lkml.org 
[lkml]   [2020]   [Sep]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] s390/vfio-ap: fix unregister GISC when KVM is already gone results in OOPS
Date
Attempting to unregister Guest Interruption Subclass (GISC) when the
link between the matrix mdev and KVM has been removed results in the
following:

"Kernel panic -not syncing: Fatal exception: panic_on_oops"

This patch fixes this bug by verifying the matrix mdev and KVM are still
linked prior to unregistering the GISC.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index e0bde8518745..847a88642644 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -119,11 +119,15 @@ static void vfio_ap_wait_for_irqclear(int apqn)
*/
static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
{
- if (q->saved_isc != VFIO_AP_ISC_INVALID && q->matrix_mdev)
- kvm_s390_gisc_unregister(q->matrix_mdev->kvm, q->saved_isc);
- if (q->saved_pfn && q->matrix_mdev)
- vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev),
- &q->saved_pfn, 1);
+ if (q->matrix_mdev) {
+ if (q->saved_isc != VFIO_AP_ISC_INVALID && q->matrix_mdev->kvm)
+ kvm_s390_gisc_unregister(q->matrix_mdev->kvm,
+ q->saved_isc);
+ if (q->saved_pfn)
+ vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev),
+ &q->saved_pfn, 1);
+ }
+
q->saved_pfn = 0;
q->saved_isc = VFIO_AP_ISC_INVALID;
}
--
2.21.1
\
 
 \ /
  Last update: 2020-09-18 19:03    [W:0.126 / U:0.480 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site