Searched hist:"86956 e70761b3292156d668e87126844334dd71b" (Results 1 – 3 of 3) sorted by relevance
| /openbmc/linux/drivers/s390/crypto/ |
| H A D | vfio_ap_private.h | diff 86956e70761b3292156d668e87126844334dd71b Mon Aug 23 16:20:47 CDT 2021 Tony Krowiak <akrowiak@linux.ibm.com> s390/vfio-ap: replace open coded locks for VFIO_GROUP_NOTIFY_SET_KVM notification
It was pointed out during an unrelated patch review that locks should not
be open coded - i.e., writing the algorithm of a standard lock in a
function instead of using a lock from the standard library. The setting and
testing of a busy flag and sleeping on a wait_event is the same thing
a lock does. The open coded locks are invisible to lockdep, so potential
locking problems are not detected.
This patch removes the open coded locks used during
VFIO_GROUP_NOTIFY_SET_KVM notification. The busy flag
and wait queue were introduced to resolve a possible circular locking
dependency reported by lockdep when starting a secure execution guest
configured with AP adapters and domains. Reversing the order in which
the kvm->lock mutex and matrix_dev->lock mutex are locked resolves the
issue reported by lockdep, thus enabling the removal of the open coded
locks.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/20210823212047.1476436-3-akrowiak@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
|
| H A D | vfio_ap_ops.c | diff 86956e70761b3292156d668e87126844334dd71b Mon Aug 23 16:20:47 CDT 2021 Tony Krowiak <akrowiak@linux.ibm.com> s390/vfio-ap: replace open coded locks for VFIO_GROUP_NOTIFY_SET_KVM notification
It was pointed out during an unrelated patch review that locks should not
be open coded - i.e., writing the algorithm of a standard lock in a
function instead of using a lock from the standard library. The setting and
testing of a busy flag and sleeping on a wait_event is the same thing
a lock does. The open coded locks are invisible to lockdep, so potential
locking problems are not detected.
This patch removes the open coded locks used during
VFIO_GROUP_NOTIFY_SET_KVM notification. The busy flag
and wait queue were introduced to resolve a possible circular locking
dependency reported by lockdep when starting a secure execution guest
configured with AP adapters and domains. Reversing the order in which
the kvm->lock mutex and matrix_dev->lock mutex are locked resolves the
issue reported by lockdep, thus enabling the removal of the open coded
locks.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/20210823212047.1476436-3-akrowiak@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
|
| /openbmc/linux/arch/s390/kvm/ |
| H A D | kvm-s390.c | diff 86956e70761b3292156d668e87126844334dd71b Mon Aug 23 16:20:47 CDT 2021 Tony Krowiak <akrowiak@linux.ibm.com> s390/vfio-ap: replace open coded locks for VFIO_GROUP_NOTIFY_SET_KVM notification
It was pointed out during an unrelated patch review that locks should not
be open coded - i.e., writing the algorithm of a standard lock in a
function instead of using a lock from the standard library. The setting and
testing of a busy flag and sleeping on a wait_event is the same thing
a lock does. The open coded locks are invisible to lockdep, so potential
locking problems are not detected.
This patch removes the open coded locks used during
VFIO_GROUP_NOTIFY_SET_KVM notification. The busy flag
and wait queue were introduced to resolve a possible circular locking
dependency reported by lockdep when starting a secure execution guest
configured with AP adapters and domains. Reversing the order in which
the kvm->lock mutex and matrix_dev->lock mutex are locked resolves the
issue reported by lockdep, thus enabling the removal of the open coded
locks.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/20210823212047.1476436-3-akrowiak@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
|