On 2/22/19 10:29 AM, Pierre Morel wrote:
We need to associate the ap_vfio_queue, which will hold the
per queue information for interrupt with a matrix mediated device
which hold the configuration and the way to the CRYCB.
Let's do this when assigning a APID or a APQI to the mediated device
and clear the relation when unassigning.
Queuing the devices on a list of free devices and testing the
matrix_mdev pointer to the associated matrix allow us to know
if the queue is associated to the matrix device and associated
or not to a mediated device.
When resetting an AP queue we must wait until there are no more
messages in the message queue before considering the queue is really
in a clean state.
Let's do it and wait until the status response code indicate the
queue is empty after issuing a PAPQ/ZAPQ instruction.
Being at work on the reset function, let's simplify
vfio_ap_mdev_reset_queue and vfio_ap_mdev_reset_queues by using the
vfio_ap_queue structure as parameter.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 385 +++++++++++++++++++-------------------
1 file changed, 189 insertions(+), 196 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 900b9cf..172d6eb 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -24,6 +24,57 @@
#define VFIO_AP_MDEV_TYPE_HWVIRT "passthrough"
#define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
+/**
+ * vfio_ap_get_queue: Retrieve a queue with a specific APQN from a list
+ * @apqn: The queue APQN
+ *
+ * Retrieve a queue with a specific APQN from the list of the
+ * devices associated with a list.
+ *
+ * Returns the pointer to the associated vfio_ap_queue
+ */
+struct vfio_ap_queue *vfio_ap_get_queue(int apqn, struct list_head *l)
+{
+ struct vfio_ap_queue *q;
+
+ list_for_each_entry(q, l, list)
+ if (q->apqn == apqn)
+ return q;
+ return NULL;
+}
I think you can simplify this patch as well as save a number of LOCs by
going restoring your previous version of this function that used the
driver_find_device() function to retrieve the queue with a specific
APQN. Please see the rest of my comments for further clarification.
+
+static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
+{
+ struct ap_queue_status status;
+ int retry = 20;
+
+ do {
+ status = ap_zapq(q->apqn);
+ switch (status.response_code) {
+ case AP_RESPONSE_NORMAL:
+ while (!status.queue_empty && retry--) {
+ msleep(20);
+ status = ap_tapq(q->apqn, NULL);
+ }
+ if (retry <= 0)
+ pr_warn("%s: queue 0x%04x not empty\n",
+ __func__, q->apqn);
+ return 0;
+ case AP_RESPONSE_RESET_IN_PROGRESS:
+ case AP_RESPONSE_BUSY:
+ msleep(20);
+ break;
+ default:
+ /* things are really broken, give up */
+ pr_warn("%s: zapq error %02x on apqn 0x%04x\n",
+ __func__, status.response_code, q->apqn);
+ return -EIO;
+ }
+ } while (retry--);
+
+ return -EBUSY;
+}
+
static void vfio_ap_matrix_init(struct ap_config_info *info,
struct ap_matrix *matrix)
{
@@ -45,6 +96,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
return -ENOMEM;
}
+ INIT_LIST_HEAD(&matrix_mdev->qlist);
vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
mdev_set_drvdata(mdev, matrix_mdev);
mutex_lock(&matrix_dev->lock);
@@ -113,162 +165,160 @@ static struct attribute_group *vfio_ap_mdev_type_groups[] = {
NULL,
};
-struct vfio_ap_queue_reserved {
- unsigned long *apid;
- unsigned long *apqi;
- bool reserved;
-};
+static void vfio_ap_free_queue(int apqn, struct ap_matrix_mdev *matrix_mdev)
+{
+ struct vfio_ap_queue *q;
+
+ q = vfio_ap_get_queue(apqn, &matrix_mdev->qlist);
If you restore the previous version of vfio_ap_get_queue(), we don't
need the qlist to retrieve the q. The apqn is sufficient.
+ if (!q)
+ return;
+ q->matrix_mdev = NULL;
+ vfio_ap_mdev_reset_queue(q);
+ list_move(&q->list, &matrix_dev->free_list);
If we get rid of the qlist and free_list, then we don't need the
list_move function.
+}
/**
- * vfio_ap_has_queue
- *
- * @dev: an AP queue device
- * @data: a struct vfio_ap_queue_reserved reference
- *
- * Flags whether the AP queue device (@dev) has a queue ID containing the APQN,
- * apid or apqi specified in @data:
+ * vfio_ap_put_all_domains:
*
- * - If @data contains both an apid and apqi value, then @data will be flagged
- * as reserved if the APID and APQI fields for the AP queue device matches
+ * @matrix_mdev: the matrix mediated device for which we want to associate
+ * all available queues with a given apqi.
