From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:33040 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726126AbgIRRCn (ORCPT ); Fri, 18 Sep 2020 13:02:43 -0400 From: Tony Krowiak Subject: [PATCH] s390/vfio-ap: fix unregister GISC when KVM is already gone results in OOPS Date: Fri, 18 Sep 2020 13:02:34 -0400 Message-Id: <20200918170234.5807-1-akrowiak@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-ID: To: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: pmorel@linux.ibm.com, pasic@linux.ibm.com, alex.williamson@redhat.com, cohuck@redhat.com, kwankhede@nvidia.com, borntraeger@de.ibm.com, Tony Krowiak 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 --- 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