From: Jason Gunthorpe <jgg@nvidia.com>
To: Matthew Rosato <mjrosato@linux.ibm.com>
Cc: akrowiak@linux.ibm.com, jjherne@linux.ibm.com,
farman@linux.ibm.com, imbrenda@linux.ibm.com,
frankja@linux.ibm.com, pmorel@linux.ibm.com, david@redhat.com,
seanjc@google.com, intel-gfx@lists.freedesktop.org,
cohuck@redhat.com, linux-kernel@vger.kernel.org,
pasic@linux.ibm.com, kvm@vger.kernel.org, pbonzini@redhat.com,
linux-s390@vger.kernel.org, borntraeger@linux.ibm.com,
intel-gvt-dev@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH v2] vfio: fix potential deadlock on vfio group lock
Date: Fri, 13 Jan 2023 10:50:29 -0400 [thread overview]
Message-ID: <Y8FvtS3uOFUnSxss@nvidia.com> (raw)
In-Reply-To: <bce7912a-f904-b5a3-d234-c3e2c42d9e54@linux.ibm.com>
On Thu, Jan 12, 2023 at 04:51:36PM -0500, Matthew Rosato wrote:
> Yep, thanks. I will surround this bit of code with
>
> mutex_lock(&device->dev_set->lock);
> ..
> mutex_unlock(&device->dev_set->lock);
Don't do it like that, copy the kvm out of the struct device to the
stack and NULL it. Then do the put without holding any locks.
Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@nvidia.com>
To: Matthew Rosato <mjrosato@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>,
pbonzini@redhat.com, cohuck@redhat.com, farman@linux.ibm.com,
pmorel@linux.ibm.com, borntraeger@linux.ibm.com,
frankja@linux.ibm.com, imbrenda@linux.ibm.com, david@redhat.com,
akrowiak@linux.ibm.com, jjherne@linux.ibm.com,
pasic@linux.ibm.com, zhenyuw@linux.intel.com,
zhi.a.wang@intel.com, seanjc@google.com,
linux-s390@vger.kernel.org, kvm@vger.kernel.org,
intel-gvt-dev@lists.freedesktop.org,
intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] vfio: fix potential deadlock on vfio group lock
Date: Fri, 13 Jan 2023 10:50:29 -0400 [thread overview]
Message-ID: <Y8FvtS3uOFUnSxss@nvidia.com> (raw)
In-Reply-To: <bce7912a-f904-b5a3-d234-c3e2c42d9e54@linux.ibm.com>
On Thu, Jan 12, 2023 at 04:51:36PM -0500, Matthew Rosato wrote:
> Yep, thanks. I will surround this bit of code with
>
> mutex_lock(&device->dev_set->lock);
> ..
> mutex_unlock(&device->dev_set->lock);
Don't do it like that, copy the kvm out of the struct device to the
stack and NULL it. Then do the put without holding any locks.
Jason
next prev parent reply other threads:[~2023-01-13 14:50 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-12 20:38 [Intel-gfx] [PATCH v2] vfio: fix potential deadlock on vfio group lock Matthew Rosato
2023-01-12 20:38 ` Matthew Rosato
2023-01-12 21:05 ` [Intel-gfx] " Alex Williamson
2023-01-12 21:05 ` Alex Williamson
2023-01-12 21:51 ` [Intel-gfx] " Matthew Rosato
2023-01-12 21:51 ` Matthew Rosato
2023-01-12 23:29 ` [Intel-gfx] " Sean Christopherson
2023-01-12 23:29 ` Sean Christopherson
2023-01-13 0:56 ` [Intel-gfx] " Alex Williamson
2023-01-13 0:56 ` Alex Williamson
2023-01-13 2:05 ` [Intel-gfx] " Sean Christopherson
2023-01-13 2:05 ` Sean Christopherson
2023-01-13 14:49 ` [Intel-gfx] " Jason Gunthorpe
2023-01-13 14:49 ` Jason Gunthorpe
2023-01-13 14:50 ` Jason Gunthorpe [this message]
2023-01-13 14:50 ` Jason Gunthorpe
2023-01-12 21:45 ` [Intel-gfx] ✓ Fi.CI.BAT: success for " Patchwork
2023-01-13 2:12 ` [Intel-gfx] [PATCH v2] " kernel test robot
2023-01-13 2:12 ` kernel test robot
2023-01-13 11:55 ` [Intel-gfx] ✓ Fi.CI.IGT: success for " Patchwork
2023-01-13 13:04 ` [Intel-gfx] [PATCH v2] " Matthew Rosato
2023-01-13 13:04 ` Matthew Rosato
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