diff options
Diffstat (limited to 'drivers/vfio/group.c')
| -rw-r--r-- | drivers/vfio/group.c | 173 |
1 files changed, 111 insertions, 62 deletions
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c index fc75c1000d74..610a429c6191 100644 --- a/drivers/vfio/group.c +++ b/drivers/vfio/group.c @@ -160,17 +160,13 @@ out_unlock: static void vfio_device_group_get_kvm_safe(struct vfio_device *device) { spin_lock(&device->group->kvm_ref_lock); - if (!device->group->kvm) - goto unlock; - - _vfio_device_get_kvm_safe(device, device->group->kvm); - -unlock: + vfio_device_get_kvm_safe(device, device->group->kvm); spin_unlock(&device->group->kvm_ref_lock); } -static int vfio_device_group_open(struct vfio_device *device) +static int vfio_df_group_open(struct vfio_device_file *df) { + struct vfio_device *device = df->device; int ret; mutex_lock(&device->group->group_lock); @@ -190,24 +186,62 @@ static int vfio_device_group_open(struct vfio_device *device) if (device->open_count == 0) vfio_device_group_get_kvm_safe(device); - ret = vfio_device_open(device, device->group->iommufd); + df->iommufd = device->group->iommufd; + if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count == 0) { + /* + * Require no compat ioas to be assigned to proceed. The basic + * statement is that the user cannot have done something that + * implies they expected translation to exist + */ + if (!capable(CAP_SYS_RAWIO) || + vfio_iommufd_device_has_compat_ioas(device, df->iommufd)) + ret = -EPERM; + else + ret = 0; + goto out_put_kvm; + } - if (device->open_count == 0) - vfio_device_put_kvm(device); + ret = vfio_df_open(df); + if (ret) + goto out_put_kvm; + + if (df->iommufd && device->open_count == 1) { + ret = vfio_iommufd_compat_attach_ioas(device, df->iommufd); + if (ret) + goto out_close_device; + } + + /* + * Paired with smp_load_acquire() in vfio_device_fops::ioctl/ + * read/write/mmap and vfio_file_has_device_access() + */ + smp_store_release(&df->access_granted, true); mutex_unlock(&device->dev_set->lock); + mutex_unlock(&device->group->group_lock); + return 0; +out_close_device: + vfio_df_close(df); +out_put_kvm: + df->iommufd = NULL; + if (device->open_count == 0) + vfio_device_put_kvm(device); + mutex_unlock(&device->dev_set->lock); out_unlock: mutex_unlock(&device->group->group_lock); return ret; } -void vfio_device_group_close(struct vfio_device *device) +void vfio_df_group_close(struct vfio_device_file *df) { + struct vfio_device *device = df->device; + mutex_lock(&device->group->group_lock); mutex_lock(&device->dev_set->lock); - vfio_device_close(device, device->group->iommufd); + vfio_df_close(df); + df->iommufd = NULL; if (device->open_count == 0) vfio_device_put_kvm(device); @@ -218,19 +252,28 @@ void vfio_device_group_close(struct vfio_device *device) static struct file *vfio_device_open_file(struct vfio_device *device) { + struct vfio_device_file *df; struct file *filep; int ret; - ret = vfio_device_group_open(device); - if (ret) + df = vfio_allocate_device_file(device); + if (IS_ERR(df)) { + ret = PTR_ERR(df); goto err_out; + } + + df->group = device->group; + + ret = vfio_df_group_open(df); + if (ret) + goto err_free; /* * We can't use anon_inode_getfd() because we need to modify * the f_mode flags directly to allow more than just ioctls */ filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops, - device, O_RDWR); + df, O_RDWR); if (IS_ERR(filep)) { ret = PTR_ERR(filep); goto err_close_device; @@ -253,7 +296,9 @@ static struct file *vfio_device_open_file(struct vfio_device *device) return filep; err_close_device: - vfio_device_group_close(device); + vfio_df_group_close(df); +err_free: + kfree(df); err_out: return ERR_PTR(ret); } @@ -357,6 +402,33 @@ static long vfio_group_fops_unl_ioctl(struct file *filep, } } +int vfio_device_block_group(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + int ret = 0; + + mutex_lock(&group->group_lock); + if (group->opened_file) { + ret = -EBUSY; + goto out_unlock; + } + + group->cdev_device_open_cnt++; + +out_unlock: + mutex_unlock(&group->group_lock); + return ret; +} + +void vfio_device_unblock_group(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + + mutex_lock(&group->group_lock); + group->cdev_device_open_cnt--; + mutex_unlock(&group->group_lock); +} + static int vfio_group_fops_open(struct inode *inode, struct