On 3/24/22 10:09, Jason J. Herne wrote:
On 2/14/22 19:50, Tony Krowiak wrote:
...
@@ -790,13 +788,17 @@ static void vfio_ap_unlink_apqn_fr_mdev(struct
ap_matrix_mdev *matrix_mdev,
q = vfio_ap_mdev_get_queue(matrix_mdev, AP_MKQID(apid, apqi));
/* If the queue is assigned to the matrix mdev, unlink it. */
- if (q)
+ if (q) {
vfio_ap_unlink_queue_fr_mdev(q);
- /* If the queue is assigned to the APCB, store it in @qtable. */
- if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm) &&
- test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm))
- hash_add(qtable->queues, &q->mdev_qnode, q->apqn);
+ /* If the queue is assigned to the APCB, store it in
@qtable. */
+ if (qtable) {
+ if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm) &&
+ test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm))
+ hash_add(qtable->queues, &q->mdev_qnode,
+ q->apqn);
+ }
+ }
}
This appears to be an unrelated change. Does this belong in this patch?
No, that does not belong in this patch, it belongs in patch
[PATCH v18 12/18] s390/vfio-ap: reset queues after adapter/domain
unassignment.
/**
@@ -1271,7 +1273,7 @@ static const struct attribute_group
*vfio_ap_mdev_attr_groups[] = {
* @matrix_mdev: a mediated matrix device
* @kvm: reference to KVM instance
*
- * Note: The matrix_dev->lock must be taken prior to calling
+ * Note: The matrix_dev->mdevs_lock must be taken prior to calling
This also seems to be unrelated.
The change of the name of the matrix_dev->lock to matrix_dev->mdevs_lock
was done in [PATCH v18 09/18] s390/vfio-ap: introduce new mutex to control
access to the KVM pointer; however, this comment is not valid. A commit has
been pushed for upstream merge which includes removal of this comment.
* this function; however, the lock will be temporarily released
while the
* guest's AP configuration is set to avoid a potential lockdep splat.
* The kvm->lock is taken to set the guest's AP configuration
which, under
@@ -1355,7 +1357,7 @@ static int vfio_ap_mdev_iommu_notifier(struct
notifier_block *nb,
* @matrix_mdev: a matrix mediated device
* @kvm: the pointer to the kvm structure being unset.
*
- * Note: The matrix_dev->lock must be taken prior to calling
+ * Note: The matrix_dev->mdevs_lock must be taken prior to calling
Same here.
Ditto
* this function; however, the lock will be temporarily released
while the
* guest's AP configuration is cleared to avoid a potential lockdep
splat.
* The kvm->lock is taken to clear the guest's AP configuration
which, under
@@ -1708,6 +1710,27 @@ static void vfio_ap_mdev_put_qlocks(struct
ap_matrix_mdev *matrix_mdev)
mutex_unlock(&matrix_dev->guests_lock);
}
+static bool vfio_ap_mdev_do_filter_matrix(struct ap_matrix_mdev
*matrix_mdev,
+ struct vfio_ap_queue *q)
+{
+ unsigned long apid = AP_QID_CARD(q->apqn);
+ unsigned long apqi = AP_QID_QUEUE(q->apqn);
+
+ /*
+ * If the queue is being probed because its APID or APQI is in the
+ * process of being added to the host's AP configuration, then
we don't
+ * want to filter the matrix now as the filtering will be done
after
+ * the driver is notified that the AP bus scan operation has
completed
+ * (see the vfio_ap_on_scan_complete callback function).
