From:   "Tian, Kevin" <kevin.tian@intel.com>
To:     Alex Williamson <alex.williamson@redhat.com>,
        Matthew Rosato <mjrosato@linux.ibm.com>
CC:     "pbonzini@redhat.com" <pbonzini@redhat.com>,
        "Liu, Yi L" <yi.l.liu@intel.com>,
        "jgg@nvidia.com" <jgg@nvidia.com>,
        "cohuck@redhat.com" <cohuck@redhat.com>,
        "farman@linux.ibm.com" <farman@linux.ibm.com>,
        "pmorel@linux.ibm.com" <pmorel@linux.ibm.com>,
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        "frankja@linux.ibm.com" <frankja@linux.ibm.com>,
        "imbrenda@linux.ibm.com" <imbrenda@linux.ibm.com>,
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        "akrowiak@linux.ibm.com" <akrowiak@linux.ibm.com>,
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        "pasic@linux.ibm.com" <pasic@linux.ibm.com>,
        "zhenyuw@linux.intel.com" <zhenyuw@linux.intel.com>,
        "Wang, Zhi A" <zhi.a.wang@intel.com>,
        "Christopherson,, Sean" <seanjc@google.com>,
        "linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "intel-gvt-dev@lists.freedesktop.org" 
        <intel-gvt-dev@lists.freedesktop.org>,
        "intel-gfx@lists.freedesktop.org" <intel-gfx@lists.freedesktop.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2] vfio: fix deadlock between group lock and kvm lock
Thread-Topic: [PATCH v2] vfio: fix deadlock between group lock and kvm lock
Thread-Index: AQHZNnJFiVrNVn+VRUK8FiGvi+QS2a66vJwAgABONbA=
Date:   Thu, 2 Feb 2023 04:10:20 +0000
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References: <20230201192010.42748-1-mjrosato@linux.ibm.com>
 <20230201162730.685b5332.alex.williamson@redhat.com>
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> From: Alex Williamson <alex.williamson@redhat.com>
> Sent: Thursday, February 2, 2023 7:28 AM
> >
> > +#ifdef CONFIG_HAVE_KVM
> > +static bool vfio_kvm_get_kvm_safe(struct vfio_device *device, struct k=
vm
> *kvm)
>=20
> I'm tempted to name these vfio_device_get_kvm_safe() and only pass the
> vfio_device, where of course we can get the kvm pointer from the group
> internally.
>=20

I have a different thought. In the end the cdev series also need the simila=
r
safe get/put logic then it's better to keep it in vfio_main.c called by
the group/cdev path individually.