s390/ap: handle outband SE bind state change

This patch addresses some weird scenarios where an outband
manipulation of the SE bind state of a queue assigned and
maybe in use by an SE guest with AP pass-through support
took place. So for example when the guest has bound and
associated a queue and then this domain has been zeroed on
the service element.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

3 files changed, 122 insertions, 50 deletions

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 20396eccb33b..f46dd6abacd7 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -1847,6 +1847,7 @@ static inline void ap_scan_domains(struct ap_card *ac)
 			aq->card = ac;
 			aq->config = !decfg;
 			aq->chkstop = chkstop;
+			aq->se_bstate = hwinfo.bs;
 			dev = &aq->ap_dev.device;
 			dev->bus = &ap_bus_type;
 			dev->parent = &ac->ap_dev.device;
@@ -1876,6 +1877,8 @@ static inline void ap_scan_domains(struct ap_card *ac)
 		}
 		/* handle state changes on already existing queue device */
 		spin_lock_bh(&aq->lock);
+		/* SE bind state */
+		aq->se_bstate = hwinfo.bs;
 		/* checkstop state */
 		if (chkstop && !aq->chkstop) {
 			/* checkstop on */
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index cc256424f70b..98814839ef30 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -194,7 +194,7 @@ struct ap_queue {
 	bool config;			/* configured state */
 	bool chkstop;			/* checkstop state */
 	ap_qid_t qid;			/* AP queue id. */
-	bool se_bound;			/* SE bound state */
+	unsigned int se_bstate;		/* SE bind state (BS) */
 	unsigned int assoc_idx;		/* SE association index */
 	int queue_count;		/* # messages currently on AP queue. */
 	int pendingq_count;		/* # requests on pendingq list. */
diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 39f250f1f1c3..682595443145 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -317,7 +317,6 @@ static enum ap_sm_wait ap_sm_reset(struct ap_queue *aq)
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		aq->sm_state = AP_SM_STATE_RESET_WAIT;
 		aq->rapq_fbit = 0;
-		aq->se_bound = false;
 		return AP_SM_WAIT_LOW_TIMEOUT;
 	default:
 		aq->dev_state = AP_DEV_STATE_ERROR;
@@ -338,17 +337,15 @@ static enum ap_sm_wait ap_sm_reset(struct ap_queue *aq)
 static enum ap_sm_wait ap_sm_reset_wait(struct ap_queue *aq)
 {
 	struct ap_queue_status status;
+	struct ap_tapq_hwinfo hwinfo;
 	void *lsi_ptr;
 
-	if (aq->queue_count > 0 && aq->reply)
-		/* Try to read a completed message and get the status */
-		status = ap_sm_recv(aq);
-	else
-		/* Get the status with TAPQ */
-		status = ap_tapq(aq->qid, NULL);
+	/* Get the status with TAPQ */
+	status = ap_test_queue(aq->qid, 1, &hwinfo);
 
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
+		aq->se_bstate = hwinfo.bs;
 		lsi_ptr = ap_airq_ptr();
 		if (lsi_ptr && ap_queue_enable_irq(aq, lsi_ptr) == 0)
 			aq->sm_state = AP_SM_STATE_SETIRQ_WAIT;
@@ -441,6 +438,9 @@ static enum ap_sm_wait ap_sm_assoc_wait(struct ap_queue *aq)
 		return AP_SM_WAIT_NONE;
 	}
 
+	/* update queue's SE bind state */
+	aq->se_bstate = hwinfo.bs;
+
 	/* check bs bits */
 	switch (hwinfo.bs) {
 	case AP_BS_Q_USABLE:
@@ -851,6 +851,12 @@ static ssize_t se_bind_show(struct device *dev,
 			   AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
 		return -EIO;
 	}
+
+	/* update queue's SE bind state */
+	spin_lock_bh(&aq->lock);
+	aq->se_bstate = hwinfo.bs;
+	spin_unlock_bh(&aq->lock);
+
 	switch (hwinfo.bs) {
 	case AP_BS_Q_USABLE:
 	case AP_BS_Q_USABLE_NO_SECURE_KEY:
@@ -866,6 +872,7 @@ static ssize_t se_bind_store(struct device *dev,
 {
 	struct ap_queue *aq = to_ap_queue(dev);
 	struct ap_queue_status status;
+	struct ap_tapq_hwinfo hwinfo;
 	bool value;
 	int rc;
 
