Hi Alex, > From: Alex Williamson <alex.williamson@xxxxxxxxxx> > Sent: Friday, July 3, 2020 5:20 AM > > On Wed, 24 Jun 2020 01:55:22 -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 to > > user space 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> > > --- > > 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 | 169 > ++++++++++++++++++++++++++++++++++++++++ > > drivers/vfio/vfio_pasid.c | 30 +++++++ > > include/linux/vfio.h | 20 +++++ > > include/uapi/linux/vfio.h | 30 +++++++ > > 4 files changed, 249 insertions(+) > > > > diff --git a/drivers/vfio/vfio_iommu_type1.c > > b/drivers/vfio/vfio_iommu_type1.c index d0891c5..5926533 100644 > > --- a/drivers/vfio/vfio_iommu_type1.c > > +++ b/drivers/vfio/vfio_iommu_type1.c > > @@ -148,6 +148,33 @@ 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; > > + void *data; > > +}; > > + > > +/* iommu->lock must be held */ > > +static struct vfio_group *vfio_find_nesting_group(struct vfio_iommu > > +*iommu) { > > + struct vfio_domain *d; > > + struct vfio_group *g, *group = NULL; > > + > > + if (!iommu->nesting_info) > > + return NULL; > > + > > + /* only support singleton container with nesting type */ > > + list_for_each_entry(d, &iommu->domain_list, next) { > > + list_for_each_entry(g, &d->group_list, next) { > > + if (!group) { > > + group = g; > > + break; > > + } > > > We break out of the inner loop only to pointlessly continue in the outer loop > when we could simply return g and remove the second group pointer altogether > (use "group" instead of "g" if so). how about below? :-) /* only support singleton container with nesting type */ list_for_each_entry(d, &iommu->domain_list, next) { list_for_each_entry(group, &d->group_list, next) { break; } } > > > + } > > + } > > + return group; > > +} > > + > > static int put_pfn(unsigned long pfn, int prot); > > > > static struct vfio_group *vfio_iommu_find_iommu_group(struct > > vfio_iommu *iommu, @@ -2351,6 +2378,48 @@ 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_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; > > + unsigned long arg = *(unsigned long *) dc->data; > > + > > + iommu_sva_unbind_gpasid(dc->domain, dev, (void __user *) arg); > > + return 0; > > +} > > + > > +static int __vfio_dev_unbind_gpasid_fn(struct device *dev, void > > +*data) { > > + struct domain_capsule *dc = (struct domain_capsule *)data; > > + 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 = offsetof(struct iommu_gpasid_bind_data, vendor); > > + unbind_data.flags = 0; > > + unbind_data.hpasid = pasid; > > + > > + 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) > { @@ -2394,6 +2463,21 @@ > > static void vfio_iommu_type1_detach_group(void *iommu_data, > > if (!group) > > continue; > > > > + if (iommu->nesting_info && 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 user space. > > + */ > > + 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); > > @@ -2942,6 +3026,89 @@ static int vfio_iommu_type1_pasid_request(struct > vfio_iommu *iommu, > > } > > } > > > > +static long vfio_iommu_handle_pgtbl_op(struct vfio_iommu *iommu, > > + bool is_bind, unsigned long arg) { > > + struct iommu_nesting_info *info; > > + struct domain_capsule dc = { .data = &arg }; > > + struct vfio_group *group; > > + struct vfio_domain *domain; > > + int ret; > > + > > + mutex_lock(&iommu->lock); > > + > > + info = iommu->nesting_info; > > + if (!info || !(info->features & IOMMU_NESTING_FEAT_BIND_PGTBL)) { > > + ret = -ENOTSUPP; > > + goto out_unlock_iommu; > > + } > > + > > + if (!iommu->vmm) { > > + ret = -EINVAL; > > + goto out_unlock_iommu; > > + } > > + > > + group = vfio_find_nesting_group(iommu); > > + if (!group) { > > + ret = -EINVAL; > > + goto out_unlock_iommu; > > + } > > + > > + domain = list_first_entry(&iommu->domain_list, > > + struct vfio_domain, next); > > + dc.group = group; > > + dc.domain = domain->domain; > > + > > + /* Avoid race with other containers within the same process */ > > + vfio_mm_pasid_lock(iommu->vmm); > > + > > + if (is_bind) { > > + ret = iommu_group_for_each_dev(group->iommu_group, &dc, > > + vfio_dev_bind_gpasid_fn); > > + if (ret) > > + iommu_group_for_each_dev(group->iommu_group, > &dc, > > + vfio_dev_unbind_gpasid_fn); > > + } else { > > + iommu_group_for_each_dev(group->iommu_group, > > + &dc, vfio_dev_unbind_gpasid_fn); > > + ret = 0; > > + } > > + > > + vfio_mm_pasid_unlock(iommu->vmm); > > +out_unlock_iommu: > > + 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) > > + 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) { @@ - > 2960,6 +3127,8 @@ > > 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); > > } > > > > return -ENOTTY; > > diff --git a/drivers/vfio/vfio_pasid.c b/drivers/vfio/vfio_pasid.c > > index 2ea9f1a..20f1e72 100644 > > --- a/drivers/vfio/vfio_pasid.c > > +++ b/drivers/vfio/vfio_pasid.c > > @@ -30,6 +30,7 @@ struct vfio_mm { > > struct kref kref; > > struct vfio_mm_token token; > > int ioasid_sid; > > + struct mutex pasid_lock; > > > Introducing holes in the data structure again, mind the alignment. > This wastes 8 byte. Thanks, sure. also it's likely to remove @pasid_quota. so it should avoid the hole as well. Regards, Yi Liu > Alex > > > > int pasid_quota; > > struct list_head next; > > }; > > @@ -97,6 +98,7 @@ struct vfio_mm *vfio_mm_get_from_task(struct > task_struct *task) > > kref_init(&vmm->kref); > > vmm->token.val = (unsigned long long) mm; > > vmm->pasid_quota = pasid_quota; > > + mutex_init(&vmm->pasid_lock); > > > > list_add(&vmm->next, &vfio_pasid.vfio_mm_list); > > out: > > @@ -134,12 +136,40 @@ 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 to avoid race with PASID usages like bind/ > > + * unbind page tables to requested PASID. > > */ > > + mutex_lock(&vmm->pasid_lock); > > for (; pasid <= max; pasid++) > > ioasid_free(pasid); > > + mutex_unlock(&vmm->pasid_lock); > > } > > 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_sid, 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_pasid.vfio_mm_lock); > > diff --git a/include/linux/vfio.h b/include/linux/vfio.h index > > 8e60a32..9028a09 100644 > > --- a/include/linux/vfio.h > > +++ b/include/linux/vfio.h > > @@ -105,6 +105,11 @@ int vfio_mm_ioasid_sid(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 657b2db..2c9def8 100644 > > --- a/include/uapi/linux/vfio.h > > +++ b/include/uapi/linux/vfio.h > > @@ -1198,6 +1198,36 @@ 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 user space to utilize the nesting IOMMU > > + * capabilities as reported through VFIO_IOMMU_GET_INFO. > > + * > > + * @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[]; > > +}; > > + > > +#define VFIO_IOMMU_NESTING_OP_BIND_PGTBL (0) > > +#define VFIO_IOMMU_NESTING_OP_UNBIND_PGTBL (1) > > + > > +#define VFIO_IOMMU_NESTING_OP _IO(VFIO_TYPE, > VFIO_BASE + 19) > > + > > /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU > > -------- */ > > > > /*
