Messages in this thread | | | Subject | Re: [PATCH v6 10/21] s390: vfio-ap: sysfs interfaces to configure adapters | From | Pierre Morel <> | Date | Mon, 9 Jul 2018 14:11:19 +0200 |
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On 29/06/2018 23:11, Tony Krowiak wrote: > Provides the sysfs interfaces for assigning AP adapters to > and unassigning AP adapters from a mediated matrix device. > > The IDs of the AP adapters assigned to the mediated matrix > device are stored in an AP mask (APM). The bits in the APM, > from most significant to least significant bit, correspond to > AP adapter ID (APID) 0 to 255. When an adapter is assigned, the > bit corresponding the APID will be set in the APM. > Likewise, when an adapter is unassigned, the bit corresponding > to the APID will be cleared from the APM. > > The relevant sysfs structures are: > > /sys/devices/vfio_ap > ... [matrix] > ...... [mdev_supported_types] > ......... [vfio_ap-passthrough] > ............ [devices] > ...............[$uuid] > .................. assign_adapter > .................. unassign_adapter > > To assign an adapter to the $uuid mediated matrix device's APM, > write the APID to the assign_adapter file. To unassign an adapter, > write the APID to the unassign_adapter file. The APID is specified > using conventional semantics: If it begins with 0x the number will > be parsed as a hexadecimal number; if it begins with a 0 the number > will be parsed as an octal number; otherwise, it will be parsed as a > decimal number. > > For example, to assign adapter 173 (0xad) to the mediated matrix > device $uuid: > > echo 173 > assign_adapter > > or > > echo 0xad > assign_adapter > > or > > echo 0255 > assign_adapter > > To unassign adapter 173 (0xad): > > echo 173 > unassign_adapter > > or > > echo 0xad > unassign_adapter > > or > > echo 0255 > unassign_adapter > > The assignment will be rejected: > > * If the APID exceeds the maximum value for an AP adapter: > * If the AP Extended Addressing (APXA) facility is > installed, the max value is 255 > * Else the max value is 64 > > * If no AP domains have yet been assigned and there are > no AP queues bound to the VFIO AP driver that have an APQN > with an APID matching that of the AP adapter being assigned. > > * If any of the APQNs that can be derived from the cross product > of the APID being assigned and the AP queue index (APQI) of > each of the AP domains previously assigned can not be matched > with an APQN of an AP queue device reserved by the VFIO AP > driver. > > Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> > --- > drivers/s390/crypto/vfio_ap_ops.c | 317 +++++++++++++++++++++++++++++++++++++ > 1 files changed, 317 insertions(+), 0 deletions(-) > > diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c > index bf7ed9f..a4351bd 100644 > --- a/drivers/s390/crypto/vfio_ap_ops.c > +++ b/drivers/s390/crypto/vfio_ap_ops.c > @@ -16,6 +16,7 @@ > > #define VFOP_AP_MDEV_TYPE_HWVIRT "passthrough" > #define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device" > +#define KVM_AP_MASK_BYTES(n) DIV_ROUND_UP(n, BITS_PER_BYTE) > > DEFINE_SPINLOCK(mdev_list_lock); > LIST_HEAD(mdev_list); > @@ -116,9 +117,325 @@ static ssize_t device_api_show(struct kobject *kobj, struct device *dev, > NULL, > }; > > +struct vfio_ap_qid_reserved { > + ap_qid_t qid; > + bool reserved; > +}; > + > +struct vfio_id_reserved { > + unsigned long id; > + bool reserved; > +}; > + > +/** > + * vfio_ap_qid_reserved > + * > + * @dev: an AP queue device > + * @data: a queue ID > + * > + * Flags whether any AP queue device has a particular qid > + * > + * Returns 0 to indicate the function succeeded > + */ > +static int vfio_ap_queue_has_qid(struct device *dev, void *data) > +{ > + struct vfio_ap_qid_reserved *qid_res = data; > + struct ap_queue *ap_queue = to_ap_queue(dev); > + > + if (qid_res->qid == ap_queue->qid) > + qid_res->reserved = true; > + > + return 0; > +} > + > +/** > + * vfio_ap_queue_has_apid > + * > + * @dev: an AP queue device > + * @data: an AP adapter ID > + * > + * Flags whether any AP queue device has a particular AP adapter ID > + * > + * Returns 0 to indicate the function succeeded > + */ > +static int vfio_ap_queue_has_apid(struct device *dev, void *data) > +{ > + struct vfio_id_reserved *id_res = data; > + struct ap_queue *ap_queue = to_ap_queue(dev); > + > + if (id_res->id == AP_QID_CARD(ap_queue->qid)) > + id_res->reserved = true; > + > + return 0; > +} > + > +/** > + * vfio_ap_verify_qid_reserved > + * > + * @matrix_dev: a mediated matrix device > + * @qid: a qid (i.e., APQN) > + * > + * Verifies that the AP queue with @qid is