file *filep) { struct vfio_group *group = @@ -379,6 +451,11 @@ static int vfio_group_fops_open(struct inode *inode, struct file *filep) goto out_unlock; } + if (group->cdev_device_open_cnt) { + ret = -EBUSY; + goto out_unlock; + } + /* * Do we need multiple instances of the group open? Seems not. */ @@ -453,6 +530,7 @@ static void vfio_group_release(struct device *dev) mutex_destroy(&group->device_lock); mutex_destroy(&group->group_lock); WARN_ON(group->iommu_group); + WARN_ON(group->cdev_device_open_cnt); ida_free(&vfio.group_ida, MINOR(group->dev.devt)); kfree(group); } @@ -604,16 +682,6 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) if (!iommu_group) return ERR_PTR(-EINVAL); - /* - * VFIO always sets IOMMU_CACHE because we offer no way for userspace to - * restore cache coherency. It has to be checked here because it is only - * valid for cases where we are using iommu groups. - */ - if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) { - iommu_group_put(iommu_group); - return ERR_PTR(-EINVAL); - } - mutex_lock(&vfio.group_lock); group = vfio_group_find_from_iommu(iommu_group); if (group) { @@ -745,6 +813,15 @@ bool vfio_device_has_container(struct vfio_device *device) return device->group->container; } +struct vfio_group *vfio_group_from_file(struct file *file) +{ + struct vfio_group *group = file->private_data; + + if (file->f_op != &vfio_group_fops) + return NULL; + return group; +} + /** * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file * @file: VFIO group file @@ -755,13 +832,13 @@ bool vfio_device_has_container(struct vfio_device *device) */ struct iommu_group *vfio_file_iommu_group(struct file *file) { - struct vfio_group *group = file->private_data; + struct vfio_group *group = vfio_group_from_file(file); struct iommu_group *iommu_group = NULL; if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU)) return NULL; - if (!vfio_file_is_group(file)) + if (!group) return NULL; mutex_lock(&group->group_lock); @@ -775,33 +852,20 @@ struct iommu_group *vfio_file_iommu_group(struct file *file) EXPORT_SYMBOL_GPL(vfio_file_iommu_group); /** - * vfio_file_is_group - True if the file is usable with VFIO aPIS + * vfio_file_is_group - True if the file is a vfio group file * @file: VFIO group file */ bool vfio_file_is_group(struct file *file) { - return file->f_op == &vfio_group_fops; + return vfio_group_from_file(file); } EXPORT_SYMBOL_GPL(vfio_file_is_group); -/** - * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file - * is always CPU cache coherent - * @file: VFIO group file - * - * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop - * bit in DMA transactions. A return of false indicates that the user has - * rights to access additional instructions such as wbinvd on x86. - */ -bool vfio_file_enforced_coherent(struct file *file) +bool vfio_group_enforced_coherent(struct vfio_group *group) { - struct vfio_group *group = file->private_data; struct vfio_device *device; bool ret = true; - if (!vfio_file_is_group(file)) - return true; - /* * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then * any domain later attached to it will also not support it. If the cap @@ -819,28 +883,13 @@ bool vfio_file_enforced_coherent(struct file *file) mutex_unlock(&group->device_lock); return ret; } -EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent); -/** - * vfio_file_set_kvm - Link a kvm with VFIO drivers - * @file: VFIO group file - * @kvm: KVM to link - * - * When a VFIO device is first opened the KVM will be available in - * device->kvm if one was associated with the group. - */ -void vfio_file_set_kvm(struct file *file, struct kvm *kvm) +void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm) { - struct vfio_group *group = file->private_data; - - if (!vfio_file_is_group(file)) - return; - spin_lock(&group->kvm_ref_lock); group->kvm = kvm; spin_unlock(&group->kvm_ref_lock); } -EXPORT_SYMBOL_GPL(vfio_file_set_kvm); /** * vfio_file_has_dev - True if the VFIO file is a handle for device @@ -851,9 +900,9 @@ EXPORT_SYMBOL_GPL(vfio_file_set_kvm); */ bool vfio_file_has_dev(struct file *file, struct vfio_device *device) { - struct vfio_group *group = file->private_data; + struct vfio_group *group = vfio_group_from_file(file); - if (!vfio_file_is_group(file)) + if (!group) return false; return group == device->group; |