sysfs attribute to display the guest's matrix
Date: Thu, 28 Jan 2021 16:29:44 -0500	[thread overview]
Message-ID: <6b526a2c-138c-55ad-d3f0-9c96558b255b@linux.ibm.com> (raw)
In-Reply-To: <20210111235806.5df42658.pasic@linux.ibm.com>

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

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,
>>   };
>>   