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From: Jason Gunthorpe <jgg@nvidia.com>
To: "Jason J. Herne" <jjherne@linux.ibm.com>
Cc: Tony Krowiak <akrowiak@linux.ibm.com>,
	linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
	borntraeger@de.ibm.com, cohuck@redhat.com,
	pasic@linux.vnet.ibm.com, alex.williamson@redhat.com,
	kwankhede@nvidia.com, frankja@linux.ibm.com, david@redhat.com,
	imbrenda@linux.ibm.com, hca@linux.ibm.com
Subject: Re: [PATCH] s390/vfio-ap: do not use open locks during VFIO_GROUP_NOTIFY_SET_KVM notification
Date: Wed, 30 Jun 2021 08:55:08 -0300	[thread overview]
Message-ID: <20210630115508.GB10820@nvidia.com> (raw)
In-Reply-To: <a37d2816-47fc-ef6b-eb59-c5782e13ca12@linux.ibm.com>

On Tue, Jun 29, 2021 at 09:21:31AM -0400, Jason J. Herne wrote:

> > +	mutex_lock(&matrix_dev->lock);
> > -	if (matrix_mdev->kvm) {
> > -		matrix_mdev->kvm_busy = true;
> > +	if ((matrix_mdev->kvm) && (matrix_mdev->kvm->arch.crypto.crycbd)) {
> >   		mutex_unlock(&matrix_dev->lock);
> 
> 
> If this function cannot be entered concurrently on separate threads then I
> think we can remove this mutex_unlock of matrix_dev->lock, 

Don't remove locking around data. If the data is written under a mutex
it should be read under a mutex too.

Jason

      reply	other threads:[~2021-06-30 11:55 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-25 22:07 [PATCH] s390/vfio-ap: do not use open locks during VFIO_GROUP_NOTIFY_SET_KVM notification Tony Krowiak
2021-06-28 17:34 ` Jason Gunthorpe
2021-06-28 18:20   ` Tony Krowiak
2021-06-28 18:22     ` Jason Gunthorpe
2021-06-28 18:27       ` Tony Krowiak
2021-06-28 20:29 ` Halil Pasic
2021-06-30 14:31   ` Tony Krowiak
2021-06-30 22:39     ` Halil Pasic
2021-07-01 14:28       ` Tony Krowiak
2021-07-05 14:13         ` Jason Gunthorpe
2021-07-06 13:39           ` Tony Krowiak
2021-07-06 13:49             ` Jason Gunthorpe
2021-07-06 22:43               ` Tony Krowiak
2021-06-29 13:21 ` Jason J. Herne
2021-06-30 11:55   ` Jason Gunthorpe [this message]

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