Hi Yi, On 7/28/20 8:27 AM, Liu Yi L 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> > --- > 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 | 161 ++++++++++++++++++++++++++++++++++++++++ > drivers/vfio/vfio_pasid.c | 26 +++++++ > include/linux/vfio.h | 20 +++++ > include/uapi/linux/vfio.h | 31 ++++++++ > 4 files changed, 238 insertions(+) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index ea89c7c..245436e 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -149,6 +149,36 @@ 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; You may add a bool indicating whether the data is a user pointer or the direct IOMMU UAPI struct. > +}; > + > +/* iommu->lock must be held */ > +static int vfio_get_nesting_domain_capsule(struct vfio_iommu *iommu, > + struct domain_capsule *dc) I would rename the function into vfio_prepare_nesting_domain_capsule > +{ > + struct vfio_domain *domain = NULL; > + struct vfio_group *group = NULL; > + > + if (!iommu->nesting_info) > + return -EINVAL; > + > + /* > + * Only support singleton container with nesting type. > + * If nesting_info is non-NULL, the conatiner should s/should/is here and below s/conatiner/container > + * be non-empty. Also domain should be 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, > @@ -2349,6 +2379,48 @@ 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_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; > + unsigned long arg = *(unsigned long *)dc->data; > + > + iommu_uapi_sva_unbind_gpasid(dc->domain, dev, (void __user *)arg); > + return 0; > +} > + > +static int __vfio_dev_unbind_gpasid_fn(struct device *dev, void *data) can be removed if dc->user flag gets added > +{ > + 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); I do not remember to have seen this documented anywhere, ie. on unbind, the vendor data are not used. > + 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) > { > @@ -2392,6 +2464,21 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, > if (!group) > continue; > > + if (iommu->nesting_info && iommu->vmm && if vmm is set, doesn't it mean nesting_info is set? > + (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); > @@ -2926,6 +3013,78 @@ 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) { Is it documented anywhere, besides in this commit message that IOMMU_NESTING_FEAT_BIND_PGTBL requires IOMMU_NESTING_FEAT_SYSWIDE_PASID (in uapi doc)? > + ret = -EINVAL; > + goto out_unlock; > + } > + > + ret = vfio_get_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); > + > + ret = 0; non needed > + 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); > + ret = 0; ret is not correct in case bind previously failed. You should return the original ret in that case. > + } > + > + 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) Checking against VFIO_NESTING_OP_MASK is not enough precise enough (I mean OP_MASK should only encompasses the actual supported ops). If a a userspace tries to use a new OP in the future and if this runs on this kernel version, you will fait to recognize the lack of support. > + 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) > { > @@ -2944,6 +3103,8 @@ 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 8d0317f..e531d4a 100644 > --- a/drivers/vfio/vfio_pasid.c > +++ b/drivers/vfio/vfio_pasid.c > @@ -221,6 +221,8 @@ 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) > @@ -229,6 +231,30 @@ 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_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_mm_lock); > diff --git a/include/linux/vfio.h b/include/linux/vfio.h > index a355d01..e835c23 100644 > --- a/include/linux/vfio.h > +++ b/include/linux/vfio.h > @@ -105,6 +105,11 @@ extern 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 6d79557..9501cfb 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -1209,6 +1209,37 @@ 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. PASID alloc/free are handled through another IOCTL so you should be more precise I think. > + * > + * @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 -------- */ > > /* > Thanks Eric
