[lkml]   [2021]   [Feb]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v2 1/1] s390/vfio-ap: fix circular lockdep when setting/clearing crypto masks

On 2/19/21 8:45 AM, Cornelia Huck wrote:
> On Mon, 15 Feb 2021 20:15:47 -0500
> Tony Krowiak <> 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:
>> Signed-off-by: Tony Krowiak <>
>> ---
>> 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 <>

Thanks for the review.


 \ /
  Last update: 2021-02-19 21:51    [W:0.108 / U:3.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site