[PATCH v7 08/15] s390/vfio_ap: add qlink from ap_matrix_mdev struct to vfio_ap_queue struct

Tony Krowiak
2020-04-07T19:21:36Z

Currently, a vfio_ap_queue struct is created for every queue device probed
which is then added to a hash table of all queues probed by the vfio_ap
device driver. This list could get quite large making retrieval
expensive. In order to make retrieval of a vfio_ap_queue struct more
efficient when we already have a pointer to the ap_matrix_mdev to which the
queue's APQN is assigned, let's go ahead and add a link from the
ap_matrix_mdev struct to the vfio_ap_queue struct.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 29 +++++++++++++++++++++++----
drivers/s390/crypto/vfio_ap_private.h | 2 ++
2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 25b7d978e3fd..6ee1ebe3f207 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -38,6 +38,19 @@ struct vfio_ap_queue *vfio_ap_get_queue(unsigned long apqn)
return NULL;
}

+struct vfio_ap_queue *vfio_ap_get_mdev_queue(struct ap_matrix_mdev *matrix_mdev,
+ unsigned long apqn)
+{
+ struct vfio_ap_queue *q;
+
+ hash_for_each_possible(matrix_mdev->qtable, q, mdev_qnode, apqn) {
+ if (q->apqn == apqn)
+ return q;
+ }
+
+ return NULL;
+}
+
/**
* vfio_ap_wait_for_irqclear
* @apqn: The AP Queue number
@@ -325,6 +338,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
matrix_mdev->mdev = mdev;
vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_crycb);
+ hash_init(matrix_mdev->qtable);
mdev_set_drvdata(mdev, matrix_mdev);
matrix_mdev->pqap_hook.hook = handle_pqap;
matrix_mdev->pqap_hook.owner = THIS_MODULE;
@@ -594,7 +608,7 @@ static int vfio_ap_mdev_filter_matrix(struct ap_matrix_mdev *matrix_mdev,
* filter the APQI.
*/
apqn = AP_MKQID(apid, apqi);
- if (!vfio_ap_get_queue(apqn)) {
+ if (!vfio_ap_get_mdev_queue(matrix_mdev, apqn)) {
if (filter_apids)
clear_bit_inv(apid, shadow_crycb->apm);
else
@@ -624,7 +638,6 @@ static bool vfio_ap_mdev_configure_crycb(struct ap_matrix_mdev *matrix_mdev)
vfio_ap_matrix_init(&matrix_dev->info, &shadow_crycb);
napm = bitmap_weight(matrix_mdev->matrix.apm, AP_DEVICES);
naqm = bitmap_weight(matrix_mdev->matrix.aqm, AP_DOMAINS);
-
/*
* If there are no APIDs or no APQIs assigned to the matrix mdev,
* then no APQNs shall be assigned to the guest CRYCB.
@@ -636,6 +649,7 @@ static bool vfio_ap_mdev_configure_crycb(struct ap_matrix_mdev *matrix_mdev)
*/
napm = vfio_ap_mdev_filter_matrix(matrix_mdev, &shadow_crycb,
true);
+
/*
* If there are no APQNs that can be assigned to the guest's
* CRYCB after filtering, then try filtering the APQIs.
@@ -697,8 +711,10 @@ static void vfio_ap_mdev_qlinks_for_apid(struct ap_matrix_mdev *matrix_mdev,
for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
matrix_mdev->matrix.aqm_max + 1) {
q = vfio_ap_get_queue(AP_MKQID(apid, apqi));
- if (q)
+ if (q) {
q->matrix_mdev = matrix_mdev;
+ hash_add(matrix_mdev->qtable, &q->mdev_qnode, q->apqn);
+ }
}
}

@@ -871,8 +887,10 @@ static void vfio_ap_mdev_qlinks_for_apqi(struct ap_matrix_mdev *matrix_mdev,
for_each_set_bit_inv(apid, matrix_mdev->matrix.apm,
matrix_mdev->matrix.apm_max + 1) {
q = vfio_ap_get_queue(AP_MKQID(apid, apqi));
- if (q)
+ if (q) {
q->matrix_mdev = matrix_mdev;
+ hash_add(matrix_mdev->qtable, &q->mdev_qnode, q->apqn);
+ }
}
}

@@ -1536,6 +1554,7 @@ static void vfio_ap_mdev_for_queue(struct vfio_ap_queue *q)
if (test_bit_inv(apid, matrix_mdev->matrix.apm) &&
test_bit_inv(apqi, matrix_mdev->matrix.aqm)) {
q->matrix_mdev = matrix_mdev;
+ hash_add(matrix_mdev->qtable, &q->mdev_qnode, q->apqn);
break;
}
}
@@ -1573,6 +1592,8 @@ void vfio_ap_mdev_remove_queue(struct ap_queue *queue)
vfio_ap_mdev_reset_queue(apid, apqi, 1);
vfio_ap_irq_disable(q);
hash_del(&q->qnode);
+ if (q->matrix_mdev)
+ hash_del(&q->mdev_qnode);
kfree(q);
mutex_unlock(&matrix_dev->lock);
}
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index 87cc270c3212..794c60a767d2 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -89,6 +89,7 @@ struct ap_matrix_mdev {
struct kvm *kvm;
struct kvm_s390_module_hook pqap_hook;
struct mdev_device *mdev;
+ DECLARE_HASHTABLE(qtable, 8);
};

extern int vfio_ap_mdev_register(void);
@@ -101,6 +102,7 @@ struct vfio_ap_queue {
#define VFIO_AP_ISC_INVALID 0xff
unsigned char saved_isc;
struct hlist_node qnode;
+ struct hlist_node mdev_qnode;
};

int vfio_ap_mdev_probe_queue(struct ap_queue *queue);
--
2.21.1