This patch implements two new AP driver callbacks:
void (*on_config_changed)(struct ap_config_info *new_config_info,
struct ap_config_info *old_config_info);
void (*on_scan_complete)(struct ap_config_info *new_config_info,
struct ap_config_info *old_config_info);
The on_config_changed callback is invoked at the start of the AP bus scan
function when it determines that the host AP configuration information
has changed since the previous scan.
The vfio_ap device driver registers a callback function for this callback
that performs the following operations:
1. Unplugs the adapters, domains and control domains removed from the
host's AP configuration from the guests to which they are
assigned in a single operation.
2. Stores bitmaps identifying the adapters, domains and control domains
added to the host's AP configuration with the structure representing
the mediated device. When the vfio_ap device driver's probe callback is
subsequently invoked, the probe function will recognize that the
queue is being probed due to a change in the host's AP configuration
and the plugging of the queue into the guest will be bypassed.
The on_scan_complete callback is invoked after the ap bus scan is
completed if the host AP configuration data has changed. The vfio_ap
device driver registers a callback function for this callback that hot
plugs each queue and control domain added to the AP configuration for each
guest using them in a single hot plug operation.
Signed-off-by: Tony Krowiak <[email protected]>
---
drivers/s390/crypto/vfio_ap_drv.c | 4 +-
drivers/s390/crypto/vfio_ap_ops.c | 347 ++++++++++++++++++++++++--
drivers/s390/crypto/vfio_ap_private.h | 15 +-
3 files changed, 338 insertions(+), 28 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
index c4f0e28b1e91..711d5f2645b8 100644
--- a/drivers/s390/crypto/vfio_ap_drv.c
+++ b/drivers/s390/crypto/vfio_ap_drv.c
@@ -104,6 +104,8 @@ static struct ap_driver vfio_ap_drv = {
.probe = vfio_ap_mdev_probe_queue,
.remove = vfio_ap_mdev_remove_queue,
.in_use = vfio_ap_mdev_resource_in_use,
+ .on_config_changed = vfio_ap_on_cfg_changed,
+ .on_scan_complete = vfio_ap_on_scan_complete,
.ids = ap_queue_ids,
};
@@ -151,7 +153,7 @@ static int vfio_ap_matrix_dev_create(void)
/* Fill in config info via PQAP(QCI), if available */
if (test_facility(12)) {
- ret = ap_qci(&matrix_dev->info);
+ ret = ap_qci(&matrix_dev->config_info);
if (ret)
goto matrix_alloc_err;
}
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 02f75c4207b0..3304088d1012 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -333,7 +333,7 @@ static bool vfio_ap_mdev_filter_cdoms(struct ap_matrix_mdev *matrix_mdev)
bitmap_copy(shadow_adm, matrix_mdev->shadow_apcb.adm, AP_DOMAINS);
bitmap_and(matrix_mdev->shadow_apcb.adm, matrix_mdev->matrix.adm,
- (unsigned long *)matrix_dev->info.adm, AP_DOMAINS);
+ (unsigned long *)matrix_dev->config_info.adm, AP_DOMAINS);
return !bitmap_equal(shadow_adm, matrix_mdev->shadow_apcb.adm,
AP_DOMAINS);
@@ -353,19 +353,15 @@ static bool vfio_ap_mdev_filter_cdoms(struct ap_matrix_mdev *matrix_mdev)
static bool vfio_ap_mdev_filter_matrix(unsigned long *apm, unsigned long *aqm,
struct ap_matrix_mdev *matrix_mdev)
{
- int ret;
unsigned long apid, apqi, apqn;
DECLARE_BITMAP(shadow_apm, AP_DEVICES);
DECLARE_BITMAP(shadow_aqm, AP_DOMAINS);
struct vfio_ap_queue *q;
- ret = ap_qci(&matrix_dev->info);
- if (ret)
- return false;
-
bitmap_copy(shadow_apm, matrix_mdev->shadow_apcb.apm, AP_DEVICES);
bitmap_copy(shadow_aqm, matrix_mdev->shadow_apcb.aqm, AP_DOMAINS);
- vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_apcb);
+ vfio_ap_matrix_init(&matrix_dev->config_info,
+ &matrix_mdev->shadow_apcb);
/*
* Copy the adapters, domains and control domains to the shadow_apcb
@@ -373,9 +369,9 @@ static bool vfio_ap_mdev_filter_matrix(unsigned long *apm, unsigned long *aqm,
* AP configuration.
