On 2/19/21 8:45 AM, Cornelia Huck wrote:
On Mon, 15 Feb 2021 20:15:47 -0500 Tony Krowiak akrowiak@linux.ibm.com wrote:
This patch fixes a circular locking dependency in the CI introduced by commit f21916ec4826 ("s390/vfio-ap: clean up vfio_ap resources when KVM pointer invalidated"). The lockdep only occurs when starting a Secure Execution guest. Crypto virtualization (vfio_ap) is not yet supported for SE guests; however, in order to avoid CI errors, this fix is being provided.
The circular lockdep was introduced when the masks in the guest's APCB were taken under the matrix_dev->lock. While the lock is definitely needed to protect the setting/unsetting of the KVM pointer, it is not necessarily critical for setting the masks, so this will not be done under protection of the matrix_dev->lock.
Fixes: f21916ec4826 ("s390/vfio-ap: clean up vfio_ap resources when KVM pointer invalidated") Cc: stable@vger.kernel.org Signed-off-by: Tony Krowiak akrowiak@linux.ibm.com
drivers/s390/crypto/vfio_ap_ops.c | 119 +++++++++++++++++++++--------- 1 file changed, 84 insertions(+), 35 deletions(-)
I've been looking at the patch for a bit now and tried to follow down the various paths; and while I think it's ok, I do not really have enough confidence about that for a R-b. But have an
Acked-by: Cornelia Huck cohuck@redhat.com
Thanks for the review.