@@ -877,39 +884,80 @@ static ssize_t se_bind_store(struct device *dev,
 	if (rc)
 		return rc;
 
-	if (value) {
-		/* bind, do BAPQ */
-		spin_lock_bh(&aq->lock);
-		if (aq->sm_state < AP_SM_STATE_IDLE) {
-			spin_unlock_bh(&aq->lock);
-			return -EBUSY;
-		}
-		status = ap_bapq(aq->qid);
-		spin_unlock_bh(&aq->lock);
-		if (!status.response_code) {
-			aq->se_bound = true;
-			AP_DBF_INFO("%s bapq(0x%02x.%04x) success\n", __func__,
-				    AP_QID_CARD(aq->qid),
-				    AP_QID_QUEUE(aq->qid));
-		} else {
-			AP_DBF_WARN("%s RC 0x%02x on bapq(0x%02x.%04x)\n",
-				    __func__, status.response_code,
-				    AP_QID_CARD(aq->qid),
-				    AP_QID_QUEUE(aq->qid));
-			return -EIO;
-		}
-	} else {
-		/* unbind, set F bit arg and trigger RAPQ */
+	if (!value) {
+		/* Unbind. Set F bit arg and trigger RAPQ */
 		spin_lock_bh(&aq->lock);
 		__ap_flush_queue(aq);
 		aq->rapq_fbit = 1;
-		aq->assoc_idx = ASSOC_IDX_INVALID;
-		aq->sm_state = AP_SM_STATE_RESET_START;
-		ap_wait(ap_sm_event(aq, AP_SM_EVENT_POLL));
-		spin_unlock_bh(&aq->lock);
+		_ap_queue_init_state(aq);
+		rc = count;
+		goto out;
 	}
 
-	return count;
+	/* Bind. Check current SE bind state */
+	status = ap_test_queue(aq->qid, 1, &hwinfo);
+	if (status.response_code) {
+		AP_DBF_WARN("%s RC 0x%02x on tapq(0x%02x.%04x)\n",
+			    __func__, status.response_code,
+			    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+		return -EIO;
+	}
+
+	/* Update BS state */
+	spin_lock_bh(&aq->lock);
+	aq->se_bstate = hwinfo.bs;
+	if (hwinfo.bs != AP_BS_Q_AVAIL_FOR_BINDING) {
+		AP_DBF_WARN("%s bind attempt with bs %d on queue 0x%02x.%04x\n",
+			    __func__, hwinfo.bs,
+			    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+		rc = -EINVAL;
+		goto out;
+	}
+
+	/* Check SM state */
+	if (aq->sm_state < AP_SM_STATE_IDLE) {
+		rc = -EBUSY;
+		goto out;
+	}
+
+	/* invoke BAPQ */
+	status = ap_bapq(aq->qid);
+	if (status.response_code) {
+		AP_DBF_WARN("%s RC 0x%02x on bapq(0x%02x.%04x)\n",
+			    __func__, status.response_code,
+			    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+		rc = -EIO;
+		goto out;
+	}
+	aq->assoc_idx = ASSOC_IDX_INVALID;
+
+	/* verify SE bind state */
+	status = ap_test_queue(aq->qid, 1, &hwinfo);
+	if (status.response_code) {
+		AP_DBF_WARN("%s RC 0x%02x on tapq(0x%02x.%04x)\n",
+			    __func__, status.response_code,
+			    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+		rc = -EIO;
+		goto out;
+	}
+	aq->se_bstate = hwinfo.bs;
+	if (!(hwinfo.bs == AP_BS_Q_USABLE ||
+	      hwinfo.bs == AP_BS_Q_USABLE_NO_SECURE_KEY)) {
+		AP_DBF_WARN("%s BAPQ success, but bs shows %d on queue 0x%02x.%04x\n",
+			    __func__, hwinfo.bs,
+			    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+		rc = -EIO;
+		goto out;
+	}
+
+	/* SE bind was successful */
+	AP_DBF_INFO("%s bapq(0x%02x.%04x) success\n", __func__,
+		    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+	rc = count;
+
+out:
+	spin_unlock_bh(&aq->lock);
+	return rc;
 }
 
 static DEVICE_ATTR_RW(se_bind);
@@ -932,6 +980,11 @@ static ssize_t se_associate_show(struct device *dev,
 		return -EIO;
 	}
 
