Jean-Philippe Brucker
2021-Sep-21 16:09 UTC
[PATCH RFC v1 09/11] iommu/virtio: Implement sva bind/unbind calls
On Fri, Apr 23, 2021 at 03:21:45PM +0530, Vivek Gautam wrote:> SVA bind and unbind implementations will allow to prepare translation > context with CPU page tables that can be programmed into host iommu > hardware to realize shared address space utilization between the CPU > and virtualized devices using virtio-iommu. > > Signed-off-by: Vivek Gautam <vivek.gautam at arm.com> > --- > drivers/iommu/virtio-iommu.c | 199 +++++++++++++++++++++++++++++- > include/uapi/linux/virtio_iommu.h | 2 + > 2 files changed, 199 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c > index 250c137a211b..08f1294baeab 100644 > --- a/drivers/iommu/virtio-iommu.c > +++ b/drivers/iommu/virtio-iommu.c > @@ -14,6 +14,9 @@ > #include <linux/interval_tree.h> > #include <linux/iommu.h> > #include <linux/io-pgtable.h> > +#include <linux/mm.h> > +#include <linux/mmu_context.h> > +#include <linux/mmu_notifier.h> > #include <linux/module.h> > #include <linux/of_iommu.h> > #include <linux/of_platform.h> > @@ -28,6 +31,7 @@ > #include <uapi/linux/virtio_iommu.h> > #include "iommu-pasid-table.h" > #include "iommu-sva-lib.h" > +#include "io-pgtable-arm.h"Is this used here?> > #define MSI_IOVA_BASE 0x8000000 > #define MSI_IOVA_LENGTH 0x100000 > @@ -41,6 +45,7 @@ DEFINE_XARRAY_ALLOC1(viommu_asid_xa); > > static DEFINE_MUTEX(sva_lock); > static DEFINE_MUTEX(iopf_lock); > +static DEFINE_MUTEX(viommu_asid_lock); > > struct viommu_dev_pri_work { > struct work_struct work; > @@ -88,10 +93,22 @@ struct viommu_mapping { > struct viommu_mm { > int pasid; > u64 archid; > + struct viommu_sva_bond *bond; > struct io_pgtable_ops *ops; > struct viommu_domain *domain; > }; > > +struct viommu_sva_bond { > + struct iommu_sva sva; > + struct mm_struct *mm; > + struct iommu_psdtable_mmu_notifier *viommu_mn; > + struct list_head list; > + refcount_t refs; > +}; > + > +#define sva_to_viommu_bond(handle) \ > + container_of(handle, struct viommu_sva_bond, sva) > + > struct viommu_domain { > struct iommu_domain domain; > struct viommu_dev *viommu; > @@ -136,6 +153,7 @@ struct viommu_endpoint { > bool pri_supported; > bool sva_enabled; > bool iopf_enabled; > + struct list_head bonds; > }; > > struct viommu_ep_entry { > @@ -1423,14 +1441,15 @@ static int viommu_attach_pasid_table(struct viommu_endpoint *vdev, > > pst_cfg->iommu_dev = viommu->dev->parent; > > + mutex_lock(&viommu_asid_lock); > /* Prepare PASID tables info to allocate a new table */ > ret = viommu_prepare_pst(vdev, pst_cfg, fmt); > if (ret) > - return ret; > + goto err_out_unlock; > > ret = iommu_psdtable_alloc(tbl, pst_cfg); > if (ret) > - return ret; > + goto err_out_unlock; > > pst_cfg->iommu_dev = viommu->dev->parent; > pst_cfg->fmt = PASID_TABLE_ARM_SMMU_V3; > @@ -1452,6 +1471,7 @@ static int viommu_attach_pasid_table(struct viommu_endpoint *vdev, > if (ret) > goto err_free_ops; > } > + mutex_unlock(&viommu_asid_lock); > } else { > /* TODO: otherwise, check for compatibility with vdev. */ > return -ENOSYS; > @@ -1467,6 +1487,8 @@ static int viommu_attach_pasid_table(struct viommu_endpoint *vdev, > err_free_psdtable: > iommu_psdtable_free(tbl, &tbl->cfg); > > +err_out_unlock: > + mutex_unlock(&viommu_asid_lock); > return ret; > } > > @@ -1706,6 +1728,7 @@ static struct iommu_device *viommu_probe_device(struct device *dev) > vdev->dev = dev; > vdev->viommu = viommu; > INIT_LIST_HEAD(&vdev->resv_regions); > + INIT_LIST_HEAD(&vdev->bonds); > dev_iommu_priv_set(dev, vdev); > > if (viommu->probe_size) { > @@ -1755,6 +1778,175 @@ static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) > return iommu_fwspec_add_ids(dev, args->args, 1); > } > > +static u32 viommu_sva_get_pasid(struct iommu_sva *handle) > +{ > + struct viommu_sva_bond *bond = sva_to_viommu_bond(handle); > + > + return bond->mm->pasid; > +} > + > +static void viommu_mmu_notifier_free(struct mmu_notifier *mn) > +{ > + kfree(mn_to_pstiommu(mn)); > +} > + > +static struct mmu_notifier_ops viommu_mmu_notifier_ops = { > + .free_notifier = viommu_mmu_notifier_free,.invalidate_range and .release will be needed as well, to keep up to date with changes to the address space> +}; > + > +/* Allocate or get existing MMU notifier for this {domain, mm} pair */ > +static struct iommu_psdtable_mmu_notifier * > +viommu_mmu_notifier_get(struct viommu_domain *vdomain, struct mm_struct *mm, > + u32 asid_bits) > +{ > + int ret; > + struct iommu_psdtable_mmu_notifier *viommu_mn; > + struct iommu_pasid_table *tbl = vdomain->pasid_tbl; > + > + list_for_each_entry(viommu_mn, &tbl->mmu_notifiers, list) { > + if (viommu_mn->mn.mm == mm) { > + refcount_inc(&viommu_mn->refs); > + return viommu_mn; > + } > + } > + > + mutex_lock(&viommu_asid_lock); > + viommu_mn = iommu_psdtable_alloc_shared(tbl, mm, &viommu_asid_xa, > + asid_bits); > + mutex_unlock(&viommu_asid_lock); > + if (IS_ERR(viommu_mn)) > + return ERR_CAST(viommu_mn); > + > + refcount_set(&viommu_mn->refs, 1); > + viommu_mn->cookie = vdomain; > + viommu_mn->mn.ops = &viommu_mmu_notifier_ops; > + > + ret = mmu_notifier_register(&viommu_mn->mn, mm); > + if (ret) > + goto err_free_cd; > + > + ret = iommu_psdtable_write(tbl, &tbl->cfg, mm->pasid, > + viommu_mn->vendor.cd); > + if (ret) > + goto err_put_notifier; > + > + list_add(&viommu_mn->list, &tbl->mmu_notifiers); > + return viommu_mn; > + > +err_put_notifier: > + /* Frees viommu_mn */ > + mmu_notifier_put(&viommu_mn->mn); > +err_free_cd: > + iommu_psdtable_free_shared(tbl, &viommu_asid_xa, viommu_mn->vendor.cd); > + return ERR_PTR(ret); > +} > + > +static void > +viommu_mmu_notifier_put(struct iommu_psdtable_mmu_notifier *viommu_mn) > +{ > + struct mm_struct *mm = viommu_mn->mn.mm; > + struct viommu_domain *vdomain = viommu_mn->cookie; > + struct iommu_pasid_table *tbl = vdomain->pasid_tbl; > + u16 asid = viommu_mn->vendor.cd->asid; > + > + if (!refcount_dec_and_test(&viommu_mn->refs)) > + return; > + > + list_del(&viommu_mn->list); > + iommu_psdtable_write(tbl, &tbl->cfg, mm->pasid, NULL); > + > + /* > + * If we went through clear(), we've already invalidated, and no > + * new TLB entry can have been formed. > + */ > + if (!viommu_mn->cleared) > + iommu_psdtable_flush_tlb(tbl, vdomain, asid); > + > + /* Frees smmu_mn */ > + mmu_notifier_put(&viommu_mn->mn); > + iommu_psdtable_free_shared(tbl, &viommu_asid_xa, viommu_mn->vendor.cd); > +} > + > +static struct iommu_sva * > +__viommu_sva_bind(struct device *dev, struct mm_struct *mm) > +{ > + int