From: Jason Gunthorpe <jgg@nvidia.com>
To: Matthew Rosato <mjrosato@linux.ibm.com>
Cc: kvm@vger.kernel.org, david@redhat.com, imbrenda@linux.ibm.com,
linux-s390@vger.kernel.org, yi.l.liu@intel.com,
frankja@linux.ibm.com, pasic@linux.ibm.com,
borntraeger@linux.ibm.com, jjherne@linux.ibm.com,
farman@linux.ibm.com, intel-gfx@lists.freedesktop.org,
intel-gvt-dev@lists.freedesktop.org, akrowiak@linux.ibm.com,
pmorel@linux.ibm.com, seanjc@google.com, cohuck@redhat.com,
linux-kernel@vger.kernel.org, pbonzini@redhat.com
Subject: Re: [Intel-gfx] [PATCH] vfio: fix deadlock between group lock and kvm lock
Date: Tue, 31 Jan 2023 16:25:30 -0400 [thread overview]
Message-ID: <Y9l5OmCRGYZM2nPy@nvidia.com> (raw)
In-Reply-To: <20230131200635.44227-1-mjrosato@linux.ibm.com>
On Tue, Jan 31, 2023 at 03:06:35PM -0500, Matthew Rosato wrote:
> @@ -799,13 +794,14 @@ EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
> void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
> {
> struct vfio_group *group = file->private_data;
> + unsigned long flags;
>
> if (!vfio_file_is_group(file))
> return;
>
> - mutex_lock(&group->group_lock);
> + spin_lock_irqsave(&group->kvm_ref_lock, flags);
> group->kvm = kvm;
> - mutex_unlock(&group->group_lock);
> + spin_unlock_irqrestore(&group->kvm_ref_lock, flags);
We know we are in a sleeping context here so these are just
'spin_lock()', same with the other one
Otherwise it seems Ok to me
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
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@redhat.com, pbonzini@redhat.com,
yi.l.liu@intel.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, kevin.tian@intel.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] vfio: fix deadlock between group lock and kvm lock
Date: Tue, 31 Jan 2023 16:25:30 -0400 [thread overview]
Message-ID: <Y9l5OmCRGYZM2nPy@nvidia.com> (raw)
In-Reply-To: <20230131200635.44227-1-mjrosato@linux.ibm.com>
On Tue, Jan 31, 2023 at 03:06:35PM -0500, Matthew Rosato wrote:
> @@ -799,13 +794,14 @@ EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
> void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
> {
> struct vfio_group *group = file->private_data;
> + unsigned long flags;
>
> if (!vfio_file_is_group(file))
> return;
>
> - mutex_lock(&group->group_lock);
> + spin_lock_irqsave(&group->kvm_ref_lock, flags);
> group->kvm = kvm;
> - mutex_unlock(&group->group_lock);
> + spin_unlock_irqrestore(&group->kvm_ref_lock, flags);
We know we are in a sleeping context here so these are just
'spin_lock()', same with the other one
Otherwise it seems Ok to me
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Jason
next prev parent reply other threads:[~2023-01-31 20:25 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-31 20:06 [Intel-gfx] [PATCH] vfio: fix deadlock between group lock and kvm lock Matthew Rosato
2023-01-31 20:06 ` Matthew Rosato
2023-01-31 20:20 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
2023-01-31 20:25 ` Jason Gunthorpe [this message]
2023-01-31 20:25 ` [PATCH] " Jason Gunthorpe
2023-02-01 12:43 ` [Intel-gfx] " Liu, Yi L
2023-02-01 12:43 ` Liu, Yi L
2023-02-01 14:42 ` [Intel-gfx] " Matthew Rosato
2023-02-01 14:42 ` Matthew Rosato
2023-02-02 3:08 ` [Intel-gfx] " Liu, Yi L
2023-02-02 3:08 ` Liu, Yi L
2023-01-31 20:47 ` [Intel-gfx] ✗ Fi.CI.BAT: failure for " Patchwork
2023-02-01 6:13 ` [Intel-gfx] [PATCH] " Tian, Kevin
2023-02-01 6:13 ` Tian, Kevin
2023-02-01 14:27 ` [Intel-gfx] " Matthew Rosato
2023-02-01 14:27 ` Matthew Rosato
2023-02-01 12:42 ` [Intel-gfx] " Liu, Yi L
2023-02-01 12:42 ` Liu, Yi L
2023-02-01 14:41 ` [Intel-gfx] " Matthew Rosato
2023-02-01 14:41 ` Matthew Rosato
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