From 5c4c2126fb69812e6e62a7d8bfaac308a3ddeec7 Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Fri, 5 Jul 2019 21:02:48 +0200
Subject: [PATCH] s390: vfio-ap: fix irq registration
vfio_ap_free_aqic_resources is called in two places:
- during registration to have a "known state"
- during interrupt disable
We must not clear q->matrix_mdev in the registration phase as this will
mess up the reference counting and can lead to some warning and other
bugs.
Fixes: ec89b55e3bce ("s390: ap: implement PAPQ AQIC interception in kernel")
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 2c9fb1423a395..0468ad72c4656 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -115,7 +115,6 @@ static void vfio_ap_wait_for_irqclear(int apqn)
* Unregisters the ISC in the GIB when the saved ISC not invalid.
* Unpin the guest's page holding the NIB when it exist.
* Reset the saved_pfn and saved_isc to invalid values.
- * Clear the pointer to the matrix mediated device.
*
*/
static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
@@ -127,7 +126,6 @@ static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
&q->saved_pfn, 1);
q->saved_pfn = 0;
q->saved_isc = VFIO_AP_ISC_INVALID;
- q->matrix_mdev = NULL;
}
/**
@@ -179,6 +177,7 @@ struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q)
status.response_code);
end_free:
vfio_ap_free_aqic_resources(q);
+ q->matrix_mdev = NULL;
return status;
}
--
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