| Message ID | 20230309080910.607396-5-yi.l.liu@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | iommufd: Add nesting infrastructure | expand |
On 3/9/23 4:09 PM, Yi Liu wrote: > Nested translation has stage-1 and stage-2 page tables. A stage-1 page > table is managed by user space, and it needs to work with a stage-2 page > table, which is a parent hwpt for the stage-1 hwpt. > > iommu core already supports accepting parent iommu_domain and user_data > to allocate an iommu_domain. This makes iommufd_hw_pagetable_alloc() to > accept the parent hwpt and user_data, and relays them to iommu core, to > prepare for supporting hw_pagetable allocation with user_data. > > Also, add a parent pointer in struct iommufd_hw_pagetable for taking and > releasing its refcount. > > Co-developed-by: Nicolin Chen <nicolinc@nvidia.com> > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> > Signed-off-by: Yi Liu <yi.l.liu@intel.com> > --- > drivers/iommu/iommufd/device.c | 2 +- > drivers/iommu/iommufd/hw_pagetable.c | 28 ++++++++++++++++++++++--- > drivers/iommu/iommufd/iommufd_private.h | 5 ++++- > 3 files changed, 30 insertions(+), 5 deletions(-) > > diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c > index 5c352807d946..19cd6df46c6a 100644 > --- a/drivers/iommu/iommufd/device.c > +++ b/drivers/iommu/iommufd/device.c > @@ -558,7 +558,7 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev, > } > > hwpt = iommufd_hw_pagetable_alloc(idev->ictx, ioas, idev, > - immediate_attach); > + NULL, NULL, immediate_attach); > if (IS_ERR(hwpt)) { > destroy_hwpt = ERR_CAST(hwpt); > goto out_unlock; > diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c > index 84b4a11e62f8..16e92a1c150b 100644 > --- a/drivers/iommu/iommufd/hw_pagetable.c > +++ b/drivers/iommu/iommufd/hw_pagetable.c > @@ -24,6 +24,8 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj) > if (hwpt->domain) > iommu_domain_free(hwpt->domain); > > + if (hwpt->parent) > + refcount_dec(&hwpt->parent->obj.users); > refcount_dec(&hwpt->ioas->obj.users); > } > > @@ -46,6 +48,8 @@ int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt) > * @ictx: iommufd context > * @ioas: IOAS to associate the domain with > * @idev: Device to get an iommu_domain for > + * @parent: Optional parent HWPT to associate with the domain with > + * @user_data: Optional user_data pointer > * @immediate_attach: True if idev should be attached to the hwpt > * > * Allocate a new iommu_domain and return it as a hw_pagetable. The HWPT > @@ -54,14 +58,20 @@ int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt) > */ > struct iommufd_hw_pagetable * > iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, > - struct iommufd_device *idev, bool immediate_attach) > + struct iommufd_device *idev, > + struct iommufd_hw_pagetable *parent, > + void *user_data, bool immediate_attach) > { > const struct iommu_ops *ops = dev_iommu_ops(idev->dev); > + struct iommu_domain *parent_domain = NULL; > struct iommufd_hw_pagetable *hwpt; > int rc; > > lockdep_assert_held(&ioas->mutex); > > + if (parent && !ops->domain_alloc_user) > + return ERR_PTR(-EOPNOTSUPP); My understanding here is that we are checking whether domain_alloc_user is required. It seems that as long as the caller inputs a valid user_data or parent, domain_alloc_user is required. If so, if ((user_data || parent) && !ops->domain_alloc_user) return ERR_PTR(-EOPNOTSUPP); Best regards, baolu
On Fri, Mar 10, 2023 at 10:10:56AM +0800, Baolu Lu wrote: > > @@ -54,14 +58,20 @@ int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt) > > */ > > struct iommufd_hw_pagetable * > > iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, > > - struct iommufd_device *idev, bool immediate_attach) > > + struct iommufd_device *idev, > > + struct iommufd_hw_pagetable *parent, > > + void *user_data, bool immediate_attach) > > { > > const struct iommu_ops *ops = dev_iommu_ops(idev->dev); > > + struct iommu_domain *parent_domain = NULL; > > struct iommufd_hw_pagetable *hwpt; > > int rc; > > lockdep_assert_held(&ioas->mutex); > > + if (parent && !ops->domain_alloc_user) > > + return ERR_PTR(-EOPNOTSUPP); > > My understanding here is that we are checking whether domain_alloc_user > is required. It seems that as long as the caller inputs a valid > user_data or parent, domain_alloc_user is required. If so, > > if ((user_data || parent) && !ops->domain_alloc_user) > return ERR_PTR(-EOPNOTSUPP); Yes Jason
> From: Liu, Yi L <yi.l.liu@intel.com> > Sent: Thursday, March 9, 2023 4:09 PM > > + /* It must be either NESTED or UNMANAGED, depending on > parent_domain */ > + if ((parent_domain && hwpt->domain->type != > IOMMU_DOMAIN_NESTED) || > + (!parent_domain && hwpt->domain->type != > IOMMU_DOMAIN_UNMANAGED)) > + goto out_abort; > + WARN_ON()
On Fri, Mar 17, 2023 at 10:23:54AM +0000, Tian, Kevin wrote: > > From: Liu, Yi L <yi.l.liu@intel.com> > > Sent: Thursday, March 9, 2023 4:09 PM > > > > + /* It must be either NESTED or UNMANAGED, depending on > > parent_domain */ > > + if ((parent_domain && hwpt->domain->type != > > IOMMU_DOMAIN_NESTED) || > > + (!parent_domain && hwpt->domain->type != > > IOMMU_DOMAIN_UNMANAGED)) > > + goto out_abort; > > + > > WARN_ON() Wouldn't that be userspace triggerable? It gets to pick the hwpt used. Jason
> From: Jason Gunthorpe <jgg@nvidia.com> > Sent: Monday, March 20, 2023 8:47 PM > > On Fri, Mar 17, 2023 at 10:23:54AM +0000, Tian, Kevin wrote: > > > From: Liu, Yi L <yi.l.liu@intel.com> > > > Sent: Thursday, March 9, 2023 4:09 PM > > > > > > + /* It must be either NESTED or UNMANAGED, depending on > > > parent_domain */ > > > + if ((parent_domain && hwpt->domain->type != > > > IOMMU_DOMAIN_NESTED) || > > > + (!parent_domain && hwpt->domain->type != > > > IOMMU_DOMAIN_UNMANAGED)) > > > + goto out_abort; > > > + > > > > WARN_ON() > > Wouldn't that be userspace triggerable? It gets to pick the hwpt used. > The domain type is set by iommu driver instead of userspace. A sane driver should pass above check, if it claims to support nested.