+	/* update queue's SE bind state */
+	spin_lock_bh(&aq->lock);
+	aq->se_bstate = hwinfo.bs;
+	spin_unlock_bh(&aq->lock);
+
 	switch (hwinfo.bs) {
 	case AP_BS_Q_USABLE:
 		if (aq->assoc_idx == ASSOC_IDX_INVALID) {
@@ -954,6 +1007,7 @@ static ssize_t se_associate_store(struct device *dev,
 {
 	struct ap_queue *aq = to_ap_queue(dev);
 	struct ap_queue_status status;
+	struct ap_tapq_hwinfo hwinfo;
 	unsigned int value;
 	int rc;
 
@@ -967,18 +1021,28 @@ static ssize_t se_associate_store(struct device *dev,
 	if (value >= ASSOC_IDX_INVALID)
 		return -EINVAL;
 
+	/* check current SE bind state */
+	status = ap_test_queue(aq->qid, 1, &hwinfo);
+	if (status.response_code) {
+		AP_DBF_WARN("%s RC 0x%02x on tapq(0x%02x.%04x)\n",
+			    __func__, status.response_code,
+			    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+		return -EIO;
+	}
 	spin_lock_bh(&aq->lock);
-
-	/* sm should be in idle state */
-	if (aq->sm_state != AP_SM_STATE_IDLE) {
-		spin_unlock_bh(&aq->lock);
-		return -EBUSY;
+	aq->se_bstate = hwinfo.bs;
+	if (hwinfo.bs != AP_BS_Q_USABLE_NO_SECURE_KEY) {
+		AP_DBF_WARN("%s association attempt with bs %d on queue 0x%02x.%04x\n",
+			    __func__, hwinfo.bs,
+			    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+		rc = -EINVAL;
+		goto out;
 	}
 
-	/* already associated or association pending ? */
-	if (aq->assoc_idx != ASSOC_IDX_INVALID) {
-		spin_unlock_bh(&aq->lock);
-		return -EINVAL;
+	/* check SM state */
+	if (aq->sm_state != AP_SM_STATE_IDLE) {
+		rc = -EBUSY;
+		goto out;
 	}
 
 	/* trigger the asynchronous association request */
@@ -989,17 +1053,20 @@ static ssize_t se_associate_store(struct device *dev,
 		aq->sm_state = AP_SM_STATE_ASSOC_WAIT;
 		aq->assoc_idx = value;
 		ap_wait(ap_sm_event(aq, AP_SM_EVENT_POLL));
-		spin_unlock_bh(&aq->lock);
 		break;
 	default:
-		spin_unlock_bh(&aq->lock);
 		AP_DBF_WARN("%s RC 0x%02x on aapq(0x%02x.%04x)\n",
 			    __func__, status.response_code,
 			    AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
-		return -EIO;
+		rc = -EIO;
+		goto out;
 	}
 
-	return count;
+	rc = count;
+
+out:
+	spin_unlock_bh(&aq->lock);
+	return rc;
 }
 
 static DEVICE_ATTR_RW(se_associate);
@@ -1122,7 +1189,9 @@ bool ap_queue_usable(struct ap_queue *aq)
 	}
 
 	/* SE guest's queues additionally need to be bound */
-	if (ap_q_needs_bind(aq) && !aq->se_bound)
+	if (ap_q_needs_bind(aq) &&
+	    !(aq->se_bstate == AP_BS_Q_USABLE ||
+	      aq->se_bstate == AP_BS_Q_USABLE_NO_SECURE_KEY))
 		rc = false;
 
 unlock_and_out: