Jason Wang
2022-Apr-01 04:24 UTC
[PATCH v2 15/19] vhost-vdpa: support ASID based IOTLB API
On Thu, Mar 31, 2022 at 2:17 AM Gautam Dawar <gautam.dawar at xilinx.com> wrote:> > This patch extends the vhost-vdpa to support ASID based IOTLB API. The > vhost-vdpa device will allocated multiple IOTLBs for vDPA device that > supports multiple address spaces. The IOTLBs and vDPA device memory > mappings is determined and maintained through ASID. > > Note that we still don't support vDPA device with more than one > address spaces that depends on platform IOMMU. This work will be done > by moving the IOMMU logic from vhost-vDPA to vDPA device driver. > > Signed-off-by: Jason Wang <jasowang at redhat.com> > Signed-off-by: Gautam Dawar <gdawar at xilinx.com> > --- > drivers/vhost/vdpa.c | 109 ++++++++++++++++++++++++++++++++++-------- > drivers/vhost/vhost.c | 2 +- > 2 files changed, 91 insertions(+), 20 deletions(-) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 6c7ee0f18892..1f1d1c425573 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -28,7 +28,8 @@ > enum { > VHOST_VDPA_BACKEND_FEATURES > (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) | > - (1ULL << VHOST_BACKEND_F_IOTLB_BATCH), > + (1ULL << VHOST_BACKEND_F_IOTLB_BATCH) | > + (1ULL << VHOST_BACKEND_F_IOTLB_ASID), > }; > > #define VHOST_VDPA_DEV_MAX (1U << MINORBITS) > @@ -57,12 +58,20 @@ struct vhost_vdpa { > struct eventfd_ctx *config_ctx; > int in_batch; > struct vdpa_iova_range range; > + u32 batch_asid; > }; > > static DEFINE_IDA(vhost_vdpa_ida); > > static dev_t vhost_vdpa_major; > > +static inline u32 iotlb_to_asid(struct vhost_iotlb *iotlb) > +{ > + struct vhost_vdpa_as *as = container_of(iotlb, struct > + vhost_vdpa_as, iotlb); > + return as->id; > +} > + > static struct vhost_vdpa_as *asid_to_as(struct vhost_vdpa *v, u32 asid) > { > struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS]; > @@ -75,6 +84,16 @@ static struct vhost_vdpa_as *asid_to_as(struct vhost_vdpa *v, u32 asid) > return NULL; > } > > +static struct vhost_iotlb *asid_to_iotlb(struct vhost_vdpa *v, u32 asid) > +{ > + struct vhost_vdpa_as *as = asid_to_as(v, asid); > + > + if (!as) > + return NULL; > + > + return &as->iotlb; > +} > + > static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid) > { > struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS]; > @@ -83,6 +102,9 @@ static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid) > if (asid_to_as(v, asid)) > return NULL; > > + if (asid >= v->vdpa->nas) > + return NULL; > + > as = kmalloc(sizeof(*as), GFP_KERNEL); > if (!as) > return NULL; > @@ -94,6 +116,17 @@ static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid) > return as; > } > > +static struct vhost_vdpa_as *vhost_vdpa_find_alloc_as(struct vhost_vdpa *v, > + u32 asid) > +{ > + struct vhost_vdpa_as *as = asid_to_as(v, asid); > + > + if (as) > + return as; > + > + return vhost_vdpa_alloc_as(v, asid); > +} > + > static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid) > { > struct vhost_vdpa_as *as = asid_to_as(v, asid); > @@ -692,6 +725,7 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb, > struct vhost_dev *dev = &v->vdev; > struct vdpa_device *vdpa = v->vdpa; > const struct vdpa_config_ops *ops = vdpa->config; > + u32 