+ */
+ if (test_bit_inv(apid, matrix_mdev->apm_add) ||
+ test_bit_inv(apqi, matrix_mdev->aqm_add))
+ return false;
+
+
+ return true;
+}
+
int vfio_ap_mdev_probe_queue(struct ap_device *apdev)
{
struct vfio_ap_queue *q;
@@ -1725,10 +1748,15 @@ int vfio_ap_mdev_probe_queue(struct ap_device
*apdev)
vfio_ap_mdev_link_queue(matrix_mdev, q);
memset(apm, 0, sizeof(apm));
set_bit_inv(AP_QID_CARD(q->apqn), apm);
- if (vfio_ap_mdev_filter_matrix(apm, q->matrix_mdev->matrix.aqm,
- q->matrix_mdev))
- vfio_ap_mdev_hotplug_apcb(q->matrix_mdev);
+
+ if (vfio_ap_mdev_do_filter_matrix(q->matrix_mdev, q)) {
+ if (vfio_ap_mdev_filter_matrix(apm,
+ q->matrix_mdev->matrix.aqm,
+ q->matrix_mdev))
+ vfio_ap_mdev_hotplug_apcb(q->matrix_mdev);
+ }
}
+
dev_set_drvdata(&apdev->device, q);
vfio_ap_mdev_put_qlocks(matrix_mdev);
@@ -1783,10 +1811,15 @@ void vfio_ap_mdev_remove_queue(struct
ap_device *apdev)
apid = AP_QID_CARD(q->apqn);
apqi = AP_QID_QUEUE(q->apqn);
- if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm) &&
- test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm)) {
- clear_bit_inv(apid, matrix_mdev->shadow_apcb.apm);
- vfio_ap_mdev_hotplug_apcb(matrix_mdev);
+
+ /*
+ * If the queue is assigned to the guest's APCB, then remove
+ * the adapter's APID from the APCB and hot it into the guest.
+ */
+ if (test_bit_inv(apid, q->matrix_mdev->shadow_apcb.apm) &&
+ test_bit_inv(apqi, q->matrix_mdev->shadow_apcb.aqm)) {
+ clear_bit_inv(apid, q->matrix_mdev->shadow_apcb.apm);
+ vfio_ap_mdev_hotplug_apcb(q->matrix_mdev);
It looks like this a bug fix unrelated to this patch...?
It's not a bug fix, but it is unnecessary. Both what was removed and the
code
added are fine, but the former makes more sense. I have no idea how this
happened other than the code was accidentally changed while merging code
during one of the multitude of rebases undertaken while developing this
series.
@@ -1842,3 +1875,267 @@ int vfio_ap_mdev_resource_in_use(unsigned
long *apm, unsigned long *aqm)
return ret;
}
+
+/**
+ * vfio_ap_mdev_hot_unplug_cfg - hot unplug the adapters, domains
and control
+ * domains that have been removed from the host's
+ * AP configuration from a guest.
+ *
+ * @guest: the guest
+ * @aprem: the adapters that have been removed from the host's AP
configuration
+ * @aqrem: the domains that have been removed from the host's AP
configuration
+ * @cdrem: the control domains that have been removed from the
host's AP
+ * configuration.
+ */
+static void vfio_ap_mdev_hot_unplug_cfg(struct ap_matrix_mdev
*matrix_mdev,
+ unsigned long *aprem,
+ unsigned long *aqrem,
+ unsigned long *cdrem)
+{
+ bool do_hotplug = false;
__bitmap_andnot() returns an int, so I think you should use an int here.
Okay
+ if (!bitmap_empty(aprem, AP_DEVICES)) {
+ do_hotplug |= bitmap_andnot(matrix_mdev->shadow_apcb.apm,
+ matrix_mdev->shadow_apcb.apm,
+ aprem, AP_DEVICES);
Also, replace the |= with an = here. This is the first assignment so no
need to do a logical OR as there is no pre-existing data to preserve.
We don't know which, if any, of the bitmaps (aprem, aqrem, cdrem) passed to
this function contain set bits, so the |= is necessary because this code
block won't be be executed if aprem is empty. That is why the do_hotplug
variable is initialized to false when it is declared (i.e., each of the
bitmaps
might be empty).
+ }
+
+ if (!bitmap_empty(aqrem, AP_DOMAINS)) {
+ do_hotplug |= bitmap_andnot(matrix_mdev->shadow_apcb.aqm,
+ matrix_mdev->shadow_apcb.aqm,
+ aqrem, AP_DEVICES);
+ }
+
+ if (!bitmap_empty(cdrem, AP_DOMAINS))
+ do_hotplug |= bitmap_andnot(matrix_mdev->shadow_apcb.adm,
+ matrix_mdev->shadow_apcb.adm,
+ cdrem, AP_DOMAINS);
+
+ if (do_hotplug)
+ vfio_ap_mdev_hotplug_apcb(matrix_mdev);
+}
+
+/**
+ * vfio_ap_mdev_cfg_remove - determines which guests are using the
adapters,
+ * domains and control domains that have been removed
+ * from the host AP configuration and unplugs them
+ * from those guests.
