On Thu, 10 Sep 2020 03:45:27 -0700 Liu Yi L <yi.l.liu@xxxxxxxxx> wrote: > Nesting translation allows two-levels/stages page tables, with 1st level > for guest translations (e.g. GVA->GPA), 2nd level for host translations > (e.g. GPA->HPA). This patch adds interface for binding guest page tables > to a PASID. This PASID must have been allocated by the userspace before > the binding request. > > Cc: Kevin Tian <kevin.tian@xxxxxxxxx> > CC: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> > Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> > Cc: Eric Auger <eric.auger@xxxxxxxxxx> > Cc: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> > Cc: Joerg Roedel <joro@xxxxxxxxxx> > Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx> > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx> > Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> > --- > v6 -> v7: > *) introduced @user in struct domain_capsule to simplify the code per Eric's > suggestion. > *) introduced VFIO_IOMMU_NESTING_OP_NUM for sanitizing op from userspace. > *) corrected the @argsz value of unbind_data in vfio_group_unbind_gpasid_fn(). > > v5 -> v6: > *) dropped vfio_find_nesting_group() and add vfio_get_nesting_domain_capsule(). > per comment from Eric. > *) use iommu_uapi_sva_bind/unbind_gpasid() and iommu_sva_unbind_gpasid() in > linux/iommu.h for userspace operation and in-kernel operation. > > v3 -> v4: > *) address comments from Alex on v3 > > v2 -> v3: > *) use __iommu_sva_unbind_gpasid() for unbind call issued by VFIO > https://lore.kernel.org/linux-iommu/1592931837-58223-6-git-send-email-jacob.jun.pan@xxxxxxxxxxxxxxx/ > > v1 -> v2: > *) rename subject from "vfio/type1: Bind guest page tables to host" > *) remove VFIO_IOMMU_BIND, introduce VFIO_IOMMU_NESTING_OP to support bind/ > unbind guet page table > *) replaced vfio_iommu_for_each_dev() with a group level loop since this > series enforces one group per container w/ nesting type as start. > *) rename vfio_bind/unbind_gpasid_fn() to vfio_dev_bind/unbind_gpasid_fn() > *) vfio_dev_unbind_gpasid() always successful > *) use vfio_mm->pasid_lock to avoid race between PASID free and page table > bind/unbind > --- > drivers/vfio/vfio_iommu_type1.c | 163 ++++++++++++++++++++++++++++++++++++++++ > drivers/vfio/vfio_pasid.c | 26 +++++++ > include/linux/vfio.h | 20 +++++ > include/uapi/linux/vfio.h | 36 +++++++++ > 4 files changed, 245 insertions(+) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index bd4b668..11f1156 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -149,6 +149,39 @@ struct vfio_regions { > #define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX) > #define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX) > > +struct domain_capsule { > + struct vfio_group *group; > + struct iommu_domain *domain; > + /* set if @data contains a user pointer*/ > + bool user; > + void *data; > +}; Put the hole in the structure at the end, but I suspect we might lose the user field when the internal api drops the unnecessary structure for unbind anyway. > + > +/* iommu->lock must be held */ > +static int vfio_prepare_nesting_domain_capsule(struct vfio_iommu *iommu, > + struct domain_capsule *dc) > +{ > + struct vfio_domain *domain = NULL; > + struct vfio_group *group = NULL; Unnecessary initialization. > + > + if (!iommu->nesting_info) > + return -EINVAL; > + > + /* > + * Only support singleton container with nesting type. If > + * nesting_info is non-NULL, the container is non-empty. > + * Also domain is non-empty. > + */ > + domain = list_first_entry(&iommu->domain_list, > + struct vfio_domain, next); > + group = list_first_entry(&domain->group_list, > + struct vfio_group, next); > + dc->group = group; > + dc->domain = domain->domain; > + dc->user = true; > + return 0; > +} > + > static int put_pfn(unsigned long pfn, int prot); > > static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu, > @@ -2405,6 +2438,49 @@ static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu, > return ret; > } > > +static int vfio_dev_bind_gpasid_fn(struct device *dev, void *data) > +{ > + struct domain_capsule *dc = (struct domain_capsule *)data; > + unsigned long arg = *(unsigned long *)dc->data; > + > + return iommu_uapi_sva_bind_gpasid(dc->domain, dev, > + (void __user *)arg); > +} > + > +static int vfio_dev_unbind_gpasid_fn(struct device *dev, void *data) > +{ > + struct domain_capsule *dc = (struct domain_capsule *)data; > + > + if (dc->user) { > + unsigned long arg = *(unsigned long *)dc->data; > + > + iommu_uapi_sva_unbind_gpasid(dc->domain, > + dev, (void __user *)arg); > + } else { > + struct iommu_gpasid_bind_data *unbind_data = > + (struct iommu_gpasid_bind_data *)dc->data; > + > + iommu_sva_unbind_gpasid(dc->domain, dev, unbind_data); > + } > + return 0; > +} > + > +static void vfio_group_unbind_gpasid_fn(ioasid_t pasid, void *data) > +{ > + struct domain_capsule *dc = (struct domain_capsule *)data; > + struct iommu_gpasid_bind_data unbind_data; > + > + unbind_data.argsz = sizeof(struct iommu_gpasid_bind_data); > + unbind_data.flags = 0; > + unbind_data.hpasid = pasid; As in thread with Jacob, this all seems a little excessive for an internal api callback that requires one arg. > + > + dc->user = false; > + dc->data = &unbind_data; > + > + iommu_group_for_each_dev(dc->group->iommu_group, > + dc, vfio_dev_unbind_gpasid_fn); > +} > + > static void vfio_iommu_type1_detach_group(void *iommu_data, > struct iommu_group *iommu_group) > { > @@ -2448,6 +2524,20 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, > if (!group) > continue; > > + if (iommu->vmm && (iommu->nesting_info->features & > + IOMMU_NESTING_FEAT_BIND_PGTBL)) { > + struct domain_capsule dc = { .group = group, > + .domain = domain->domain, > + .data = NULL }; > + > + /* > + * Unbind page tables bound with system wide PASIDs > + * which are allocated to userspace. > + */ > + vfio_mm_for_each_pasid(iommu->vmm, &dc, > + vfio_group_unbind_gpasid_fn); > + } > + > vfio_iommu_detach_group(domain, group); > update_dirty_scope = !group->pinned_page_dirty_scope; > list_del(&group->next); > @@ -2982,6 +3072,77 @@ static int vfio_iommu_type1_pasid_request(struct vfio_iommu *iommu, > return ret; > } > > +static long vfio_iommu_handle_pgtbl_op(struct vfio_iommu *iommu, > + bool is_bind, unsigned long arg) > +{ > + struct domain_capsule dc = { .data = &arg }; > + struct iommu_nesting_info *info; > + int ret; > + > + mutex_lock(&iommu->lock); > + > + info = iommu->nesting_info; > + if (!info || !(info->features & IOMMU_NESTING_FEAT_BIND_PGTBL)) { > + ret = -EOPNOTSUPP; > + goto out_unlock; > + } > + > + if (!iommu->vmm) { > + ret = -EINVAL; > + goto out_unlock; > + } > + > + ret = vfio_prepare_nesting_domain_capsule(iommu, &dc); > + if (ret) > + goto out_unlock; > + > + /* Avoid race with other containers within the same process */ > + vfio_mm_pasid_lock(iommu->vmm); > + > + if (is_bind) > + ret = iommu_group_for_each_dev(dc.group->iommu_group, &dc, > + vfio_dev_bind_gpasid_fn); > + if (ret || !is_bind) > + iommu_group_for_each_dev(dc.group->iommu_group, > + &dc, vfio_dev_unbind_gpasid_fn); > + > + vfio_mm_pasid_unlock(iommu->vmm); > +out_unlock: > + mutex_unlock(&iommu->lock); > + return ret; > +} > + > +static long vfio_iommu_type1_nesting_op(struct vfio_iommu *iommu, > + unsigned long arg) > +{ > + struct vfio_iommu_type1_nesting_op hdr; > + unsigned int minsz; > + int ret; > + > + minsz = offsetofend(struct vfio_iommu_type1_nesting_op, flags); > + > + if (copy_from_user(&hdr, (void __user *)arg, minsz)) > + return -EFAULT; > + > + if (hdr.argsz < minsz || > + hdr.flags & ~VFIO_NESTING_OP_MASK || > + (hdr.flags & VFIO_NESTING_OP_MASK) >= VFIO_IOMMU_NESTING_OP_NUM) Isn't this redundant to the default switch case? > + return -EINVAL; > + > + switch (hdr.flags & VFIO_NESTING_OP_MASK) { > + case VFIO_IOMMU_NESTING_OP_BIND_PGTBL: > + ret = vfio_iommu_handle_pgtbl_op(iommu, true, arg + minsz); > + break; > + case VFIO_IOMMU_NESTING_OP_UNBIND_PGTBL: > + ret = vfio_iommu_handle_pgtbl_op(iommu, false, arg + minsz); > + break; > + default: > + ret = -EINVAL; > + } > + > + return ret; > +} > + > static long vfio_iommu_type1_ioctl(void *iommu_data, > unsigned int cmd, unsigned long arg) > { > @@ -3000,6 +3161,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, > return vfio_iommu_type1_dirty_pages(iommu, arg); > case VFIO_IOMMU_PASID_REQUEST: > return vfio_iommu_type1_pasid_request(iommu, arg); > + case VFIO_IOMMU_NESTING_OP: > + return vfio_iommu_type1_nesting_op(iommu, arg); > default: > return -ENOTTY; > } > diff --git