reserved by the VFIO AP device > + * driver. > + * > + * Returns 0 if the AP queue with @qid is reserved; otherwise, returns -ENODEV. > + */ > +static int vfio_ap_verify_qid_reserved(struct ap_matrix_dev *matrix_dev, > + ap_qid_t qid) > +{ > + int ret; > + struct vfio_ap_qid_reserved qid_res; > + > + qid_res.qid = qid; > + qid_res.reserved = false; > + > + ret = driver_for_each_device(matrix_dev->device.driver, NULL, &qid_res, > + vfio_ap_queue_has_qid); > + if (ret) > + return ret; > + > + if (qid_res.reserved) > + return 0; > + > + return -EPERM; > +} > + > +/** > + * vfio_ap_verify_apid_reserved > + * > + * @matrix_dev: a mediated matrix device > + * @apid: an AP adapter ID > + * > + * Verifies that an AP queue with @apid is reserved by the VFIO AP device > + * driver. > + * > + * Returns 0 if an AP queue with @apid is reserved; otherwise, returns -ENODEV. > + */ > +static int vfio_ap_verify_apid_reserved(struct ap_matrix_dev *matrix_dev, > + const char *mdev_name, > + unsigned long apid) > +{ > + int ret; > + struct vfio_id_reserved id_res; > + > + id_res.id = apid; > + id_res.reserved = false; > + > + ret = driver_for_each_device(matrix_dev->device.driver, NULL, &id_res, > + vfio_ap_queue_has_apid); > + if (ret) > + return ret; > + > + if (id_res.reserved) > + return 0; > + > + pr_err("%s: mdev %s using adapter %02lx not reserved by %s driver", > + VFIO_AP_MODULE_NAME, mdev_name, apid, > + VFIO_AP_DRV_NAME); > + > + return -EPERM; > +} > + > +static int vfio_ap_verify_queues_reserved(struct ap_matrix_dev *matrix_dev, > + const char *mdev_name, > + struct ap_matrix *matrix) > +{ > + unsigned long apid, apqi; > + int ret; > + int rc = 0; > + > + for_each_set_bit_inv(apid, matrix->apm, matrix->apm_max + 1) { > + for_each_set_bit_inv(apqi, matrix->aqm, matrix->aqm_max + 1) { > + ret = vfio_ap_verify_qid_reserved(matrix_dev, > + AP_MKQID(apid, apqi)); > + if (ret == 0) > + continue; > + > + /* > + * We want to log every APQN that is not reserved by > + * the driver, so record the return code, log a message > + * and allow the loop to continue > + */ > + rc = ret; > + pr_err("%s: mdev %s using queue %02lx.%04lx not reserved by %s driver", > + VFIO_AP_MODULE_NAME, mdev_name, apid, > + apqi, VFIO_AP_DRV_NAME); > + } > + } > + > + return rc; > +} > + > +/** > + * vfio_ap_validate_apid > + * > + * @mdev: the mediated device > + * @matrix_mdev: the mediated matrix device > + * @apid: the APID to validate > + * > + * Validates the value of @apid: > + * * If there are no AP domains assigned, then there must be at least > + * one AP queue device reserved by the VFIO AP device driver with an > + * APQN containing @apid. > + * > + * * Else each APQN that can be derived from the intersection of @apid and > + * the IDs of the AP domains already assigned must identify an AP queue > + * that has been reserved by the VFIO AP device driver. > + * > + * Returns 0 if the value of @apid is valid; otherwise, returns an error. > + */ > +static int vfio_ap_validate_apid(struct mdev_device *mdev, > + struct ap_matrix_mdev *matrix_mdev, > + unsigned long apid) > +{ > + int ret; > + unsigned long aqmsz = matrix_mdev->matrix.aqm_max + 1; > + struct device *dev = mdev_parent_dev(mdev); > + struct ap_matrix_dev *matrix_dev = to_ap_matrix_dev(dev); > + struct ap_matrix matrix = matrix_mdev->matrix; > + > + /* If there are any queues assigned to the mediated device */ > + if (find_first_bit_inv(matrix.aqm, aqmsz) < aqmsz) { > + matrix.apm_max = matrix_mdev->matrix.apm_max; > + memset(matrix.apm, 0, > + ARRAY_SIZE(matrix.apm) * sizeof(matrix.apm[0])); > + set_bit_inv(apid, matrix.apm); > + matrix.aqm_max = matrix_mdev->matrix.aqm_max; > + memcpy(matrix.aqm, matrix_mdev->matrix.aqm, > + ARRAY_SIZE(matrix.aqm) * sizeof(matrix.aqm[0])); > + ret = vfio_ap_verify_queues_reserved(matrix_dev, > + matrix_mdev->name, > + &matrix); > + } else { > + ret = vfio_ap_verify_apid_reserved(matrix_dev, > + matrix_mdev->name, apid); > + } > + > + if (ret) > + return ret; > + > + return 0; > +} > + > +/** > + * assign_adapter_store > + * > + * @dev: the matrix device > + * @attr: a mediated matrix device attribute > + * @buf: a buffer containing the adapter ID (APID) to be assigned > + * @count: the number of bytes in @buf > + * > + * Parses the APID from @buf and assigns it to the mediated matrix device. The > + * APID must be a valid value: > + * * The APID value must not exceed the maximum allowable AP adapter ID > + * > + * * If there are no AP domains assigned, then there must be at least > + * one AP queue device reserved by the VFIO AP device driver with an > + * APQN containing @apid.
