| Message ID | 20220901143747.32858-16-kevin.tian@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Tidy up vfio_device life cycle | expand |
> From: Tian, Kevin <kevin.tian@intel.com> > Sent: Thursday, September 1, 2022 10:38 PM > > diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev > b/Documentation/ABI/testing/sysfs-devices-vfio-dev > new file mode 100644 > index 000000000000..e21424fd9666 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev > @@ -0,0 +1,8 @@ > +What: /sys/.../<device>/vfio-dev/vfioX/ > +Date: September 2022 > +Contact: Yi Liu <yi.l.liu@intel.com> > +Description: > + This directory is created when the device is bound to a > + vfio driver. The layout under this directory matches what > + exists for a standard 'struct device'. 'X' is a unique > + index marking this device in vfio. This missed an update to MAINTAINER file: diff --git a/MAINTAINERS b/MAINTAINERS index 589517372408..3fc8c599f4f2 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -21310,6 +21310,7 @@ R: Cornelia Huck <cohuck@redhat.com> L: kvm@vger.kernel.org S: Maintained T: git git://github.com/awilliam/linux-vfio.git +F: Documentation/ABI/testing/sysfs-devices-vfio-dev F: Documentation/driver-api/vfio.rst F: drivers/vfio/ F: include/linux/vfio.h Alex, I sent a wrong version w/o fixing two checkpatch warnings (this and the one in patch12). Please let me know whether you want me to resend. Thanks Kevin
Hi Kevin, On 9/1/22 16:37, Kevin Tian wrote: > From: Yi Liu <yi.l.liu@intel.com> > > and replace kref. With it a 'vfio-dev/vfioX' node is created under the > sysfs path of the parent, indicating the device is bound to a vfio > driver, e.g.: > > /sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0 > > It is also a preparatory step toward adding cdev for supporting future > device-oriented uAPI. > > Add Documentation/ABI/testing/sysfs-devices-vfio-dev. > > Also take this chance to rename chardev 'vfio' to 'vfio-group' in > /proc/devices. > > Suggested-by: Jason Gunthorpe <jgg@nvidia.com> > Signed-off-by: Yi Liu <yi.l.liu@intel.com> > Signed-off-by: Kevin Tian <kevin.tian@intel.com> > Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> > --- > .../ABI/testing/sysfs-devices-vfio-dev | 8 +++ > drivers/vfio/vfio_main.c | 67 +++++++++++++++---- > include/linux/vfio.h | 6 +- > 3 files changed, 66 insertions(+), 15 deletions(-) > create mode 100644 Documentation/ABI/testing/sysfs-devices-vfio-dev > > diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev b/Documentation/ABI/testing/sysfs-devices-vfio-dev > new file mode 100644 > index 000000000000..e21424fd9666 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev > @@ -0,0 +1,8 @@ > +What: /sys/.../<device>/vfio-dev/vfioX/ > +Date: September 2022 > +Contact: Yi Liu <yi.l.liu@intel.com> > +Description: > + This directory is created when the device is bound to a > + vfio driver. The layout under this directory matches what > + exists for a standard 'struct device'. 'X' is a unique > + index marking this device in vfio. > diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c > index bfa675d314ab..141f55c3faf5 100644 > --- a/drivers/vfio/vfio_main.c > +++ b/drivers/vfio/vfio_main.c > @@ -46,6 +46,8 @@ static struct vfio { > struct mutex group_lock; /* locks group_list */ > struct ida group_ida; > dev_t group_devt; > + struct class *device_class; > + struct ida device_ida; > } vfio; > > struct vfio_iommu_driver { > @@ -483,12 +485,13 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group, > * VFIO driver API > */ > /* Release helper called by vfio_put_device() */ > -void vfio_device_release(struct kref *kref) > +static void vfio_device_release(struct device *dev) > { > struct vfio_device *device = > - container_of(kref, struct vfio_device, kref); > + container_of(dev, struct vfio_device, device); > > vfio_release_device_set(device); > + ida_free(&vfio.device_ida, device->index); > > /* > * kvfree() cannot be done here due to a life cycle mess in > @@ -498,7 +501,6 @@ void vfio_device_release(struct kref *kref) > */ > device->ops->release(device); > } > -EXPORT_SYMBOL_GPL(vfio_device_release); > > /* > * Alloc and initialize vfio_device so it can be registered to vfio > @@ -546,6 +548,13 @@ int vfio_init_device(struct vfio_device *device, struct device *dev, > { > int ret; > > + ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL); > + if (ret < 0) { > + dev_dbg(dev, "Error to alloc index\n"); > + return ret; > + } > + > + device->index = ret; > init_completion(&device->comp); > device->dev = dev; > device->ops = ops; > @@ -556,11 +565,15 @@ int vfio_init_device(struct vfio_device *device, struct device *dev, > goto out_uninit; > } > > - kref_init(&device->kref); > + device_initialize(&device->device); > + device->device.release = vfio_device_release; > + device->device.class = vfio.device_class; > + device->device.parent = device->dev; > return 0; > > out_uninit: > vfio_release_device_set(device); > + ida_free(&vfio.device_ida, device->index); > return ret; > } > EXPORT_SYMBOL_GPL(vfio_init_device); > @@ -657,6 +670,7 @@ static int __vfio_register_dev(struct vfio_device *device, > struct vfio_group *group) > { > struct vfio_device *existing_device; > + int ret; > > if (IS_ERR(group)) > return PTR_ERR(group); > @@ -673,16 +687,21 @@ static int __vfio_register_dev(struct vfio_device *device, > dev_WARN(device->dev, "Device already exists on group %d\n", > iommu_group_id(group->iommu_group)); > vfio_device_put_registration(existing_device); > - if (group->type == VFIO_NO_IOMMU || > - group->type == VFIO_EMULATED_IOMMU) > - iommu_group_remove_device(device->dev); > - vfio_group_put(group); > - return -EBUSY; > + ret = -EBUSY; > + goto err_out; > } > > /* Our reference on group is moved to the device */ > device->group = group; > > + ret = dev_set_name(&device->device, "vfio%d", device->index); > + if (ret) > + goto err_out; > + > + ret = device_add(&device->device); > + if (ret) > + goto err_out; > + > /* Refcounting can't start until the driver calls register */ > refcount_set(&device->refcount, 1); > > @@ -692,6 +711,12 @@ static int __vfio_register_dev(struct vfio_device *device, > mutex_unlock(&group->device_lock); > > return 0; > +err_out: > + if (group->type == VFIO_NO_IOMMU || > + group->type == VFIO_EMULATED_IOMMU) > + iommu_group_remove_device(device->dev); > + vfio_group_put(group); > + return ret; > } > > int vfio_register_group_dev(struct vfio_device *device) > @@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct vfio_device *device) > group->dev_counter--; > mutex_unlock(&group->device_lock); > > + /* Balances device_add in register path */ > + device_del(&device->device); > + > if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) > iommu_group_remove_device(device->dev); > > @@ -2145,6 +2173,7 @@ static int __init vfio_init(void) > int ret; > > ida_init(&vfio.group_ida); > + ida_init(&vfio.device_ida); > mutex_init(&vfio.group_lock); > mutex_init(&vfio.iommu_drivers_lock); > INIT_LIST_HEAD(&vfio.group_list); > @@ -2160,12 +2189,20 @@ static int __init vfio_init(void) > vfio.class = class_create(THIS_MODULE, "vfio"); > if (IS_ERR(vfio.class)) { > ret = PTR_ERR(vfio.class); > - goto err_class; > + goto err_group_class; > } > > vfio.class->devnode = vfio_devnode; > > - ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); > + /* /sys/class/vfio-dev/vfioX */ > + vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); > + if (IS_ERR(vfio.device_class)) { > + ret = PTR_ERR(vfio.device_class); > + goto err_dev_class; > + } > + > + ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, > + "vfio-group"); > if (ret) > goto err_alloc_chrdev; > > @@ -2181,9 +2218,12 @@ static int __init vfio_init(void) > err_driver_register: > unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); > err_alloc_chrdev: > + class_destroy(vfio.device_class); > + vfio.device_class = NULL; > +err_dev_class: > class_destroy(vfio.class); > vfio.class = NULL; > -err_class: > +err_group_class: > misc_deregister(&vfio_dev); > return ret; > } > @@ -2195,8 +2235,11 @@ static void __exit vfio_cleanup(void) > #ifdef CONFIG_VFIO_NOIOMMU > vfio_unregister_iommu_driver(&vfio_noiommu_ops); > #endif > + ida_destroy(&vfio.device_ida); > ida_destroy(&vfio.group_ida); > unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); > + class_destroy(vfio.device_class); > + vfio.device_class = NULL; > class_destroy(vfio.class); > vfio.class = NULL; > misc_deregister(&vfio_dev); > diff --git a/include/linux/vfio.h b/include/linux/vfio.h > index f03447c8774d..5c13f74da1bb 100644 > --- a/include/linux/vfio.h > +++ b/include/linux/vfio.h > @@ -45,7 +45,8 @@ struct vfio_device { > struct kvm *kvm; > > /* Members below here are private, not for driver use */ > - struct kref kref; /* object life cycle */ > + unsigned int index; > + struct device device; /* device.kref covers object life circle */ > refcount_t refcount; /* user count on registered device*/ > unsigned int open_count; > struct