From 3b1eab7fb9da69c9af129058ed5aebb93d40d623 Mon Sep 17 00:00:00 2001 From: Tony Krowiak Date: Tue, 25 Sep 2018 19:16:23 -0400 Subject: [PATCH] s390: vfio-ap: sysfs interfaces to configure control domains Provides the sysfs interfaces for: 1. Assigning AP control domains to the mediated matrix device 2. Unassigning AP control domains from a mediated matrix device 3. Displaying the control domains assigned to a mediated matrix device The IDs of the AP control domains assigned to the mediated matrix device are stored in an AP domain mask (ADM). The bits in the ADM, from most significant to least significant bit, correspond to AP domain numbers 0 to 255. On some systems, the maximum allowable domain number may be less than 255 - depending upon the host's AP configuration - and assignment may be rejected if the input domain ID exceeds the limit. When a control domain is assigned, the bit corresponding its domain ID will be set in the ADM. Likewise, when a domain is unassigned, the bit corresponding to its domain ID will be cleared in the ADM. The relevant sysfs structures are: /sys/devices/vfio_ap/matrix/ ...... [mdev_supported_types] ......... [vfio_ap-passthrough] ............ [devices] ...............[$uuid] .................. assign_control_domain .................. unassign_control_domain To assign a control domain to the $uuid mediated matrix device's ADM, write its domain number to the assign_control_domain file. To unassign a domain, write its domain number to the unassign_control_domain file. The domain number is specified using conventional semantics: If it begins with 0x the number will be parsed as a hexadecimal (case insensitive) number; if it begins with 0, it is parsed as an octal number; otherwise, it will be parsed as a decimal number. For example, to assign control domain 173 (0xad) to the mediated matrix device $uuid: echo 173 > assign_control_domain or echo 0255 > assign_control_domain or echo 0xad > assign_control_domain To unassign control domain 173 (0xad): echo 173 > unassign_control_domain or echo 0255 > unassign_control_domain or echo 0xad > unassign_control_domain The assignment will be rejected if the APQI exceeds the maximum value for an AP domain: * If the AP Extended Addressing (APXA) facility is installed, the max value is 255 * Else the max value is 15 Signed-off-by: Tony Krowiak Reviewed-by: Halil Pasic Reviewed-by: Cornelia Huck Tested-by: Michael Mueller Tested-by: Farhan Ali Tested-by: Pierre Morel Message-Id: <20180925231641.4954-9-akrowiak@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger --- drivers/s390/crypto/vfio_ap_ops.c | 112 ++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index e9a2ad4ddfd6..a6c08cd2ed0f 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -516,11 +516,123 @@ static ssize_t unassign_domain_store(struct device *dev, } DEVICE_ATTR_WO(unassign_domain); +/** + * assign_control_domain_store + * + * @dev: the matrix device + * @attr: the mediated matrix device's assign_control_domain attribute + * @buf: a buffer containing the domain ID to be assigned + * @count: the number of bytes in @buf + * + * Parses the domain ID from @buf and sets the corresponding bit in the mediated + * matrix device's ADM. + * + * Returns the number of bytes processed if the domain ID is valid; otherwise, + * returns one of the following errors: + * -EINVAL if the ID is not a number + * -ENODEV if the ID exceeds the maximum value configured for the system + */ +static ssize_t assign_control_domain_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + unsigned long id; + struct mdev_device *mdev = mdev_from_dev(dev); + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + + ret = kstrtoul(buf, 0, &id); + if (ret) + return ret; + + if (id > matrix_mdev->matrix.adm_max) + return -ENODEV; + + /* Set the bit in the ADM (bitmask) corresponding to the AP control + * domain number (id). The bits in the mask, from most significant to + * least significant, correspond to IDs 0 up to the one less than the + * number of control domains that can be assigned. + */ + mutex_lock(&matrix_dev->lock); + set_bit_inv(id, matrix_mdev->matrix.adm); + mutex_unlock(&matrix_dev->lock); + + return count; +} +DEVICE_ATTR_WO(assign_control_domain); + +/** + * unassign_control_domain_store + * + * @dev: the matrix device + * @attr: the mediated matrix device's unassign_control_domain attribute + * @buf: a buffer containing the domain ID to be unassigned + * @count: the number of bytes in @buf + * + * Parses the domain ID from @buf and clears the corresponding bit in the + * mediated matrix device's ADM. + * + * Returns the number of bytes processed if the domain ID is valid; otherwise, + * returns one of the following errors: + * -EINVAL if the ID is not a number + * -ENODEV if the ID exceeds the maximum value configured for the system + */ +static ssize_t unassign_control_domain_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + unsigned long domid; + struct mdev_device *mdev = mdev_from_dev(dev); + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + unsigned long max_domid = matrix_mdev->matrix.adm_max; + + ret = kstrtoul(buf, 0, &domid); + if (ret) + return ret; + if (domid > max_domid) + return -ENODEV; + + mutex_lock(&matrix_dev->lock); + clear_bit_inv(domid, matrix_mdev->matrix.adm); + mutex_unlock(&matrix_dev->lock); + + return count; +} +DEVICE_ATTR_WO(unassign_control_domain); + +static ssize_t control_domains_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + unsigned long id; + int nchars = 0; + int n; + char *bufpos = buf; + struct mdev_device *mdev = mdev_from_dev(dev); + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); + unsigned long max_domid = matrix_mdev->matrix.adm_max; + + mutex_lock(&matrix_dev->lock); + for_each_set_bit_inv(id, matrix_mdev->matrix.adm, max_domid + 1) { + n = sprintf(bufpos, "%04lx\n", id); + bufpos += n; + nchars += n; + } + mutex_unlock(&matrix_dev->lock); + + return nchars; +} +DEVICE_ATTR_RO(control_domains); + static struct attribute *vfio_ap_mdev_attrs[] = { &dev_attr_assign_adapter.attr, &dev_attr_unassign_adapter.attr, &dev_attr_assign_domain.attr, &dev_attr_unassign_domain.attr, + &dev_attr_assign_control_domain.attr, + &dev_attr_unassign_control_domain.attr, + &dev_attr_control_domains.attr, NULL, };