+ *
+ * @ap_remove: bitmap specifying which adapters have been removed
from the host
+ * config.
+ * @aq_remove: bitmap specifying which domains have been removed
from the host
+ * config.
+ * @cd_remove: bitmap specifying which control domains have been
removed from
+ * the host config.
+ */
...
+/**
+ * vfio_ap_mdev_on_cfg_remove - responds to the removal of adapters,
domains and
+ * control domains from the host AP configuration
+ * by unplugging them from the guests that are
+ * using them.
+ */
+static void vfio_ap_mdev_on_cfg_remove(void)
+{
+ int ap_remove, aq_remove, cd_remove;
These can all be replaced with a single variable, just like you did
with do_add.
True, consider it done.
+ DECLARE_BITMAP(aprem, AP_DEVICES);
+ DECLARE_BITMAP(aqrem, AP_DOMAINS);
+ DECLARE_BITMAP(cdrem, AP_DOMAINS);
+ unsigned long *cur_apm, *cur_aqm, *cur_adm;
+ unsigned long *prev_apm, *prev_aqm, *prev_adm;
+
+ cur_apm = (unsigned long *)matrix_dev->config_info.apm;
+ cur_aqm = (unsigned long *)matrix_dev->config_info.aqm;
+ cur_adm = (unsigned long *)matrix_dev->config_info.adm;
+ prev_apm = (unsigned long *)matrix_dev->config_info_prev.apm;
+ prev_aqm = (unsigned long *)matrix_dev->config_info_prev.aqm;
+ prev_adm = (unsigned long *)matrix_dev->config_info_prev.adm;
+
+ ap_remove = bitmap_andnot(aprem, prev_apm, cur_apm, AP_DEVICES);
+ aq_remove = bitmap_andnot(aqrem, prev_aqm, cur_aqm, AP_DOMAINS);
+ cd_remove = bitmap_andnot(cdrem, prev_adm, cur_adm, AP_DOMAINS);
+
+ if (ap_remove || aq_remove || cd_remove)
+ vfio_ap_mdev_cfg_remove(aprem, aqrem, cdrem);
+}
...
+/**
+ * vfio_ap_on_cfg_changed - handles notification of changes to the
host AP
+ * configuration.
+ *
+ * @new_config_info: the new host AP configuration
+ * @old_config_info: the previous host AP configuration
+ */
+void vfio_ap_on_cfg_changed(struct ap_config_info *new_config_info,
+ struct ap_config_info *old_config_info)
+{
+ mutex_lock(&matrix_dev->guests_lock);
+
+ memcpy(&matrix_dev->config_info_prev, old_config_info,
+ sizeof(struct ap_config_info));
+ memcpy(&matrix_dev->config_info, new_config_info,
+ sizeof(struct ap_config_info));
Why are we storing old_config_info in the matrix_dev? It appears to only
be used within the functions called from right here. Why not just pass it
as an argument?
At the time I thought it might be valuable to keep around. I suppose it can
be passed to the functions that need it.
+ vfio_ap_mdev_on_cfg_remove();
+ vfio_ap_mdev_on_cfg_add();
+
+ mutex_unlock(&matrix_dev->guests_lock);
+}
Here is an idea to restructure things... consider combining logic from
vfio_ap_mdev_on_cfg_remove and vfio_ap_mdev_on_cfg_add with
vfio_ap_on_cfg_changed. This makes vfio_ap_on_cfg_changed() longer but
it eliminates some duplicated code and gets rid of both
vfio_ap_mdev_on_cfg_remove and vfio_ap_mdev_on_cfg_add.
note: Untested... :)
It seems like a lot of busy work for little gain. I prefer shorter
functions that
perform a specific task. Since we're solely in the realm of personal
preferences,
I'm going to leave this function as-is.