completion comp; I am not totally clear about remaining 'struct device *dev;' in vfio_device struct. I see it used in some places. Is it supposed to disappear at some point? > @@ -154,10 +155,9 @@ struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev, > int vfio_init_device(struct vfio_device *device, struct device *dev, > const struct vfio_device_ops *ops); > void vfio_free_device(struct vfio_device *device); > -void vfio_device_release(struct kref *kref); > static inline void vfio_put_device(struct vfio_device *device) > { > - kref_put(&device->kref, vfio_device_release); > + put_device(&device->device); > } > > int vfio_register_group_dev(struct vfio_device *device); Thanks Eric
On 2022/9/8 17:06, Eric Auger wrote: > Hi Kevin, > > On 9/1/22 16:37, Kevin Tian wrote: >> From: Yi Liu <yi.l.liu@intel.com> >> >> and replace kref. With it a 'vfio-dev/vfioX' node is created under the >> sysfs path of the parent, indicating the device is bound to a vfio >> driver, e.g.: >> >> /sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0 >> >> It is also a preparatory step toward adding cdev for supporting future >> device-oriented uAPI. >> >> Add Documentation/ABI/testing/sysfs-devices-vfio-dev. >> >> Also take this chance to rename chardev 'vfio' to 'vfio-group' in >> /proc/devices. >> >> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> >> Signed-off-by: Yi Liu <yi.l.liu@intel.com> >> Signed-off-by: Kevin Tian <kevin.tian@intel.com> >> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> >> --- >> .../ABI/testing/sysfs-devices-vfio-dev | 8 +++ >> drivers/vfio/vfio_main.c | 67 +++++++++++++++---- >> include/linux/vfio.h | 6 +- >> 3 files changed, 66 insertions(+), 15 deletions(-) >> create mode 100644 Documentation/ABI/testing/sysfs-devices-vfio-dev >> >> diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev b/Documentation/ABI/testing/sysfs-devices-vfio-dev >> new file mode 100644 >> index 000000000000..e21424fd9666 >> --- /dev/null >> +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev >> @@ -0,0 +1,8 @@ >> +What: /sys/.../<device>/vfio-dev/vfioX/ >> +Date: September 2022 >> +Contact: Yi Liu <yi.l.liu@intel.com> >> +Description: >> + This directory is created when the device is bound to a >> + vfio driver. The layout under this directory matches what >> + exists for a standard 'struct device'. 'X' is a unique >> + index marking this device in vfio. >> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c >> index bfa675d314ab..141f55c3faf5 100644 >> --- a/drivers/vfio/vfio_main.c >> +++ b/drivers/vfio/vfio_main.c >> @@ -46,6 +46,8 @@ static struct vfio { >> struct mutex group_lock; /* locks group_list */ >> struct ida group_ida; >> dev_t group_devt; >> + struct class *device_class; >> + struct ida device_ida; >> } vfio; >> >> struct vfio_iommu_driver { >> @@ -483,12 +485,13 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group, >> * VFIO driver API >> */ >> /* Release helper called by vfio_put_device() */ >> -void vfio_device_release(struct kref *kref) >> +static void vfio_device_release(struct device *dev) >> { >> struct vfio_device *device = >> - container_of(kref, struct vfio_device, kref); >> + container_of(dev, struct vfio_device, device); >> >> vfio_release_device_set(device); >> + ida_free(&vfio.device_ida, device->index); >> >> /* >> * kvfree() cannot be done here due to a life cycle mess in >> @@ -498,7 +501,6 @@ void vfio_device_release(struct kref *kref) >> */ >> device->ops->release(device); >> } >> -EXPORT_SYMBOL_GPL(vfio_device_release); >> >> /* >> * Alloc and initialize vfio_device so it can be registered to vfio >> @@ -546,6 +548,13 @@ int vfio_init_device(struct vfio_device *device, struct device *dev, >> { >> int ret; >> >> + ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL); >> + if (ret < 0) { >> + dev_dbg(dev, "Error to alloc index\n"); >> + return ret; >> + } >> + >> + device->index = ret; >> init_completion(&device->comp); >> device->dev = dev; >> device->ops = ops; >> @@ -556,11 +565,15 @@ int vfio_init_device(struct vfio_device *device, struct device *dev, >> goto out_uninit; >> } >> >> - kref_init(&device->kref); >> + device_initialize(&device->device); >> + device->device.release = vfio_device_release; >> + device->device.class = vfio.device_class; >> + device->device.parent = device->dev; >> return 0; >> >> out_uninit: >> vfio_release_device_set(device); >> + ida_free(&vfio.device_ida, device->index); >> return ret; >> } >> EXPORT_SYMBOL_GPL(vfio_init_device); >> @@ -657,6 +670,7 @@ static int __vfio_register_dev(struct vfio_device *device, >> struct vfio_group *group) >> { >> struct vfio_device *existing_device; >> + int ret; >> >> if (IS_ERR(group)) >> return PTR_ERR(group); >> @@ -673,16 +687,21 @@ static int __vfio_register_dev(struct vfio_device *device, >> dev_WARN(device->dev, "Device already exists on group %d\n", >> iommu_group_id(group->iommu_group)); >> vfio_device_put_registration(existing_device); >> - if (group->type == VFIO_NO_IOMMU || >> - group->type == VFIO_EMULATED_IOMMU) >> - iommu_group_remove_device(device->dev); >> - vfio_group_put(group); >> - return -EBUSY; >> + ret = -EBUSY; >> + goto err_out; >> } >> >> /* Our reference on group is moved to the device */ >> device->group = group; >> >> + ret = dev_set_name(&device->device, "vfio%d", device->index); >> + if (ret) >> + goto err_out; >> + >> + ret = device_add(&device->device); >> + if (ret) >> + goto err_out; >> + >> /* Refcounting can't start until the driver calls register */ >> refcount_set(&device->refcount, 1); >> >> @@ -692,6 +711,12 @@ static int __vfio_register_dev(struct vfio_device *device, >> mutex_unlock(&group->device_lock); >> >> return 0; >> +err_out: >> + if (group->type == VFIO_NO_IOMMU || >> + group->type == VFIO_EMULATED_IOMMU) >> + iommu_group_remove_device(device->dev); >> + vfio_group_put(group); >> + return ret; >> } >> >> int vfio_register_group_dev(struct vfio_device *device) >> @@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct vfio_device *device) >> group->dev_counter--; >> mutex_unlock(&group->device_lock); >> >> + /* Balances device_add in register path */ >> + device_del(&device->device); >> + >> if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) >> iommu_group_remove_device(device->dev); >> >> @@ -2145,6 +2173,7 @@ static int __init vfio_init(void) >> int ret; >> >> ida_init(&vfio.group_ida); >> + ida_init(&vfio.device_ida); >> mutex_init(&vfio.group_lock); >> mutex_init(&vfio.iommu_drivers_lock); >> INIT_LIST_HEAD(&vfio.group_list); >> @@ -2160,12 +2189,20 @@ static int __init vfio_init(void) >> vfio.class = class_create(THIS_MODULE, "vfio"); >> if (IS_ERR(vfio.class)) { >> ret = PTR_ERR(vfio.class); >> - goto err_class; >> + goto err_group_class; >> } >> >> vfio.class->devnode = vfio_devnode; >> >> - ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); >> + /* /sys/class/vfio-dev/vfioX */ >> + vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); >> + if (IS_ERR(vfio.device_class)) { >> + ret = PTR_ERR(vfio.device_class); >> + goto err_dev_class; >> + } >> + >> + ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, >> + "vfio-group"); >> if (ret) >> goto err_alloc_chrdev; >> >> @@ -2181,9 +2218,12 @@ static int __init vfio_init(void) >> err_driver_register: >> unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); >> err_alloc_chrdev: >> + class_destroy(vfio.device_class); >> + vfio.device_class = NULL; >> +err_dev_class: >> class_destroy(vfio.class); >> vfio.class = NULL; >> -err_class: >> +err_group_class: >> misc_deregister(&vfio_dev); >> return ret; >> } >> @@ -2195,8 +2235,11 @@ static void __exit vfio_cleanup(void) >> #ifdef CONFIG_VFIO_NOIOMMU >> vfio_unregister_iommu_driver(&vfio_noiommu_ops); >> #endif >> + ida_destroy(&vfio.device_ida); >> ida_destroy(&vfio.group_ida); >> unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); >> + class_destroy(vfio.device_class); >> + vfio.device_class = NULL; >> class_destroy(vfio.class); >> vfio.class = NULL; >> misc_deregister(&vfio_dev); >> diff --git a/include/linux/vfio.h b/include/linux/vfio.h >> index f03447c8774d..5c13f74da1bb 100644 >> --- a/include/linux/vfio.h >> +++ b/include/linux/vfio.h >> @@ -45,7 +45,8 @@ struct vfio_device { >> struct kvm *kvm; >> >> /* Members below here are private, not for driver use */ >> - struct kref kref; /* object life cycle */ >> + unsigned int index; >> + struct device device; /* device.kref covers object life circle */ >> refcount_t refcount; /* user count on registered device*/ >> unsigned int open_count; >> struct completion comp; > I am not totally clear about remaining 'struct device *dev;' in > vfio_device struct. I see it used in some places. Is it supposed to > disappear at some point? no, Eric. *dev will not disappear, it stores the dev pointet passed in by caller of vfio_init_device(). >> @@ -154,10 +155,9 @@ struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev, >> int vfio_init_device(struct vfio_device *device, struct device *dev, >> const struct vfio_device_ops *ops); >> void vfio_free_device(struct vfio_device *device); >> -void vfio_device_release(struct kref *kref); >> static inline void vfio_put_device(struct vfio_device *device) >> { >> - kref_put(&device->kref, vfio_device_release); >> + put_device(&device->device); >> } >> >> int vfio_register_group_dev(struct vfio_device *device); > > Thanks > > Eric >
