[PATCH v18 07/18] s390/vfio-ap: refresh guest's APCB by filtering APQNs assigned to mdev

[Tony Krowiak <akrowiak@linux.ibm.com>]

Refresh the guest's APCB by filtering the APQNs assigned to the matrix mdev
that do not reference an AP queue device bound to the vfio_ap device
driver. The mdev's APQNs will be filtered according to the following rules:

* The APID of each adapter and the APQI of each domain that is not in the
host's AP configuration is filtered out.

* The APID of each adapter comprising an APQN that does not reference a
queue device bound to the vfio_ap device driver is filtered. The APQNs
are derived from the Cartesian product of the APID of each adapter and
APQI of each domain assigned to the mdev.

The control domains that are not assigned to the host's AP configuration
will also be filtered before assigning them to the guest's APCB.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
---
 drivers/s390/crypto/vfio_ap_ops.c | 96 ++++++++++++++++++++++++++++++-
 1 file changed, 93 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 4b676a55f203..b67b2f0faeea 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -317,6 +317,63 @@ static void vfio_ap_matrix_init(struct ap_config_info *info,
 	matrix->adm_max = info->apxa ? info->Nd : 15;
 }
 
+static void vfio_ap_mdev_filter_cdoms(struct ap_matrix_mdev *matrix_mdev)
+{
+	bitmap_and(matrix_mdev->shadow_apcb.adm, matrix_mdev->matrix.adm,
+		   (unsigned long *)matrix_dev->info.adm, AP_DOMAINS);
+}
+
+/*
+ * vfio_ap_mdev_filter_matrix - copy the mdev's AP configuration to the KVM
+ *				guest's APCB then filter the APIDs that do not
+ *				comprise at least one APQN that references a
+ *				queue device bound to the vfio_ap device driver.
+ *
+ * @matrix_mdev: the mdev whose AP configuration is to be filtered.
+ */
+static void vfio_ap_mdev_filter_matrix(unsigned long *apm, unsigned long *aqm,
+				       struct ap_matrix_mdev *matrix_mdev)
+{
+	int ret;
+	unsigned long apid, apqi, apqn;
+
+	ret = ap_qci(&matrix_dev->info);
+	if (ret)
+		return;
+
+	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_apcb);
+
+	/*
+	 * Copy the adapters, domains and control domains to the shadow_apcb
+	 * from the matrix mdev, but only those that are assigned to the host's
+	 * AP configuration.
+	 */
+	bitmap_and(matrix_mdev->shadow_apcb.apm, matrix_mdev->matrix.apm,
+		   (unsigned long *)matrix_dev->info.apm, AP_DEVICES);
+	bitmap_and(matrix_mdev->shadow_apcb.aqm, matrix_mdev->matrix.aqm,
+		   (unsigned long *)matrix_dev->info.aqm, AP_DOMAINS);
+
+	for_each_set_bit_inv(apid, apm, AP_DEVICES) {
+		for_each_set_bit_inv(apqi, aqm, AP_DOMAINS) {
+			/*
+			 * If the APQN is not bound to the vfio_ap device
+			 * driver, then we can't assign it to the guest's
+			 * AP configuration. The AP architecture won't
+			 * allow filtering of a single APQN, so let's filter
+			 * the APID since an adapter represents a physical
+			 * hardware device.
+			 */
+			apqn = AP_MKQID(apid, apqi);
+
+			if (!vfio_ap_mdev_get_queue(matrix_mdev, apqn)) {
+				clear_bit_inv(apid,
+					      matrix_mdev->shadow_apcb.apm);
+				break;
+			}
+		}
+	}
+}
+
 static int vfio_ap_mdev_probe(struct mdev_device *mdev)
 {
 	struct ap_matrix_mdev *matrix_mdev;
@@ -672,6 +729,8 @@ static ssize_t assign_adapter_store(struct device *dev,
 {
 	int ret;
 	unsigned long apid;
+	DECLARE_BITMAP(apm, AP_DEVICES);
+
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
 
 	mutex_lock(&matrix_dev->lock);
@@ -701,12 +760,15 @@ static ssize_t assign_adapter_store(struct device *dev,
 		goto done;
 
 	set_bit_inv(apid, matrix_mdev->matrix.apm);
+	memset(apm, 0, sizeof(apm));
+	set_bit_inv(apid, apm);
 
 	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
 	if (ret)
 		goto share_err;
 
 	vfio_ap_mdev_link_adapter(matrix_mdev, apid);
+	vfio_ap_mdev_filter_matrix(apm, matrix_mdev->matrix.aqm, matrix_mdev);
 	ret = count;
 	goto done;
 
