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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: fcf8a622-4845-4bb8-0749-08db16c726e4 X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Feb 2023 00:28:01.2181 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: GfMBWOJ/RWCTTNa1LsoQLjPdAMZ7IxjeVJboETLx9IGvcv3mzYlTJx5sgpFegSr8 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB6096 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org When the hwpt to device attachment is fairly static we could get away with the simple approach of keeping track of the groups via a device list. But with replace this is infeasible. Add an automatically managed struct that is 1:1 with the iommu_group per-ictx so we can store the necessary tracking information there. Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/device.c | 128 +++++++++++++++++++++--- drivers/iommu/iommufd/iommufd_private.h | 9 +- drivers/iommu/iommufd/main.c | 2 + 3 files changed, 123 insertions(+), 16 deletions(-) diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 63b65cdfe97f29..d1e227f310e823 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -15,13 +15,110 @@ MODULE_PARM_DESC( "Allow IOMMUFD to bind to devices even if the platform cannot isolate " "the MSI interrupt window. Enabling this is a security weakness."); +static void iommufd_group_release(struct kref *kref) +{ + struct iommufd_group *igroup = + container_of(kref, struct iommufd_group, ref); + + xa_cmpxchg(&igroup->ictx->groups, iommu_group_id(igroup->group), igroup, + NULL, GFP_KERNEL); + iommu_group_put(igroup->group); + kfree(igroup); +} + +static void iommufd_put_group(struct iommufd_group *group) +{ + kref_put(&group->ref, iommufd_group_release); +} + +/* + * iommufd needs to store some more data for each iommu_group, we keep a + * parallel xarray indexed by iommu_group id to hold this instead of putting it + * in the core structure. To keep things simple the iommufd_group memory is + * unique within the iommufd_ctx. This makes it easy to check there are no + * memory leaks. + */ +static struct iommufd_group *iommufd_get_group(struct iommufd_ctx *ictx, + struct device *dev) +{ + struct iommufd_group *new_igroup; + struct iommufd_group *cur_igroup; + struct iommufd_group *igroup; + struct iommu_group *group; + unsigned int id; + + group = iommu_group_get(dev); + if (!group) + return ERR_PTR(-ENODEV); + + id = iommu_group_id(group); + + xa_lock(&ictx->groups); + igroup = xa_load(&ictx->groups, id); + if (igroup && igroup->group == group && + kref_get_unless_zero(&igroup->ref)) { + xa_unlock(&ictx->groups); + iommu_group_put(group); + return igroup; + } + xa_unlock(&ictx->groups); + + new_igroup = kzalloc(sizeof(*new_igroup), GFP_KERNEL); + if (!new_igroup) { + iommu_group_put(group); + return ERR_PTR(-ENOMEM); + } + + kref_init(&new_igroup->ref); + /* group reference moves into new_igroup */ + new_igroup->group = group; + + /* + * All objects using a group reference must put it before their destroy + * completes + */ + new_igroup->ictx = ictx; + + /* + * We dropped the lock so igroup is invalid. Assume that the + * xa had NULL in it, if this guess is wrong then we will obtain + * the actual value under lock and try again once. + */ + cur_igroup = NULL; + xa_lock(&ictx->groups); + while (true) { + igroup = __xa_cmpxchg(&ictx->groups, id, cur_igroup, new_igroup, + GFP_KERNEL); + if (xa_is_err(igroup)) { + xa_unlock(&ictx->groups); + iommufd_put_group(new_igroup); + return ERR_PTR(xa_err(igroup)); + } + + /* new_group was successfully installed */ + if (cur_igroup == igroup) { + xa_unlock(&ictx->groups); + return new_igroup; + } + + /* Check again if the current group is any good */ + if (igroup && igroup->group == group && + kref_get_unless_zero(&igroup->ref)) { + xa_unlock(&ictx->groups); + iommufd_put_group(new_igroup); + return igroup; + } + cur_igroup = igroup; + } +} + void iommufd_device_destroy(struct iommufd_object *obj) { struct iommufd_device *idev = container_of(obj, struct iommufd_device, obj); iommu_device_release_dma_owner(idev->dev); - iommu_group_put(idev->group); + iommufd_put_group(idev->igroup); if (!iommufd_selftest_is_mock_dev(idev->dev)) iommufd_ctx_put(idev->ictx); } @@ -46,7 +143,7 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, struct device *dev, u32 *id) { struct iommufd_device *idev; - struct iommu_group *group; + struct iommufd_group *igroup; int rc; /* @@ -56,9 +153,9 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) return ERR_PTR(-EINVAL); - group = iommu_group_get(dev); - if (!group) - return ERR_PTR(-ENODEV); + igroup = iommufd_get_group(ictx, dev); + if (IS_ERR(igroup)) + return ERR_CAST(igroup); /* * For historical compat with VFIO the insecure interrupt path is @@ -67,7 +164,7 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, * interrupt outside this iommufd context. */ if (!iommufd_selftest_is_mock_dev(dev) && - !iommu_group_has_isolated_msi(group)) { + !iommu_group_has_isolated_msi(igroup->group)) { if (!allow_unsafe_interrupts) { rc = -EPERM; goto out_group_put; @@ -98,7 +195,7 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, /* The calling driver is a user until iommufd_device_unbind() */ refcount_inc(&idev->obj.users); /* group refcount moves into iommufd_device */ - idev->group = group; + idev->igroup = igroup; /* * If the caller fails after this success it must call @@ -113,7 +210,7 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, out_release_owner: iommu_device_release_dma_owner(dev); out_group_put: - iommu_group_put(group); + iommufd_put_group(igroup); return ERR_PTR(rc); } EXPORT_SYMBOL_NS_GPL(iommufd_device_bind, IOMMUFD); @@ -170,14 +267,14 @@ static int iommufd_device_setup_msi(struct iommufd_device *idev, } static bool iommufd_hw_pagetable_has_group(struct iommufd_hw_pagetable *hwpt, - struct iommu_group *group) + struct iommufd_group *igroup) { struct iommufd_device *cur_dev; lockdep_assert_held(&hwpt->devices_lock); list_for_each_entry(cur_dev, &hwpt->devices, devices_item) - if (cur_dev->group == group) + if (cur_dev->igroup->group == igroup->group) return true; return false; } @@ -211,7 +308,8 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, } rc = iopt_table_enforce_group_resv_regions(&hwpt->ioas->iopt, idev->dev, - idev->group, &sw_msi_start); + idev->igroup->group, + &sw_msi_start); if (rc) return rc; @@ -223,8 +321,8 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, * FIXME: Hack around missing a device-centric iommu api, only attach to * the group once for the first device that is in the group. */ - if (!iommufd_hw_pagetable_has_group(hwpt, idev->group)) { - rc = iommu_attach_group(hwpt->domain, idev->group); + if (!iommufd_hw_pagetable_has_group(hwpt, idev->igroup)) { + rc = iommu_attach_group(hwpt->domain, idev->igroup->group); if (rc) goto err_unresv; } @@ -237,8 +335,8 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, void iommufd_hw_pagetable_detach(struct iommufd_hw_pagetable *hwpt, struct iommufd_device *idev) { - if (!iommufd_hw_pagetable_has_group(hwpt, idev->group)) - iommu_detach_group(hwpt->domain, idev->group); + if (!iommufd_hw_pagetable_has_group(hwpt, idev->igroup)) + iommu_detach_group(hwpt->domain, idev->igroup->group); iopt_remove_reserved_iova(&hwpt->ioas->iopt, idev->dev); } diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index d523ef12890e1e..2544f10dae9aef 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -17,6 +17,7 @@ struct iommufd_device; struct iommufd_ctx { struct file *file; struct xarray objects; + struct xarray groups; u8 account_mode; /* Compatibility with VFIO no iommu */ @@ -262,6 +263,12 @@ void iommufd_hw_pagetable_detach(struct iommufd_hw_pagetable *hwpt, struct iommufd_device *idev); void iommufd_hw_pagetable_destroy(struct iommufd_object *obj); +struct iommufd_group { + struct kref ref; + struct iommufd_ctx *ictx; + struct iommu_group *group; +}; + /* * A iommufd_device object represents the binding relationship between a * consuming driver and the iommufd. These objects are created/destroyed by @@ -270,12 +277,12 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj); struct iommufd_device { struct iommufd_object obj; struct iommufd_ctx *ictx; + struct iommufd_group *igroup; struct iommufd_hw_pagetable *hwpt; /* Head at iommufd_hw_pagetable::devices */ struct list_head devices_item; /* always the physical device */ struct device *dev; - struct iommu_group *group; bool enforce_cache_coherency; }; diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 3fbe636c3d8a69..e5ed5dfa91a0b5 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -183,6 +183,7 @@ static int iommufd_fops_open(struct inode *inode, struct file *filp) } xa_init_flags(&ictx->objects, XA_FLAGS_ALLOC1 | XA_FLAGS_ACCOUNT); + xa_init(&ictx->groups); ictx->file = filp; filp->private_data = ictx; return 0; @@ -218,6 +219,7 @@ static int iommufd_fops_release(struct inode *inode, struct file *filp) if (WARN_ON(!destroyed)) break; } + WARN_ON(!xa_empty(&ictx->groups)); kfree(ictx); return 0; }