On 9/8/22 11:17, Yi Liu wrote: > On 2022/9/8 17:06, Eric Auger wrote: >> Hi Kevin, >> >> On 9/1/22 16:37, Kevin Tian wrote: >>> From: Yi Liu <yi.l.liu@intel.com> >>> >>> and replace kref. With it a 'vfio-dev/vfioX' node is created under the >>> sysfs path of the parent, indicating the device is bound to a vfio >>> driver, e.g.: >>> >>> /sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0 >>> >>> It is also a preparatory step toward adding cdev for supporting future >>> device-oriented uAPI. >>> >>> Add Documentation/ABI/testing/sysfs-devices-vfio-dev. >>> >>> Also take this chance to rename chardev 'vfio' to 'vfio-group' in >>> /proc/devices. >>> >>> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> >>> Signed-off-by: Yi Liu <yi.l.liu@intel.com> >>> Signed-off-by: Kevin Tian <kevin.tian@intel.com> >>> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> >>> --- >>> .../ABI/testing/sysfs-devices-vfio-dev | 8 +++ >>> drivers/vfio/vfio_main.c | 67 >>> +++++++++++++++---- >>> include/linux/vfio.h | 6 +- >>> 3 files changed, 66 insertions(+), 15 deletions(-) >>> create mode 100644 Documentation/ABI/testing/sysfs-devices-vfio-dev >>> >>> diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev >>> b/Documentation/ABI/testing/sysfs-devices-vfio-dev >>> new file mode 100644 >>> index 000000000000..e21424fd9666 >>> --- /dev/null >>> +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev >>> @@ -0,0 +1,8 @@ >>> +What: /sys/.../<device>/vfio-dev/vfioX/ >>> +Date: September 2022 >>> +Contact: Yi Liu <yi.l.liu@intel.com> >>> +Description: >>> + This directory is created when the device is bound to a >>> + vfio driver. The layout under this directory matches what >>> + exists for a standard 'struct device'. 'X' is a unique >>> + index marking this device in vfio. >>> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c >>> index bfa675d314ab..141f55c3faf5 100644 >>> --- a/drivers/vfio/vfio_main.c >>> +++ b/drivers/vfio/vfio_main.c >>> @@ -46,6 +46,8 @@ static struct vfio { >>> struct mutex group_lock; /* locks group_list */ >>> struct ida group_ida; >>> dev_t group_devt; >>> + struct class *device_class; >>> + struct ida device_ida; >>> } vfio; >>> struct vfio_iommu_driver { >>> @@ -483,12 +485,13 @@ static struct vfio_device >>> *vfio_group_get_device(struct vfio_group *group, >>> * VFIO driver API >>> */ >>> /* Release helper called by vfio_put_device() */ >>> -void vfio_device_release(struct kref *kref) >>> +static void vfio_device_release(struct device *dev) >>> { >>> struct vfio_device *device = >>> - container_of(kref, struct vfio_device, kref); >>> + container_of(dev, struct vfio_device, device); >>> vfio_release_device_set(device); >>> + ida_free(&vfio.device_ida, device->index); >>> /* >>> * kvfree() cannot be done here due to a life cycle mess in >>> @@ -498,7 +501,6 @@ void vfio_device_release(struct kref *kref) >>> */ >>> device->ops->release(device); >>> } >>> -EXPORT_SYMBOL_GPL(vfio_device_release); >>> /* >>> * Alloc and initialize vfio_device so it can be registered to vfio >>> @@ -546,6 +548,13 @@ int vfio_init_device(struct vfio_device >>> *device, struct device *dev, >>> { >>> int ret; >>> + ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL); >>> + if (ret < 0) { >>> + dev_dbg(dev, "Error to alloc index\n"); >>> + return ret; >>> + } >>> + >>> + device->index = ret; >>> init_completion(&device->comp); >>> device->dev = dev; >>> device->ops = ops; >>> @@ -556,11 +565,15 @@ int vfio_init_device(struct vfio_device >>> *device, struct device *dev, >>> goto out_uninit; >>> } >>> - kref_init(&device->kref); >>> + device_initialize(&device->device); >>> + device->device.release = vfio_device_release; >>> + device->device.class = vfio.device_class; >>> + device->device.parent = device->dev; >>> return 0; >>> out_uninit: >>> vfio_release_device_set(device); >>> + ida_free(&vfio.device_ida, device->index); >>> return ret; >>> } >>> EXPORT_SYMBOL_GPL(vfio_init_device); >>> @@ -657,6 +670,7 @@ static int __vfio_register_dev(struct >>> vfio_device *device, >>> struct vfio_group *group) >>> { >>> struct vfio_device *existing_device; >>> + int ret; >>> if (IS_ERR(group)) >>> return PTR_ERR(group); >>> @@ -673,16 +687,21 @@ static int __vfio_register_dev(struct >>> vfio_device *device, >>> dev_WARN(device->dev, "Device already exists on group %d\n", >>> iommu_group_id(group->iommu_group)); >>> vfio_device_put_registration(existing_device); >>> - if (group->type == VFIO_NO_IOMMU || >>> - group->type == VFIO_EMULATED_IOMMU) >>> - iommu_group_remove_device(device->dev); >>> - vfio_group_put(group); >>> - return -EBUSY; >>> + ret = -EBUSY; >>> + goto err_out; >>> } >>> /* Our reference on group is moved to the device */ >>> device->group = group; >>> + ret = dev_set_name(&device->device, "vfio%d", device->index); >>> + if (ret) >>> + goto err_out; >>> + >>> + ret = device_add(&device->device); >>> + if (ret) >>> + goto err_out; >>> + >>> /* Refcounting can't start until the driver calls register */ >>> refcount_set(&device->refcount, 1); >>> @@ -692,6 +711,12 @@ static int __vfio_register_dev(struct >>> vfio_device *device, >>> mutex_unlock(&group->device_lock); >>> return 0; >>> +err_out: >>> + if (group->type == VFIO_NO_IOMMU || >>> + group->type == VFIO_EMULATED_IOMMU) >>> + iommu_group_remove_device(device->dev); >>> + vfio_group_put(group); >>> + return ret; >>> } >>> int vfio_register_group_dev(struct vfio_device *device) >>> @@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct >>> vfio_device *device) >>> group->dev_counter--; >>> mutex_unlock(&group->device_lock); >>> + /* Balances device_add in register path */ >>> + device_del(&device->device); >>> + >>> if (group->type == VFIO_NO_IOMMU || group->type == >>> VFIO_EMULATED_IOMMU) >>> iommu_group_remove_device(device->dev); >>> @@ -2145,6 +2173,7 @@ static int __init vfio_init(void) >>> int ret; >>> ida_init(&vfio.group_ida); >>> + ida_init(&vfio.device_ida); >>> mutex_init(&vfio.group_lock); >>> mutex_init(&vfio.iommu_drivers_lock); >>> INIT_LIST_HEAD(&vfio.group_list); >>> @@ -2160,12 +2189,20 @@ static int __init vfio_init(void) >>> vfio.class = class_create(THIS_MODULE, "vfio"); >>> if (IS_ERR(vfio.class)) { >>> ret = PTR_ERR(vfio.class); >>> - goto err_class; >>> + goto err_group_class; >>> } >>> vfio.class->devnode = vfio_devnode; >>> - ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, >>> "vfio"); >>> + /* /sys/class/vfio-dev/vfioX */ >>> + vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); >>> + if (IS_ERR(vfio.device_class)) { >>> + ret = PTR_ERR(vfio.device_class); >>> + goto err_dev_class; >>> + } >>> + >>> + ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, >>> + "vfio-group"); >>> if (ret) >>> goto err_alloc_chrdev; >>> @@ -2181,9 +2218,12 @@ static int __init vfio_init(void) >>> err_driver_register: >>> unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); >>> err_alloc_chrdev: >>> + class_destroy(vfio.device_class); >>> + vfio.device_class = NULL; >>> +err_dev_class: >>> class_destroy(vfio.class); >>> vfio.class = NULL; >>> -err_class: >>> +err_group_class: >>> misc_deregister(&vfio_dev); >>> return ret; >>> } >>> @@ -2195,8 +2235,11 @@ static void __exit vfio_cleanup(void) >>> #ifdef CONFIG_VFIO_NOIOMMU >>> vfio_unregister_iommu_driver(&vfio_noiommu_ops); >>> #endif >>> + ida_destroy(&vfio.device_ida); >>> ida_destroy(&vfio.group_ida); >>> unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); >>> + class_destroy(vfio.device_class); >>> + vfio.device_class = NULL; >>> class_destroy(vfio.class); >>> vfio.class = NULL; >>> misc_deregister(&vfio_dev); >>> diff --git a/include/linux/vfio.h b/include/linux/vfio.h >>> index f03447c8774d..5c13f74da1bb 100644 >>> --- a/include/linux/vfio.h >>> +++ b/include/linux/vfio.h >>> @@ -45,7 +45,8 @@ struct vfio_device { >>> struct kvm *kvm; >>> /* Members below here are private, not for driver use */ >>> - struct kref kref; /* object life cycle */ >>> + unsigned int index; >>> + struct device device; /* device.kref covers object life >>> circle */ >>> refcount_t refcount; /* user count on registered device*/ >>> unsigned int open_count; >>> struct completion comp; >> I am not totally clear about remaining 'struct device *dev;' in >> vfio_device struct. I see it used in some places. Is it supposed to >> disappear at some point? > > no, Eric. *dev will not disappear, it stores the dev pointet passed in by > caller of vfio_init_device(). yeah I see but you have device->device.parent = device->dev; Eric > >>> @@ -154,10 +155,9 @@ struct vfio_device *_vfio_alloc_device(size_t >>> size, struct device *dev, >>> int vfio_init_device(struct vfio_device *device, struct device *dev, >>> const struct vfio_device_ops *ops); >>> void vfio_free_device(struct vfio_device *device); >>> -void vfio_device_release(struct kref *kref); >>> static inline void vfio_put_device(struct vfio_device *device) >>> { >>> - kref_put(&device->kref, vfio_device_release); >>> + put_device(&device->device); >>> } >>> int vfio_register_group_dev(struct vfio_device *device); >> >> Thanks >> >> Eric >> >
