On 9/17/20 10:34 AM, Cornelia Huck wrote:
On Fri, 21 Aug 2020 15:56:07 -0400 Tony Krowiak <[email protected]> wrote:The matrix of adapters and domains configured in a guest's CRYCB 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 <[email protected]> --- drivers/s390/crypto/vfio_ap_ops.c | 58 +++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index efb229033f9e..30bf23734af6 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -1119,6 +1119,63 @@ static ssize_t matrix_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(matrix);+static ssize_t guest_matrix_show(struct device *dev,+ struct device_attribute *attr, 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->shadow_apcb.apm_max + 1; + unsigned long naqm_bits = matrix_mdev->shadow_apcb.aqm_max + 1; + int nchars = 0; + int n; + + if (!vfio_ap_mdev_has_crycb(matrix_mdev)) + return -ENODEV; + + apid1 = find_first_bit_inv(matrix_mdev->shadow_apcb.apm, napm_bits); + apqi1 = find_first_bit_inv(matrix_mdev->shadow_apcb.aqm, naqm_bits); + + mutex_lock(&matrix_dev->lock); + + if ((apid1 < napm_bits) && (apqi1 < naqm_bits)) { + for_each_set_bit_inv(apid, matrix_mdev->shadow_apcb.apm, + napm_bits) { + for_each_set_bit_inv(apqi, + matrix_mdev->shadow_apcb.aqm, + naqm_bits) { + n = sprintf(bufpos, "%02lx.%04lx\n", apid, + apqi); + bufpos += n; + nchars += n; + } + } + } else if (apid1 < napm_bits) { + for_each_set_bit_inv(apid, matrix_mdev->shadow_apcb.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->shadow_apcb.aqm, + naqm_bits) { + n = sprintf(bufpos, ".%04lx\n", apqi); + bufpos += n; + nchars += n; + } + } + + mutex_unlock(&matrix_dev->lock); + + return nchars; +}This basically looks like a version of matrix_show() operating on the shadow apcb. I'm wondering if we could consolidate these two functions by passing in the structure to operate on as a parameter? Might not be worth the effort, though.
We still need the two functions because they back the mdev's sysfs matrix and guest_matrix attributes, but we could call a function. I'm not sure it buys us much though.