@@ -775,6 +837,10 @@ static ssize_t unassign_adapter_store(struct device *dev,
 
 	clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
 	vfio_ap_mdev_unlink_adapter(matrix_mdev, apid);
+
+	if (test_bit_inv(apid, matrix_mdev->shadow_apcb.apm))
+		clear_bit_inv(apid, matrix_mdev->shadow_apcb.apm);
+
 	ret = count;
 done:
 	mutex_unlock(&matrix_dev->lock);
@@ -848,6 +914,7 @@ static ssize_t assign_domain_store(struct device *dev,
 {
 	int ret;
 	unsigned long apqi;
+	DECLARE_BITMAP(aqm, AP_DOMAINS);
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
 	unsigned long max_apqi = matrix_mdev->matrix.aqm_max;
 
@@ -872,12 +939,15 @@ static ssize_t assign_domain_store(struct device *dev,
 		goto done;
 
 	set_bit_inv(apqi, matrix_mdev->matrix.aqm);
+	memset(aqm, 0, sizeof(aqm));
+	set_bit_inv(apqi, aqm);
 
 	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
 	if (ret)
 		goto share_err;
 
 	vfio_ap_mdev_link_domain(matrix_mdev, apqi);
+	vfio_ap_mdev_filter_matrix(matrix_mdev->matrix.apm, aqm, matrix_mdev);
 	ret = count;
 	goto done;
 
@@ -946,6 +1016,10 @@ static ssize_t unassign_domain_store(struct device *dev,
 
 	clear_bit_inv((unsigned long)apqi, matrix_mdev->matrix.aqm);
 	vfio_ap_mdev_unlink_domain(matrix_mdev, apqi);
+
+	if (test_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm))
+		clear_bit_inv(apqi, matrix_mdev->shadow_apcb.aqm);
+
 	ret = count;
 
 done:
@@ -999,6 +1073,7 @@ static ssize_t assign_control_domain_store(struct device *dev,
 	 * number of control domains that can be assigned.
 	 */
 	set_bit_inv(id, matrix_mdev->matrix.adm);
+	vfio_ap_mdev_filter_cdoms(matrix_mdev);
 	ret = count;
 done:
 	mutex_unlock(&matrix_dev->lock);
@@ -1046,6 +1121,10 @@ static ssize_t unassign_control_domain_store(struct device *dev,
 	}
 
 	clear_bit_inv(domid, matrix_mdev->matrix.adm);
+
+	if (test_bit_inv(domid, matrix_mdev->shadow_apcb.adm))
+		clear_bit_inv(domid, matrix_mdev->shadow_apcb.adm);
+
 	ret = count;
 done:
 	mutex_unlock(&matrix_dev->lock);
@@ -1186,8 +1265,6 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
 
 		kvm_get_kvm(kvm);
 		matrix_mdev->kvm = kvm;
-		memcpy(&matrix_mdev->shadow_apcb, &matrix_mdev->matrix,
-		       sizeof(struct ap_matrix));
 		kvm_arch_crypto_set_masks(kvm, matrix_mdev->shadow_apcb.apm,
 					  matrix_mdev->shadow_apcb.aqm,
 					  matrix_mdev->shadow_apcb.adm);
@@ -1528,6 +1605,7 @@ static void vfio_ap_queue_link_mdev(struct vfio_ap_queue *q)
 int vfio_ap_mdev_probe_queue(struct ap_device *apdev)
 {
 	struct vfio_ap_queue *q;
+	DECLARE_BITMAP(apm, AP_DEVICES);
 
 	q = kzalloc(sizeof(*q), GFP_KERNEL);
 	if (!q)
@@ -1537,6 +1615,12 @@ int vfio_ap_mdev_probe_queue(struct ap_device *apdev)
 	q->apqn = to_ap_queue(&apdev->device)->qid;
 	q->saved_isc = VFIO_AP_ISC_INVALID;
 	vfio_ap_queue_link_mdev(q);
+	if (q->matrix_mdev) {
+		memset(apm, 0, sizeof(apm));
+		set_bit_inv(AP_QID_CARD(q->apqn), apm);
+		vfio_ap_mdev_filter_matrix(apm, q->matrix_mdev->matrix.aqm,
+					   q->matrix_mdev);
+	}
 	dev_set_drvdata(&apdev->device, q);
 	mutex_unlock(&matrix_dev->lock);
 
@@ -1545,14 +1629,20 @@ int vfio_ap_mdev_probe_queue(struct ap_device *apdev)
 
 void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
 {
+	unsigned long apid;
 	struct vfio_ap_queue *q;
 
 	mutex_lock(&matrix_dev->lock);
 	q = dev_get_drvdata(&apdev->device);
 
-	if (q->matrix_mdev)
+	if (q->matrix_mdev) {
 		vfio_ap_unlink_queue_fr_mdev(q);
 
+		apid = AP_QID_CARD(q->apqn);
+		if (test_bit_inv(apid, q->matrix_mdev->shadow_apcb.apm))
+			clear_bit_inv(apid, q->matrix_mdev->shadow_apcb.apm);
+	}
+
 	vfio_ap_mdev_reset_queue(q, 1);
 	dev_set_drvdata(&apdev->device, NULL);
 	kfree(q);
-- 
2.31.1