*/
bitmap_and(matrix_mdev->shadow_apcb.apm, matrix_mdev->matrix.apm,
- (unsigned long *)matrix_dev->info.apm, AP_DEVICES);
+ (unsigned long *)matrix_dev->config_info.apm, AP_DEVICES);
bitmap_and(matrix_mdev->shadow_apcb.aqm, matrix_mdev->matrix.aqm,
- (unsigned long *)matrix_dev->info.aqm, AP_DOMAINS);
+ (unsigned long *)matrix_dev->config_info.aqm, AP_DOMAINS);
for_each_set_bit_inv(apid, apm, AP_DEVICES) {
for_each_set_bit_inv(apqi, aqm, AP_DOMAINS) {
@@ -389,6 +385,7 @@ static bool vfio_ap_mdev_filter_matrix(unsigned long *apm, unsigned long *aqm,
*/
apqn = AP_MKQID(apid, apqi);
q = vfio_ap_mdev_get_queue(matrix_mdev, apqn);
+
if (!q || q->reset_rc) {
clear_bit_inv(apid,
matrix_mdev->shadow_apcb.apm);
@@ -420,9 +417,10 @@ static int vfio_ap_mdev_probe(struct mdev_device *mdev)
&vfio_ap_matrix_dev_ops);
matrix_mdev->mdev = mdev;
- vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
+ vfio_ap_matrix_init(&matrix_dev->config_info, &matrix_mdev->matrix);
+ vfio_ap_matrix_init(&matrix_dev->config_info,
+ &matrix_mdev->shadow_apcb);
matrix_mdev->pqap_hook = handle_pqap;
- vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_apcb);
hash_init(matrix_mdev->qtable.queues);
mdev_set_drvdata(mdev, matrix_mdev);
mutex_lock(&matrix_dev->guests_lock);
@@ -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);
+ }
+ }
}
/**
@@ -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 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
* 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);
}
}
@@ -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;
+
+ if (!bitmap_empty(aprem, AP_DEVICES)) {
+ do_hotplug |= bitmap_andnot(matrix_mdev->shadow_apcb.apm,
+ matrix_mdev->shadow_apcb.apm,
+ aprem, AP_DEVICES);
+ }
+
+ 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.
+ */
+static void vfio_ap_mdev_cfg_remove(unsigned long *ap_remove,
+ unsigned long *aq_remove,
+ unsigned long *cd_remove)
+{
+ struct ap_matrix_mdev *matrix_mdev;
+ DECLARE_BITMAP(aprem, AP_DEVICES);
+ DECLARE_BITMAP(aqrem, AP_DOMAINS);
+ DECLARE_BITMAP(cdrem, AP_DOMAINS);
+ int do_ap_remove, do_aq_remove, do_cd_remove;
+
+ list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+ if (!matrix_mdev->kvm)
+ continue;
+
+ mutex_lock(&matrix_mdev->kvm->lock);
+ mutex_lock(&matrix_dev->mdevs_lock);
+
+ do_ap_remove = bitmap_and(aprem, ap_remove,
+ matrix_mdev->matrix.apm,
+ AP_DEVICES);
+ do_aq_remove = bitmap_and(aqrem, aq_remove,
+ matrix_mdev->matrix.aqm,
+ AP_DOMAINS);
+ do_cd_remove = bitmap_andnot(cdrem, cd_remove,
+ matrix_mdev->matrix.adm,
+ AP_DOMAINS);
+
+ if (do_ap_remove || do_aq_remove || do_cd_remove)
+ vfio_ap_mdev_hot_unplug_cfg(matrix_mdev, aprem, aqrem,
+ cdrem);
+
+ mutex_unlock(&matrix_dev->mdevs_lock);
+ mutex_unlock(&matrix_mdev->kvm->lock);
+ }
+}
+
+/**
+ * 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;
+ 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_mdev_cfg_add - store bitmaps specifying the adapters, domains and
+ * control domains that have been added to the host's
+ * AP configuration for each matrix mdev to which they
+ * are assigned.
+ *
+ * @apm_add: a bitmap specifying the adapters that have been added to the AP
+ * configuration.
+ * @aqm_add: a bitmap specifying the domains that have been added to the AP
+ * configuration.
+ * @adm_add: a bitmap specifying the control domains that have been added to the
+ * AP configuration.