a/drivers/vfio/vfio_pasid.c b/drivers/vfio/vfio_pasid.c > index 0ec4660..9e2e4b0 100644 > --- a/drivers/vfio/vfio_pasid.c > +++ b/drivers/vfio/vfio_pasid.c > @@ -220,6 +220,8 @@ void vfio_pasid_free_range(struct vfio_mm *vmm, > * IOASID core will notify PASID users (e.g. IOMMU driver) to > * teardown necessary structures depending on the to-be-freed > * PASID. > + * Hold pasid_lock also avoids race with PASID usages like bind/ > + * unbind page tables to requested PASID. > */ > mutex_lock(&vmm->pasid_lock); > while ((vid = vfio_find_pasid(vmm, min, max)) != NULL) > @@ -228,6 +230,30 @@ void vfio_pasid_free_range(struct vfio_mm *vmm, > } > EXPORT_SYMBOL_GPL(vfio_pasid_free_range); > > +int vfio_mm_for_each_pasid(struct vfio_mm *vmm, void *data, > + void (*fn)(ioasid_t id, void *data)) > +{ > + int ret; > + > + mutex_lock(&vmm->pasid_lock); > + ret = ioasid_set_for_each_ioasid(vmm->ioasid_set, fn, data); > + mutex_unlock(&vmm->pasid_lock); > + return ret; > +} > +EXPORT_SYMBOL_GPL(vfio_mm_for_each_pasid); > + > +void vfio_mm_pasid_lock(struct vfio_mm *vmm) > +{ > + mutex_lock(&vmm->pasid_lock); > +} > +EXPORT_SYMBOL_GPL(vfio_mm_pasid_lock); > + > +void vfio_mm_pasid_unlock(struct vfio_mm *vmm) > +{ > + mutex_unlock(&vmm->pasid_lock); > +} > +EXPORT_SYMBOL_GPL(vfio_mm_pasid_unlock); > + > static int __init vfio_pasid_init(void) > { > mutex_init(&vfio_mm_lock); > diff --git a/include/linux/vfio.h b/include/linux/vfio.h > index 5c3d7a8..6a999c3 100644 > --- a/include/linux/vfio.h > +++ b/include/linux/vfio.h > @@ -105,6 +105,11 @@ extern struct ioasid_set *vfio_mm_ioasid_set(struct vfio_mm *vmm); > extern int vfio_pasid_alloc(struct vfio_mm *vmm, int min, int max); > extern void vfio_pasid_free_range(struct vfio_mm *vmm, > ioasid_t min, ioasid_t max); > +extern int vfio_mm_for_each_pasid(struct vfio_mm *vmm, void *data, > + void (*fn)(ioasid_t id, void *data)); > +extern void vfio_mm_pasid_lock(struct vfio_mm *vmm); > +extern void vfio_mm_pasid_unlock(struct vfio_mm *vmm); > + > #else > static inline struct vfio_mm *vfio_mm_get_from_task(struct task_struct *task) > { > @@ -129,6 +134,21 @@ static inline void vfio_pasid_free_range(struct vfio_mm *vmm, > ioasid_t min, ioasid_t max) > { > } > + > +static inline int vfio_mm_for_each_pasid(struct vfio_mm *vmm, void *data, > + void (*fn)(ioasid_t id, void *data)) > +{ > + return -ENOTTY; > +} > + > +static inline void vfio_mm_pasid_lock(struct vfio_mm *vmm) > +{ > +} > + > +static inline void vfio_mm_pasid_unlock(struct vfio_mm *vmm) > +{ > +} > + > #endif /* CONFIG_VFIO_PASID */ > > /* > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index a4bc42e..a99bd71 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -1215,6 +1215,42 @@ struct vfio_iommu_type1_pasid_request { > > #define VFIO_IOMMU_PASID_REQUEST _IO(VFIO_TYPE, VFIO_BASE + 18) > > +/** > + * VFIO_IOMMU_NESTING_OP - _IOW(VFIO_TYPE, VFIO_BASE + 19, > + * struct vfio_iommu_type1_nesting_op) > + * > + * This interface allows userspace to utilize the nesting IOMMU > + * capabilities as reported in VFIO_IOMMU_TYPE1_INFO_CAP_NESTING > + * cap through VFIO_IOMMU_GET_INFO. For platforms which require > + * system wide PASID, PASID will be allocated by VFIO_IOMMU_PASID > + * _REQUEST. > + * > + * @data[] types defined for each op: > + * +=================+===============================================+ > + * | NESTING OP | @data[] | > + * +=================+===============================================+ > + * | BIND_PGTBL | struct iommu_gpasid_bind_data | > + * +-----------------+-----------------------------------------------+ > + * | UNBIND_PGTBL | struct iommu_gpasid_bind_data | > + * +-----------------+-----------------------------------------------+ > + * > + * returns: 0 on success, -errno on failure. > + */ > +struct vfio_iommu_type1_nesting_op { > + __u32 argsz; > + __u32 flags; > +#define VFIO_NESTING_OP_MASK (0xffff) /* lower 16-bits for op */ > + __u8 data[]; > +}; > + > +enum { > + VFIO_IOMMU_NESTING_OP_BIND_PGTBL, > + VFIO_IOMMU_NESTING_OP_UNBIND_PGTBL, > + VFIO_IOMMU_NESTING_OP_NUM, > +}; "VFIO_IOMMU_NESTING_NUM_OPS" would be more consistent with the vfio uapi. Thanks, Alex > + > +#define VFIO_IOMMU_NESTING_OP _IO(VFIO_TYPE, VFIO_BASE + 19) > + > /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */ > > /*