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 5c352807d946..19cd6df46c6a 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -558,7 +558,7 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev, } hwpt = iommufd_hw_pagetable_alloc(idev->ictx, ioas, idev, - immediate_attach); + NULL, NULL, immediate_attach); if (IS_ERR(hwpt)) { destroy_hwpt = ERR_CAST(hwpt); goto out_unlock; diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 84b4a11e62f8..16e92a1c150b 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -24,6 +24,8 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj) if (hwpt->domain) iommu_domain_free(hwpt->domain); + if (hwpt->parent) + refcount_dec(&hwpt->parent->obj.users); refcount_dec(&hwpt->ioas->obj.users); } @@ -46,6 +48,8 @@ int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt) * @ictx: iommufd context * @ioas: IOAS to associate the domain with * @idev: Device to get an iommu_domain for + * @parent: Optional parent HWPT to associate with the domain with + * @user_data: Optional user_data pointer * @immediate_attach: True if idev should be attached to the hwpt * * Allocate a new iommu_domain and return it as a hw_pagetable. The HWPT @@ -54,14 +58,20 @@ int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt) */ struct iommufd_hw_pagetable * iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, - struct iommufd_device *idev, bool immediate_attach) + struct iommufd_device *idev, + struct iommufd_hw_pagetable *parent, + void *user_data, bool immediate_attach) { const struct iommu_ops *ops = dev_iommu_ops(idev->dev); + struct iommu_domain *parent_domain = NULL; struct iommufd_hw_pagetable *hwpt; int rc; lockdep_assert_held(&ioas->mutex); + if (parent && !ops->domain_alloc_user) + return ERR_PTR(-EOPNOTSUPP); + hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE); if (IS_ERR(hwpt)) return hwpt; @@ -70,9 +80,15 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, /* Pairs with iommufd_hw_pagetable_destroy() */ refcount_inc(&ioas->obj.users); hwpt->ioas = ioas; + if (parent) { + hwpt->parent = parent; + parent_domain = parent->domain; + refcount_inc(&parent->obj.users); + } if (ops->domain_alloc_user) - hwpt->domain = ops->domain_alloc_user(idev->dev, NULL, NULL); + hwpt->domain = ops->domain_alloc_user(idev->dev, + parent_domain, user_data); else hwpt->domain = iommu_domain_alloc(idev->dev->bus); if (!hwpt->domain) { @@ -80,6 +96,11 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, goto out_abort; } + /* It must be either NESTED or UNMANAGED, depending on parent_domain */ + if ((parent_domain && hwpt->domain->type != IOMMU_DOMAIN_NESTED) || + (!parent_domain && hwpt->domain->type != IOMMU_DOMAIN_UNMANAGED)) + goto out_abort; + /* * Set the coherency mode before we do iopt_table_add_domain() as some * iommus have a per-PTE bit that controls it and need to decide before @@ -150,7 +171,8 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) } mutex_lock(&ioas->mutex); - hwpt = iommufd_hw_pagetable_alloc(ucmd->ictx, ioas, idev, false); + hwpt = iommufd_hw_pagetable_alloc(ucmd->ictx, ioas, idev, + NULL, NULL, false); mutex_unlock(&ioas->mutex); if (IS_ERR(hwpt)) { rc = PTR_ERR(hwpt); diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 05b5ad66f716..182c074eecdc 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -243,6 +243,7 @@ int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd); */ struct iommufd_hw_pagetable { struct iommufd_object obj; + struct iommufd_hw_pagetable *parent; struct iommufd_ioas *ioas; struct iommu_domain *domain; bool auto_domain : 1; @@ -254,7 +255,9 @@ struct iommufd_hw_pagetable { struct iommufd_hw_pagetable * iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, - struct iommufd_device *idev, bool immediate_attach); + struct iommufd_device *idev, + struct iommufd_hw_pagetable *parent, + void *user_data, bool immediate_attach); int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt); int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, struct iommufd_device *idev);