On Thu, Sep 08, 2022 at 11:39:07AM +0200, Eric Auger wrote: > >> I am not totally clear about remaining 'struct device *dev;' in > >> vfio_device struct. I see it used in some places. Is it supposed to > >> disappear at some point? > > > > no, Eric. *dev will not disappear, it stores the dev pointet passed in by > > caller of vfio_init_device(). > > yeah I see but you have device->device.parent = device->dev; IIRC we have a number of these redundancies now, often the drivers store another copy of the dev too. A significant use of dev is for printing things, what should be done here is to create a subsystem wide vfio_warn/etc that takes in the vfio_device, and then print properly from there. Now that we have a struct device all the prints should also include the VFIO struct device name, and then the PCI device perhaps in brackets. Jason
> From: Jason Gunthorpe > Sent: Thursday, September 8, 2022 8:37 PM > > On Thu, Sep 08, 2022 at 11:39:07AM +0200, Eric Auger wrote: > > > >> I am not totally clear about remaining 'struct device *dev;' in > > >> vfio_device struct. I see it used in some places. Is it supposed to > > >> disappear at some point? > > > > > > no, Eric. *dev will not disappear, it stores the dev pointet passed in by > > > caller of vfio_init_device(). > > > > yeah I see but you have device->device.parent = device->dev; > > IIRC we have a number of these redundancies now, often the drivers > store another copy of the dev too. > > A significant use of dev is for printing things, what should be done > here is to create a subsystem wide vfio_warn/etc that takes in the > vfio_device, and then print properly from there. Now that we have a > struct device all the prints should also include the VFIO struct > device name, and then the PCI device perhaps in brackets. > Let me handle it in a separate patch (after this series).
diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev b/Documentation/ABI/testing/sysfs-devices-vfio-dev new file mode 100644 index 000000000000..e21424fd9666 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev @@ -0,0 +1,8 @@ +What: /sys/.../<device>/vfio-dev/vfioX/ +Date: September 2022 +Contact: Yi Liu <yi.l.liu@intel.com> +Description: + This directory is created when the device is bound to a + vfio driver. The layout under this directory matches what + exists for a standard 'struct device'. 'X' is a unique + index marking this device in vfio. diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index bfa675d314ab..141f55c3faf5 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -46,6 +46,8 @@ static struct vfio { struct mutex group_lock; /* locks group_list */ struct ida group_ida; dev_t group_devt; + struct class *device_class; + struct ida device_ida; } vfio; struct vfio_iommu_driver { @@ -483,12 +485,13 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group, * VFIO driver API */ /* Release helper called by vfio_put_device() */ -void vfio_device_release(struct kref *kref) +static void vfio_device_release(struct device *dev) { struct vfio_device *device = - container_of(kref, struct vfio_device, kref); + container_of(dev, struct vfio_device, device); vfio_release_device_set(device); + ida_free(&vfio.device_ida, device->index); /* * kvfree() cannot be done here due to a life cycle mess in @@ -498,7 +501,6 @@ void vfio_device_release(struct kref *kref) */ device->ops->release(device); } -EXPORT_SYMBOL_GPL(vfio_device_release); /* * Alloc and initialize vfio_device so it can be registered to vfio @@ -546,6 +548,13 @@ int vfio_init_device(struct vfio_device *device, struct device *dev, { int ret; + ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL); + if (ret < 0) { + dev_dbg(dev, "Error to alloc index\n"); + return ret; + } + + device->index = ret; init_completion(&device->comp); device->dev = dev; device->ops = ops; @@ -556,11 +565,15 @@ int vfio_init_device(struct vfio_device *device, struct device *dev, goto