+ * @apid: The apid which associated with all defined APQI of the
+ * mediated device will define a AP queue.
*
- * - If @data contains only an apid value, @data will be flagged as
- * reserved if the APID field in the AP queue device matches
- *
- * - If @data contains only an apqi value, @data will be flagged as
- * reserved if the APQI field in the AP queue device matches
- *
- * Returns 0 to indicate the input to function succeeded. Returns -EINVAL if
- * @data does not contain either an apid or apqi.
+ * We remove the queue from the list of queues associated with the
+ * mediated device and put them back to the free list of the matrix
+ * device and clear the matrix_mdev pointer.
*/
-static int vfio_ap_has_queue(struct device *dev, void *data)
+static void vfio_ap_put_all_domains(struct ap_matrix_mdev *matrix_mdev,
+ int apid)
{
- struct vfio_ap_queue_reserved *qres = data;
- struct ap_queue *ap_queue = to_ap_queue(dev);
- ap_qid_t qid;
- unsigned long id;
+ int apqi, apqn;
- if (qres->apid && qres->apqi) {
- qid = AP_MKQID(*qres->apid, *qres->apqi);
- if (qid == ap_queue->qid)
- qres->reserved = true;
- } else if (qres->apid && !qres->apqi) {
- id = AP_QID_CARD(ap_queue->qid);
- if (id == *qres->apid)
- qres->reserved = true;
- } else if (!qres->apid && qres->apqi) {
- id = AP_QID_QUEUE(ap_queue->qid);
- if (id == *qres->apqi)
- qres->reserved = true;
- } else {
- return -EINVAL;
+ for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, AP_DOMAINS) {
+ apqn = AP_MKQID(apid, apqi);
+ vfio_ap_free_queue(apqn, matrix_mdev);
}
-
- return 0;
}
/**
- * vfio_ap_verify_queue_reserved
- *
- * @matrix_dev: a mediated matrix device
- * @apid: an AP adapter ID
- * @apqi: an AP queue index
- *
- * Verifies that the AP queue with @apid/@apqi is reserved by the VFIO AP device
- * driver according to the following rules:
+ * vfio_ap_put_all_cards:
*
- * - If both @apid and @apqi are not NULL, then there must be an AP queue
- * device bound to the vfio_ap driver with the APQN identified by @apid and
- * @apqi
+ * @matrix_mdev: the matrix mediated device for which we want to associate
+ * all available queues with a given apqi.
+ * @apqi: The apqi which associated with all defined APID of the
+ * mediated device will define a AP queue.
*
- * - If only @apid is not NULL, then there must be an AP queue device bound
- * to the vfio_ap driver with an APQN containing @apid
- *
- * - If only @apqi is not NULL, then there must be an AP queue device bound
- * to the vfio_ap driver with an APQN containing @apqi
- *
- * Returns 0 if the AP queue is reserved; otherwise, returns -EADDRNOTAVAIL.
+ * We remove the queue from the list of queues associated with the
+ * mediated device and put them back to the free list of the matrix
+ * device and clear the matrix_mdev pointer.
*/
-static int vfio_ap_verify_queue_reserved(unsigned long *apid,
- unsigned long *apqi)
+static void vfio_ap_put_all_cards(struct ap_matrix_mdev *matrix_mdev, int apqi)
{
- int ret;
- struct vfio_ap_queue_reserved qres;
+ int apid, apqn;
- qres.apid = apid;
- qres.apqi = apqi;
- qres.reserved = false;
-
- ret = driver_for_each_device(&matrix_dev->vfio_ap_drv->driver, NULL,
- &qres, vfio_ap_has_queue);
- if (ret)
- return ret;
-
- if (qres.reserved)
- return 0;
-
- return -EADDRNOTAVAIL;
+ for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, AP_DEVICES) {
+ apqn = AP_MKQID(apid, apqi);
+ vfio_ap_free_queue(apqn, matrix_mdev);
+ }
}
-static int
-vfio_ap_mdev_verify_queues_reserved_for_apid(struct ap_matrix_mdev *matrix_mdev,
- unsigned long apid)
+static void move_and_set(struct list_head *src, struct list_head *dst,
+ struct ap_matrix_mdev *matrix_mdev)
{
- int ret;
- unsigned long apqi;
- unsigned long nbits = matrix_mdev->matrix.aqm_max + 1;
-
- if (find_first_bit_inv(matrix_mdev->matrix.aqm, nbits) >= nbits)
- return vfio_ap_verify_queue_reserved(&apid, NULL);
+ struct vfio_ap_queue *q, *qtmp;
- for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, nbits) {
- ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
- if (ret)
- return ret;
+ list_for_each_entry_safe(q, qtmp, src, list) {
+ list_move(&q->list, dst);
+ q->matrix_mdev = matrix_mdev;
}
If we get rid of the lists, this function becomes unnecessary.