I do not understand the reason here. Can you develop?
I suppose that by reserved you mean bound. (then use bound) But I still can not understand the reason why.
Beside if I understand correctly what you do it forbid the automatic assignment of a new card plugged into the host.
> + * > + * * Else each APQN that can be derived from the intersection of @apid and > + * the IDs of the AP domains already assigned must identify an AP queue > + * that has been reserved by the VFIO AP device driver. > + * > + * Returns the number of bytes processed if the APID is valid; otherwise returns > + * an error. > + */ > +static ssize_t assign_adapter_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + int ret; > + unsigned long apid; > + struct mdev_device *mdev = mdev_from_dev(dev); > + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); > + unsigned long max_apid = matrix_mdev->matrix.apm_max; > + > + ret = kstrtoul(buf, 0, &apid); > + if (ret || (apid > max_apid)) { > + pr_err("%s: %s: adapter id '%s' not a value from 0 to %02lu(%#04lx)", > + VFIO_AP_MODULE_NAME, __func__, buf, max_apid, max_apid); > + > + return ret ? ret : -EINVAL; > + } > + > + ret = vfio_ap_validate_apid(mdev, matrix_mdev, apid); > + if (ret) > + return ret; > + > + /* Set the bit in the AP mask (APM) corresponding to the AP adapter > + * number (APID). The bits in the mask, from most significant to least > + * significant bit, correspond to APIDs 0-255. > + */ > + set_bit_inv(apid, matrix_mdev->matrix.apm); > + > + return count; > +} > +static DEVICE_ATTR_WO(assign_adapter); > + > +/** > + * unassign_adapter_store > + * > + * @dev: the matrix device > + * @attr: a mediated matrix device attribute > + * @buf: a buffer containing the adapter ID (APID) to be assigned > + * @count: the number of bytes in @buf > + * > + * Parses the APID from @buf and unassigns it from the mediated matrix device. > + * The APID must be a valid value > + * > + * Returns the number of bytes processed if the APID is valid; otherwise returns > + * an error. > + */ > +static ssize_t unassign_adapter_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + int ret; > + unsigned long apid; > + struct mdev_device *mdev = mdev_from_dev(dev); > + struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); > + unsigned long max_apid = matrix_mdev->matrix.apm_max; > + > + ret = kstrtoul(buf, 0, &apid); > + if (ret || (apid > max_apid)) { > + pr_err("%s: %s: adapter id '%s' must be a value from 0 to %02lu(%#04lx)", > + VFIO_AP_MODULE_NAME, __func__, buf, max_apid, max_apid); > + > + return ret ? ret : -EINVAL; > + } > + > + if (!test_bit_inv(apid, matrix_mdev->matrix.apm)) { > + pr_err("%s: %s: adapter id %02lu(%#04lx) not assigned", > + VFIO_AP_MODULE_NAME, __func__, apid, apid); > + > + return -ENODEV; > + } > + > + clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm); > + > + return count; > +} > +DEVICE_ATTR_WO(unassign_adapter); > + > +static struct attribute *vfio_ap_mdev_attrs[] = { > + &dev_attr_assign_adapter.attr, > + &dev_attr_unassign_adapter.attr, > + NULL > +}; > + > +static struct attribute_group vfio_ap_mdev_attr_group = { > + .attrs = vfio_ap_mdev_attrs > +}; > + > +static const struct attribute_group *vfio_ap_mdev_attr_groups[] = { > + &vfio_ap_mdev_attr_group, > + NULL > +}; > + > static const struct mdev_parent_ops vfio_ap_matrix_ops = { > .owner = THIS_MODULE, > .supported_type_groups = vfio_ap_mdev_type_groups, > + .mdev_attr_groups = vfio_ap_mdev_attr_groups, > .create = vfio_ap_mdev_create, > .remove = vfio_ap_mdev_remove, > };
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
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