From b2f44814680b569be98e58111bd582fd3a689d4d Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Tue, 6 Aug 2024 17:34:46 -0700 Subject: [PATCH] iommufd/device: Enforce reserved IOVA also when attached to hwpt_nested Currently, device reserved regions are only enforced when the device is attached to an hwpt_paging. In other words, if the device gets attached to an hwpt_nested directly, the parent hwpt_paging of the hwpt_nested's would not enforce those reserved IOVAs. This works for most of reserved region types, but not for IOMMU_RESV_SW_MSI, which is a unique software defined window, required by a nesting case too to setup an MSI doorbell on the parent stage-2 hwpt/domain. Kevin pointed out in 1 that: 1) there is no usage using up closely the entire IOVA space yet, 2) guest may change the viommu mode to switch between nested and paging then VMM has to take all devices' reserved regions into consideration anyway, when composing the GPA space. So it would be actually convenient for us to also enforce reserved IOVA onto the parent hwpt_paging, when attaching a device to an hwpt_nested. Repurpose the existing attach/replace_paging helpers to attach device's reserved IOVAs exclusively. Add a new find_hwpt_paging helper, which is only used by these reserved IOVA functions, to allow an IOMMUFD_OBJ_HWPT_NESTED hwpt to redirect to its parent hwpt_paging. Return a NULL in these two helpers for any new HWPT type in the future. Link: https://patch.msgid.link/r/20240807003446.3740368-1-nicolinc@nvidia.com Link: https://lore.kernel.org/all/BN9PR11MB5276497781C96415272E6FED8CB12@BN9PR11MB5276.namprd11.prod.outlook.com/ #1 Suggested-by: Kevin Tian Signed-off-by: Nicolin Chen Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/device.c | 52 ++++++++++++------------- drivers/iommu/iommufd/iommufd_private.h | 19 +++++++++ 2 files changed, 45 insertions(+), 26 deletions(-) diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 3214a4c17c6b3b..bcbcd6d9406240 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -327,8 +327,9 @@ static int iommufd_group_setup_msi(struct iommufd_group *igroup, return 0; } -static int iommufd_hwpt_paging_attach(struct iommufd_hwpt_paging *hwpt_paging, - struct iommufd_device *idev) +static int +iommufd_device_attach_reserved_iova(struct iommufd_device *idev, + struct iommufd_hwpt_paging *hwpt_paging) { int rc; @@ -354,6 +355,7 @@ static int iommufd_hwpt_paging_attach(struct iommufd_hwpt_paging *hwpt_paging, int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, struct iommufd_device *idev) { + struct iommufd_hwpt_paging *hwpt_paging = find_hwpt_paging(hwpt); int rc; mutex_lock(&idev->igroup->lock); @@ -363,8 +365,8 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, goto err_unlock; } - if (hwpt_is_paging(hwpt)) { - rc = iommufd_hwpt_paging_attach(to_hwpt_paging(hwpt), idev); + if (hwpt_paging) { + rc = iommufd_device_attach_reserved_iova(idev, hwpt_paging); if (rc) goto err_unlock; } @@ -387,9 +389,8 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, mutex_unlock(&idev->igroup->lock); return 0; err_unresv: - if (hwpt_is_paging(hwpt)) - iopt_remove_reserved_iova(&to_hwpt_paging(hwpt)->ioas->iopt, - idev->dev); + if (hwpt_paging) + iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, idev->dev); err_unlock: mutex_unlock(&idev->igroup->lock); return rc; @@ -399,6 +400,7 @@ struct iommufd_hw_pagetable * iommufd_hw_pagetable_detach(struct iommufd_device *idev) { struct iommufd_hw_pagetable *hwpt = idev->igroup->hwpt; + struct iommufd_hwpt_paging *hwpt_paging = find_hwpt_paging(hwpt); mutex_lock(&idev->igroup->lock); list_del(&idev->group_item); @@ -406,9 +408,8 @@ iommufd_hw_pagetable_detach(struct iommufd_device *idev) iommufd_hwpt_detach_device(hwpt, idev); idev->igroup->hwpt = NULL; } - if (hwpt_is_paging(hwpt)) - iopt_remove_reserved_iova(&to_hwpt_paging(hwpt)->ioas->iopt, - idev->dev); + if (hwpt_paging) + iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, idev->dev); mutex_unlock(&idev->igroup->lock); /* Caller must destroy hwpt */ @@ -440,17 +441,17 @@ iommufd_group_remove_reserved_iova(struct iommufd_group *igroup, } static int -iommufd_group_do_replace_paging(struct iommufd_group *igroup, - struct iommufd_hwpt_paging *hwpt_paging) +iommufd_group_do_replace_reserved_iova(struct iommufd_group *igroup, + struct iommufd_hwpt_paging *hwpt_paging) { - struct iommufd_hw_pagetable *old_hwpt = igroup->hwpt; + struct iommufd_hwpt_paging *old_hwpt_paging; struct iommufd_device *cur; int rc; lockdep_assert_held(&igroup->lock); - if (!hwpt_is_paging(old_hwpt) || - hwpt_paging->ioas != to_hwpt_paging(old_hwpt)->ioas) { + old_hwpt_paging = find_hwpt_paging(igroup->hwpt); + if (!old_hwpt_paging || hwpt_paging->ioas != old_hwpt_paging->ioas) { list_for_each_entry(cur, &igroup->device_list, group_item) { rc = iopt_table_enforce_dev_resv_regions( &hwpt_paging->ioas->iopt, cur->dev, NULL); @@ -473,6 +474,8 @@ static struct iommufd_hw_pagetable * iommufd_device_do_replace(struct iommufd_device *idev, struct iommufd_hw_pagetable *hwpt) { + struct iommufd_hwpt_paging *hwpt_paging = find_hwpt_paging(hwpt); + struct iommufd_hwpt_paging *old_hwpt_paging; struct iommufd_group *igroup = idev->igroup; struct iommufd_hw_pagetable *old_hwpt; unsigned int num_devices; @@ -491,9 +494,8 @@ iommufd_device_do_replace(struct iommufd_device *idev, } old_hwpt = igroup->hwpt; - if (hwpt_is_paging(hwpt)) { - rc = iommufd_group_do_replace_paging(igroup, - to_hwpt_paging(hwpt)); + if (hwpt_paging) { + rc = iommufd_group_do_replace_reserved_iova(igroup, hwpt_paging); if (rc) goto err_unlock; } @@ -502,11 +504,10 @@ iommufd_device_do_replace(struct iommufd_device *idev, if (rc) goto err_unresv; - if (hwpt_is_paging(old_hwpt) && - (!hwpt_is_paging(hwpt) || - to_hwpt_paging(hwpt)->ioas != to_hwpt_paging(old_hwpt)->ioas)) - iommufd_group_remove_reserved_iova(igroup, - to_hwpt_paging(old_hwpt)); + old_hwpt_paging = find_hwpt_paging(old_hwpt); + if (old_hwpt_paging && + (!hwpt_paging || hwpt_paging->ioas != old_hwpt_paging->ioas)) + iommufd_group_remove_reserved_iova(igroup, old_hwpt_paging); igroup->hwpt = hwpt; @@ -524,9 +525,8 @@ iommufd_device_do_replace(struct iommufd_device *idev, /* Caller must destroy old_hwpt */ return old_hwpt; err_unresv: - if (hwpt_is_paging(hwpt)) - iommufd_group_remove_reserved_iova(igroup, - to_hwpt_paging(hwpt)); + if (hwpt_paging) + iommufd_group_remove_reserved_iova(igroup, hwpt_paging); err_unlock: mutex_unlock(&idev->igroup->lock); return ERR_PTR(rc); diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 92efe30a8f0d00..0bfacaf40c0557 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -324,6 +324,25 @@ to_hwpt_paging(struct iommufd_hw_pagetable *hwpt) return container_of(hwpt, struct iommufd_hwpt_paging, common); } +static inline struct iommufd_hwpt_nested * +to_hwpt_nested(struct iommufd_hw_pagetable *hwpt) +{ + return container_of(hwpt, struct iommufd_hwpt_nested, common); +} + +static inline struct iommufd_hwpt_paging * +find_hwpt_paging(struct iommufd_hw_pagetable *hwpt) +{ + switch (hwpt->obj.type) { + case IOMMUFD_OBJ_HWPT_PAGING: + return to_hwpt_paging(hwpt); + case IOMMUFD_OBJ_HWPT_NESTED: + return to_hwpt_nested(hwpt)->parent; + default: + return NULL; + } +} + static inline struct iommufd_hwpt_paging * iommufd_get_hwpt_paging(struct iommufd_ucmd *ucmd, u32 id) {