+ */
+static void vfio_ap_mdev_cfg_add(unsigned long *apm_add, unsigned long *aqm_add,
+ unsigned long *adm_add)
+{
+ struct ap_matrix_mdev *matrix_mdev;
+
+ list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+ bitmap_and(matrix_mdev->apm_add,
+ matrix_mdev->matrix.apm, apm_add, AP_DEVICES);
+ bitmap_and(matrix_mdev->aqm_add,
+ matrix_mdev->matrix.aqm, aqm_add, AP_DOMAINS);
+ bitmap_and(matrix_mdev->adm_add,
+ matrix_mdev->matrix.adm, adm_add, AP_DEVICES);
+ }
+}
+
+/**
+ * vfio_ap_mdev_on_cfg_add - responds to the addition of adapters, domains and
+ * control domains to the host AP configuration
+ * by updating the bitmaps that specify what adapters,
+ * domains and control domains have been added so they
+ * can be hot plugged into the guest when the AP bus
+ * scan completes (see vfio_ap_on_scan_complete
+ * function).
+ */
+static void vfio_ap_mdev_on_cfg_add(void)
+{
+ bool do_add;
+ DECLARE_BITMAP(apm_add, AP_DEVICES);
+ DECLARE_BITMAP(aqm_add, AP_DOMAINS);
+ DECLARE_BITMAP(adm_add, 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;
+
+ do_add = bitmap_andnot(apm_add, cur_apm, prev_apm, AP_DEVICES);
+ do_add |= bitmap_andnot(aqm_add, cur_aqm, prev_aqm, AP_DOMAINS);
+ do_add |= bitmap_andnot(adm_add, cur_adm, prev_adm, AP_DOMAINS);
+
+ if (do_add)
+ vfio_ap_mdev_cfg_add(apm_add, aqm_add, adm_add);
+}
+
+/**
+ * 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));
+ vfio_ap_mdev_on_cfg_remove();
+ vfio_ap_mdev_on_cfg_add();
+
+ mutex_unlock(&matrix_dev->guests_lock);
+}
+
+static void vfio_ap_mdev_hot_plug_cfg(struct ap_matrix_mdev *matrix_mdev)
+{
+// bool filter_matrix, filter_cdoms, do_hotplug = false;
+ bool do_hotplug = false;
+ bool filter_domains = false;
+ bool filter_adapters = false;
+ DECLARE_BITMAP(apm, AP_DEVICES);
+ DECLARE_BITMAP(aqm, AP_DOMAINS);
+
+ mutex_lock(&matrix_mdev->kvm->lock);
+ mutex_lock(&matrix_dev->mdevs_lock);
+
+ filter_adapters = bitmap_and(apm, matrix_mdev->matrix.apm,
+ matrix_mdev->apm_add, AP_DEVICES);
+ filter_domains = bitmap_and(aqm, matrix_mdev->matrix.aqm,
+ matrix_mdev->aqm_add, AP_DOMAINS);
+
+ if (filter_adapters && filter_domains)
+ do_hotplug |= vfio_ap_mdev_filter_matrix(apm, aqm, matrix_mdev);
+ else if (filter_adapters)
+ do_hotplug |=
+ vfio_ap_mdev_filter_matrix(apm,
+ matrix_mdev->shadow_apcb.aqm,
+ matrix_mdev);
+ else
+ do_hotplug |=
+ vfio_ap_mdev_filter_matrix(matrix_mdev->shadow_apcb.apm,
+ aqm, matrix_mdev);
+
+ if (bitmap_intersects(matrix_mdev->matrix.adm, matrix_mdev->adm_add,
+ AP_DOMAINS))
+ do_hotplug |= vfio_ap_mdev_filter_cdoms(matrix_mdev);
+
+ if (do_hotplug)
+ vfio_ap_mdev_hotplug_apcb(matrix_mdev);
+
+ mutex_unlock(&matrix_dev->mdevs_lock);
+ mutex_unlock(&matrix_mdev->kvm->lock);
+}
+
+void vfio_ap_on_scan_complete(struct ap_config_info *new_config_info,
+ struct ap_config_info *old_config_info)
+{
+ struct ap_matrix_mdev *matrix_mdev;
+
+ mutex_lock(&matrix_dev->guests_lock);
+
+ list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
+ if (bitmap_empty(matrix_mdev->apm_add, AP_DEVICES) &&
+ bitmap_empty(matrix_mdev->aqm_add, AP_DOMAINS) &&
+ bitmap_empty(matrix_mdev->adm_add, AP_DOMAINS))
+ continue;
+
+ vfio_ap_mdev_hot_plug_cfg(matrix_mdev);
+ bitmap_clear(matrix_mdev->apm_add, 0, AP_DEVICES);
+ bitmap_clear(matrix_mdev->aqm_add, 0, AP_DOMAINS);
+ bitmap_clear(matrix_mdev->adm_add, 0, AP_DOMAINS);
+ }
+
+ mutex_unlock(&matrix_dev->guests_lock);
+}
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index e30f171f89ec..a7fe4a3cf896 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -31,7 +31,9 @@
*
* @device: generic device structure associated with the AP matrix device
* @available_instances: number of mediated matrix devices that can be created
- * @info: the struct containing the output from the PQAP(QCI) instruction
+ * @config_info: the object containing the current AP configuration for the host