out_uninit; } - kref_init(&device->kref); + device_initialize(&device->device); + device->device.release = vfio_device_release; + device->device.class = vfio.device_class; + device->device.parent = device->dev; return 0; out_uninit: vfio_release_device_set(device); + ida_free(&vfio.device_ida, device->index); return ret; } EXPORT_SYMBOL_GPL(vfio_init_device); @@ -657,6 +670,7 @@ static int __vfio_register_dev(struct vfio_device *device, struct vfio_group *group) { struct vfio_device *existing_device; + int ret; if (IS_ERR(group)) return PTR_ERR(group); @@ -673,16 +687,21 @@ static int __vfio_register_dev(struct vfio_device *device, dev_WARN(device->dev, "Device already exists on group %d\n", iommu_group_id(group->iommu_group)); vfio_device_put_registration(existing_device); - if (group->type == VFIO_NO_IOMMU || - group->type == VFIO_EMULATED_IOMMU) - iommu_group_remove_device(device->dev); - vfio_group_put(group); - return -EBUSY; + ret = -EBUSY; + goto err_out; } /* Our reference on group is moved to the device */ device->group = group; + ret = dev_set_name(&device->device, "vfio%d", device->index); + if (ret) + goto err_out; + + ret = device_add(&device->device); + if (ret) + goto err_out; + /* Refcounting can't start until the driver calls register */ refcount_set(&device->refcount, 1); @@ -692,6 +711,12 @@ static int __vfio_register_dev(struct vfio_device *device, mutex_unlock(&group->device_lock); return 0; +err_out: + if (group->type == VFIO_NO_IOMMU || + group->type == VFIO_EMULATED_IOMMU) + iommu_group_remove_device(device->dev); + vfio_group_put(group); + return ret; } int vfio_register_group_dev(struct vfio_device *device) @@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct vfio_device *device) group->dev_counter--; mutex_unlock(&group->device_lock); + /* Balances device_add in register path */ + device_del(&device->device); + if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) iommu_group_remove_device(device->dev); @@ -2145,6 +2173,7 @@ static int __init vfio_init(void) int ret; ida_init(&vfio.group_ida); + ida_init(&vfio.device_ida); mutex_init(&vfio.group_lock); mutex_init(&vfio.iommu_drivers_lock); INIT_LIST_HEAD(&vfio.group_list); @@ -2160,12 +2189,20 @@ static int __init vfio_init(void) vfio.class = class_create(THIS_MODULE, "vfio"); if (IS_ERR(vfio.class)) { ret = PTR_ERR(vfio.class); - goto err_class; + goto err_group_class; } vfio.class->devnode = vfio_devnode; - ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); + /* /sys/class/vfio-dev/vfioX */ + vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); + if (IS_ERR(vfio.device_class)) { + ret = PTR_ERR(vfio.device_class); + goto err_dev_class; + } + + ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, + "vfio-group"); if (ret) goto err_alloc_chrdev; @@ -2181,9 +2218,12 @@ static int __init vfio_init(void) err_driver_register: unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); err_alloc_chrdev: + class_destroy(vfio.device_class); + vfio.device_class = NULL; +err_dev_class: class_destroy(vfio.class); vfio.class = NULL; -err_class: +err_group_class: misc_deregister(&vfio_dev); return ret; } @@ -2195,8 +2235,11 @@ static void __exit vfio_cleanup(void) #ifdef CONFIG_VFIO_NOIOMMU vfio_unregister_iommu_driver(&vfio_noiommu_ops); #endif + ida_destroy(&vfio.device_ida); ida_destroy(&vfio.group_ida); unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); + class_destroy(vfio.device_class); + vfio.device_class = NULL; class_destroy(vfio.class); vfio.class = NULL; misc_deregister(&vfio_dev); diff --git a/include/linux/vfio.h b/include/linux/vfio.h index f03447c8774d..5c13f74da1bb 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -45,7 +45,8 @@ struct vfio_device { struct kvm *kvm; /* Members below here are private, not for driver use */ - struct kref kref; /* object life cycle */ + unsigned int index; + struct device device; /* device.kref covers object life circle */ refcount_t refcount; /* user count on registered device*/ unsigned int open_count; struct completion comp; @@ -154,10 +155,9 @@ struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev, int vfio_init_device(struct vfio_device *device, struct device *dev, const struct vfio_device_ops *ops); void vfio_free_device(struct vfio_device *device); -void vfio_device_release(struct kref *kref); static inline void vfio_put_device(struct vfio_device *device) { - kref_put(&device->kref, vfio_device_release); + put_device(&device->device); } int vfio_register_group_dev(struct vfio_device *device);