ret; > + struct viommu_sva_bond *bond; > + struct iommu_domain *domain = iommu_get_domain_for_dev(dev); > + struct viommu_domain *vdomain = to_viommu_domain(domain); > + struct viommu_endpoint *vdev = dev_iommu_priv_get(dev); > + struct virtio_iommu_probe_table_format *desc = vdev->pgtf; > + > + if (!vdev || !vdev->sva_enabled) > + return ERR_PTR(-ENODEV); > + > + /* If bind() was already called for this {dev, mm} pair, reuse it. */ > + list_for_each_entry(bond, &vdev->bonds, list) { > + if (bond->mm == mm) { > + refcount_inc(&bond->refs); > + return &bond->sva; > + } > + } > + > + bond = kzalloc(sizeof(*bond), GFP_KERNEL); > + if (!bond) > + return ERR_PTR(-ENOMEM); > + > + /* Allocate a PASID for this mm if necessary */ > + ret = iommu_sva_alloc_pasid(mm, 1, (1U << vdev->pasid_bits) - 1); > + if (ret) > + goto err_free_bond; > + > + bond->mm = mm; > + bond->sva.dev = dev; > + refcount_set(&bond->refs, 1); > + > + bond->viommu_mn = viommu_mmu_notifier_get(vdomain, mm, desc->asid_bits); > + if (IS_ERR(bond->viommu_mn)) { > + ret = PTR_ERR(bond->viommu_mn); > + goto err_free_pasid; > + } > + > + list_add(&bond->list, &vdev->bonds); > + return &bond->sva; > + > +err_free_pasid: > + iommu_sva_free_pasid(mm); > +err_free_bond: > + kfree(bond); > + return ERR_PTR(ret); > +} > + > +/* closely follows arm_smmu_sva_bind() */ > +static struct iommu_sva *viommu_sva_bind(struct device *dev, > + struct mm_struct *mm, void *drvdata) > +{ > + struct iommu_sva *handle; > + > + mutex_lock(&sva_lock); > + handle = __viommu_sva_bind(dev, mm); > + mutex_unlock(&sva_lock); > + return handle; > +} > + > +void viommu_sva_unbind(struct iommu_sva *handle) > +{ > + struct viommu_sva_bond *bond = sva_to_viommu_bond(handle); > + struct viommu_endpoint *vdev = dev_iommu_priv_get(handle->dev); > + > + if (vdev->pri_supported) > + iopf_queue_flush_dev(handle->dev); > + > + mutex_lock(&sva_lock); > + if (refcount_dec_and_test(&bond->refs)) { > + list_del(&bond->list); > + viommu_mmu_notifier_put(bond->viommu_mn); > + iommu_sva_free_pasid(bond->mm); > + kfree(bond); > + } > + mutex_unlock(&sva_lock); > +} > + > static bool viommu_endpoint_iopf_supported(struct viommu_endpoint *vdev) > { > /* TODO: support Stall model later */ > @@ -1960,6 +2152,9 @@ static struct iommu_ops viommu_ops = { > .dev_feat_enabled = viommu_dev_feature_enabled, > .dev_enable_feat = viommu_dev_enable_feature, > .dev_disable_feat = viommu_dev_disable_feature, > + .sva_bind = viommu_sva_bind, > + .sva_unbind = viommu_sva_unbind, > + .sva_get_pasid = viommu_sva_get_pasid, > }; > > static int viommu_init_vqs(struct viommu_dev *viommu) > diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h > index 88a3db493108..c12d9b6a7243 100644 > --- a/include/uapi/linux/virtio_iommu.h > +++ b/include/uapi/linux/virtio_iommu.h > @@ -122,6 +122,8 @@ struct virtio_iommu_req_attach_pst_arm { > #define VIRTIO_IOMMU_PGTF_ARM_HPD0 (1ULL << 41) > #define VIRTIO_IOMMU_PGTF_ARM_EPD1 (1 << 23) > > +#define VIRTIO_IOMMU_PGTF_ARM_IPS_SHIFT 32 > +#define VIRTIO_IOMMU_PGTF_ARM_IPS_MASK 0x7Probably not the right place for this change Thanks, Jean> #define VIRTIO_IOMMU_PGTF_ARM_TG0_SHIFT 14 > #define VIRTIO_IOMMU_PGTF_ARM_TG0_MASK 0x3 > #define VIRTIO_IOMMU_PGTF_ARM_SH0_SHIFT 12 > -- > 2.17.1 >