+ * @config_info_prev: the object containing the previous AP configuration for
+ * Gthe host
* @mdev_list: the list of mediated matrix devices created
* @mdevs_lock: mutex for locking the ap_matrix_mdev devices under the control
* of the vfio_ap device driver. This lock will be taken every time
@@ -47,7 +49,8 @@
struct ap_matrix_dev {
struct device device;
atomic_t available_instances;
- struct ap_config_info info;
+ struct ap_config_info config_info;
+ struct ap_config_info config_info_prev;
struct list_head mdev_list;
struct mutex mdevs_lock;
struct ap_driver *vfio_ap_drv;
@@ -118,6 +121,9 @@ struct ap_matrix_mdev {
crypto_hook pqap_hook;
struct mdev_device *mdev;
struct ap_queue_table qtable;
+ DECLARE_BITMAP(apm_add, AP_DEVICES);
+ DECLARE_BITMAP(aqm_add, AP_DOMAINS);
+ DECLARE_BITMAP(adm_add, AP_DOMAINS);
};
/**
@@ -148,4 +154,9 @@ void vfio_ap_mdev_remove_queue(struct ap_device *queue);
int vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm);
+void vfio_ap_on_cfg_changed(struct ap_config_info *new_config_info,
+ struct ap_config_info *old_config_info);
+void vfio_ap_on_scan_complete(struct ap_config_info *new_config_info,
+ struct ap_config_info *old_config_info);
+
#endif /* _VFIO_AP_PRIVATE_H_ */
--
2.31.1
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?
> /**
> @@ -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.
> * 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.
> * 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...?
>
> @@ -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.
> + 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.
> + }
> +
> + 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.
> + 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?
> + 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... :)
void vfio_ap_on_cfg_changed(struct ap_config_info *new_config_info,
struct ap_config_info *old_config_info)
{
DECLARE_BITMAP(changed_adapters, AP_DEVICES);
DECLARE_BITMAP(changed_domains, AP_DOMAINS);
DECLARE_BITMAP(changed_cdoms, AP_DOMAINS);
unsigned long *cur_apm, *cur_aqm, *cur_adm;
unsigned long *prev_apm, *prev_aqm, *prev_adm;
cur_apm = (unsigned long *)new_config_info->apm;
cur_aqm = (unsigned long *)new_config_info->aqm;
cur_adm = (unsigned long *)new_config_info->adm;
prev_apm = (unsigned long *)old_config_info->apm;
prev_aqm = (unsigned long *)old_config_info->.aqm;
prev_adm = (unsigned long *)old_config_info->adm;
mutex_lock(&matrix_dev->guests_lock);
/* Handle host configuration removals */
bitmap_andnot(changed_adapters, prev_apm, cur_apm, AP_DEVICES);
bitmap_andnot(changed_domains, prev_aqm, cur_aqm, AP_DOMAINS);
bitmap_andnot(changed_cdoms, prev_adm, cur_adm, AP_DOMAINS);
if (changed_adapters || changed_domains || changed_cdoms)
vfio_ap_mdev_cfg_remove(aprem, aqrem, cdrem);
bitmap_clear(changed_adapters, 0, AP_DEVICES);
bitmap_clear(changed_domains, 0, AP_DOMAINS);
bitmap_clear(changed_cdoms, 0, AP_DOMAINS);
/* Handle host configuration additions */
bitmap_andnot(changed_adapters, cur_apm, prev_apm, AP_DEVICES);
bitmap_andnot(changed_domains, cur_aqm, prev_aqm, AP_DOMAINS);
bitmap_andnot(changed_cdoms, cur_adm, prev_adm, AP_DOMAINS);
if (changed_adapters || changed_domains || changed_cdoms) {
vfio_ap_mdev_cfg_add(apm_add, aqm_add, adm_add);
}
mutex_unlock(&matrix_dev->guests_lock);
}
Not sure if where I put the locking is 100% correct. We could do a
lock/unlock around each call to vfio_ap_mdev_cfg_{remove|add} but
there is probablyt no point to that, right?
Also, a side effect of these changes is that matrix_dev->config_info
is no longer updated. I guess we either would need to update it here
or update it wherever it was originally updated before this patrch.
--
-- Jason J. Herne ([email protected])
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.