-
+}
+/**
+ * vfio_ap_get_all_domains:
+ *
+ * @matrix_mdev: the matrix mediated device for which we want to associate
+ * all available queues with a given apqi.
+ * @apqi: The apqi which associated with all defined APID of the
+ * mediated device will define a AP queue.
+ *
+ * We define a local list to put all queues we find on the matrix device
+ * free list when associating the apqi with all already defined apid for
+ * this matrix mediated device.
+ *
+ * If we can get all the devices we roll them to the mediated device list
+ * If we get errors we unroll them to the free list.
+ */
+static int vfio_ap_get_all_domains(struct ap_matrix_mdev *matrix_mdev, int apid)
+{
+ int apqi, apqn;
+ int ret = 0;
+ struct vfio_ap_queue *q;
+ struct list_head q_list;
+
+ INIT_LIST_HEAD(&q_list);
+
+ for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, AP_DOMAINS) {
+ apqn = AP_MKQID(apid, apqi);
+ q = vfio_ap_get_queue(apqn, &matrix_dev->free_list);
+ if (!q) {
+ ret = -EADDRNOTAVAIL;
+ goto rewind;
If we get rid of the lists, there is no need to rewind
+ }
+ if (q->matrix_mdev) {
+ ret = -EADDRINUSE;
+ goto rewind;
If we get rid of the lists, there is no need to rewind
+ }
+ list_move(&q->list, &q_list);
If we get rid of the lists, there is no need to move the queue to
q_list.
+ }
+ move_and_set(&q_list, &matrix_mdev->qlist, matrix_mdev);
If we get rid of the lists, this call becomes unnecessary.
return 0;
+rewind:
+ move_and_set(&q_list, &matrix_dev->free_list, NULL);
If we get rid of the lists, this call becomes unnecessary.
+ return ret;
}
-
/**
- * vfio_ap_mdev_verify_no_sharing
+ * vfio_ap_get_all_cards:
*
- * Verifies that the APQNs derived from the cross product of the AP adapter IDs
- * and AP queue indexes comprising the AP matrix are not configured for another
- * mediated device. AP queue sharing is not allowed.
+ * @matrix_mdev: the matrix mediated device for which we want to associate
+ * all available queues with a given apqi.
+ * @apqi: The apqi which associated with all defined APID of the
+ * mediated device will define a AP queue.
*
- * @matrix_mdev: the mediated matrix device
+ * We define a local list to put all queues we find on the matrix device
+ * free list when associating the apqi with all already defined apid for
+ * this matrix mediated device.
*
- * Returns 0 if the APQNs are not shared, otherwise; returns -EADDRINUSE.
+ * If we can get all the devices we roll them to the mediated device list
+ * If we get errors we unroll them to the free list.
*/
-static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev)
+static int vfio_ap_get_all_cards(struct ap_matrix_mdev *matrix_mdev, int apqi)
{
- struct ap_matrix_mdev *lstdev;
- DECLARE_BITMAP(apm, AP_DEVICES);
- DECLARE_BITMAP(aqm, AP_DOMAINS);
-
- list_for_each_entry(lstdev, &matrix_dev->mdev_list, node) {
- if (matrix_mdev == lstdev)
- continue;
-
- memset(apm, 0, sizeof(apm));
- memset(aqm, 0, sizeof(aqm));
-
- /*
- * We work on full longs, as we can only exclude the leftover
- * bits in non-inverse order. The leftover is all zeros.
- */
- if (!bitmap_and(apm, matrix_mdev->matrix.apm,
- lstdev->matrix.apm, AP_DEVICES))
- continue;
-
- if (!bitmap_and(aqm, matrix_mdev->matrix.aqm,
- lstdev->matrix.aqm, AP_DOMAINS))
- continue;
-
- return -EADDRINUSE;
+ int apid, apqn;
+ int ret = 0;
+ struct vfio_ap_queue *q;
+ struct list_head q_list;
+ struct ap_matrix_mdev *tmp = NULL;
+
+ INIT_LIST_HEAD(&q_list);
+
+ for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, AP_DEVICES) {
+ apqn = AP_MKQID(apid, apqi);
+ q = vfio_ap_get_queue(apqn, &matrix_dev->free_list);
+ if (!q) {
+ ret = -EADDRNOTAVAIL;
+ goto rewind;
No lists, no rewind necessary
+ }
+ if (q->matrix_mdev) {
+ ret = -EADDRINUSE;
+ goto rewind;
No lists, no rewind necessary
+ }
+ list_move(&q->list, &q_list);
No lists, no need to move the queue to q_list
}
-
+ tmp = matrix_mdev;
+ move_and_set(&q_list, &matrix_mdev->qlist, matrix_mdev);
No lists, no need to move and set.
return 0;
+rewind:
+ move_and_set(&q_list, &matrix_dev->free_list, NULL);
No lists, no need to move and set.
+ return ret;
}
/**
@@ -330,21 +380,15 @@ static ssize_t assign_adapter_store(struct device *dev,
*/
mutex_lock(&matrix_dev->lock);
- ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);
+ ret = vfio_ap_get_all_domains(matrix_mdev, apid);
if (ret)
goto done;
set_bit_inv(apid, matrix_mdev->matrix.apm);
- ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
- if (ret)
- goto share_err;
-
ret = count;
goto done;
-share_err:
- clear_bit_inv(apid, matrix_mdev->matrix.apm);
done:
mutex_unlock(&matrix_dev->lock);
@@ -391,32 +435,13 @@ static ssize_t unassign_adapter_store(struct device *dev,
mutex_lock(&matrix_dev->lock);
clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+ vfio_ap_put_all_domains(matrix_mdev, apid);
mutex_unlock(&matrix_dev->lock);
return count;
}
static DEVICE_ATTR_WO(unassign_adapter);
-static int
-vfio_ap_mdev_verify_queues_reserved_for_apqi(struct ap_matrix_mdev *matrix_mdev,
- unsigned long apqi)
-{
- int ret;
- unsigned long apid;
- unsigned long nbits = matrix_mdev->matrix.apm_max + 1;
-
- if (find_first_bit_inv(matrix_mdev->matrix.apm, nbits) >= nbits)
- return vfio_ap_verify_queue_reserved(NULL, &apqi);
-
- for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, nbits) {
- ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
- if (ret)
- return ret;
- }
-
- return 0;
-}
-
/**
* assign_domain_store
*
@@ -471,21 +496,15 @@ static ssize_t assign_domain_store(struct device *dev,
mutex_lock(&matrix_dev->lock);
- ret = vfio_ap_mdev_verify_queues_reserved_for_apqi(matrix_mdev, apqi);
+ ret = vfio_ap_get_all_cards(matrix_mdev, apqi);
if (ret)
goto done;
set_bit_inv(apqi, matrix_mdev->matrix.aqm);
- ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
- if (ret)
- goto share_err;
-
ret = count;
goto done;
-share_err:
- clear_bit_inv(apqi, matrix_mdev->matrix.aqm);
done:
mutex_unlock(&matrix_dev->lock);
@@ -533,6 +552,7 @@ static ssize_t unassign_domain_store(struct device *dev,
mutex_lock(&matrix_dev->lock);
clear_bit_inv((unsigned long)apqi, matrix_mdev->matrix.aqm);
+ vfio_ap_put_all_cards(matrix_mdev, apqi);
mutex_unlock(&matrix_dev->lock);
return count;
@@ -790,49 +810,22 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
return NOTIFY_OK;
}
-static int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
- unsigned int retry)
-{
- struct ap_queue_status status;
-
- do {
- status = ap_zapq(AP_MKQID(apid, apqi));
- switch (status.response_code) {
- case AP_RESPONSE_NORMAL:
- return 0;
- case AP_RESPONSE_RESET_IN_PROGRESS:
- case AP_RESPONSE_BUSY:
- msleep(20);
- break;
- default:
- /* things are really broken, give up */
- return -EIO;
- }
- } while (retry--);
-
- return -EBUSY;
-}
-
static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
{
int ret;
int rc = 0;
- unsigned long apid, apqi;
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+ struct vfio_ap_queue *q;
- for_each_set_bit_inv(apid, matrix_mdev->matrix.apm,
- matrix_mdev->matrix.apm_max + 1) {
- for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
- matrix_mdev->matrix.aqm_max + 1) {
- ret = vfio_ap_mdev_reset_queue(apid, apqi, 1);
- /*
- * Regardless whether a queue turns out to be busy, or
- * is not operational, we need to continue resetting
- * the remaining queues.
- */
- if (ret)
- rc = ret;
- }
+ list_for_each_entry(q, &matrix_mdev->qlist, list) {
+ ret = vfio_ap_mdev_reset_queue(q);
+ /*
+ * Regardless whether a queue turns out to be busy, or
+ * is not operational, we need to continue resetting
+ * the remaining queues but notice the last error code.
+ */
+ if (ret)
+ rc = ret;
}
There is no need for this change. Without the lists, we can keep the
code as-is above. Having the list buys us absolutely nothing here.
return rc;