asid = iotlb_to_asid(iotlb); > int r = 0; > > r = vhost_iotlb_add_range_ctx(iotlb, iova, iova + size - 1, > @@ -700,10 +734,10 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb, > return r; > > if (ops->dma_map) { > - r = ops->dma_map(vdpa, 0, iova, size, pa, perm, opaque); > + r = ops->dma_map(vdpa, asid, iova, size, pa, perm, opaque); > } else if (ops->set_map) { > if (!v->in_batch) > - r = ops->set_map(vdpa, 0, iotlb); > + r = ops->set_map(vdpa, asid, iotlb); > } else { > r = iommu_map(v->domain, iova, pa, size, > perm_to_iommu_flags(perm)); > @@ -725,17 +759,24 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, > { > struct vdpa_device *vdpa = v->vdpa; > const struct vdpa_config_ops *ops = vdpa->config; > + u32 asid = iotlb_to_asid(iotlb); > > vhost_vdpa_iotlb_unmap(v, iotlb, iova, iova + size - 1); > > if (ops->dma_map) { > - ops->dma_unmap(vdpa, 0, iova, size); > + ops->dma_unmap(vdpa, asid, iova, size); > } else if (ops->set_map) { > if (!v->in_batch) > - ops->set_map(vdpa, 0, iotlb); > + ops->set_map(vdpa, asid, iotlb); > } else { > iommu_unmap(v->domain, iova, size); > } > + > + /* If we are in the middle of batch processing, delay the free > + * of AS until BATCH_END. > + */ > + if (!v->in_batch && !iotlb->nmaps) > + vhost_vdpa_remove_as(v, asid); > } > > static int vhost_vdpa_va_map(struct vhost_vdpa *v, > @@ -943,19 +984,38 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid, > struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev); > struct vdpa_device *vdpa = v->vdpa; > const struct vdpa_config_ops *ops = vdpa->config; > - struct vhost_vdpa_as *as = asid_to_as(v, 0); > - struct vhost_iotlb *iotlb = &as->iotlb; > + struct vhost_iotlb *iotlb = NULL; > + struct vhost_vdpa_as *as = NULL; > int r = 0; > > - if (asid != 0) > - return -EINVAL; > - > mutex_lock(&dev->mutex); > > r = vhost_dev_check_owner(dev); > if (r) > goto unlock; > > + if (msg->type == VHOST_IOTLB_UPDATE || > + msg->type == VHOST_IOTLB_BATCH_BEGIN) { > + as = vhost_vdpa_find_alloc_as(v, asid);I wonder if it's better to mandate the ASID to [0, dev->nas), otherwise user space is free to use arbitrary IDs which may exceeds the #address spaces that is supported by the device. Thanks> + if (!as) { > + dev_err(&v->dev, "can't find and alloc asid %d\n", > + asid); > + return -EINVAL; > + } > + iotlb = &as->iotlb; > + } else > + iotlb = asid_to_iotlb(v, asid); > + > + if ((v->in_batch && v->batch_asid != asid) || !iotlb) { > + if (v->in_batch && v->batch_asid != asid) { > + dev_info(&v->dev, "batch id %d asid %d\n", > + v->batch_asid, asid); > + } > + if (!iotlb) > + dev_err(&v->dev, "no iotlb for asid %d\n", asid); > + return -EINVAL; > + } > + > switch (msg->type) { > case VHOST_IOTLB_UPDATE: > r = vhost_vdpa_process_iotlb_update(v, iotlb, msg); > @@ -964,12 +1024,15 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid, > vhost_vdpa_unmap(v, iotlb, msg->iova, msg->size); > break; > case VHOST_IOTLB_BATCH_BEGIN: > + v->batch_asid = asid; > v->in_batch = true; > break; > case VHOST_IOTLB_BATCH_END: > if (v->in_batch && ops->set_map) > - ops->set_map(vdpa, 0, iotlb); > + ops->set_map(vdpa, asid, iotlb); > v->in_batch = false; > + if (!iotlb->nmaps) > + vhost_vdpa_remove_as(v, asid); > break; > default: > r = -EINVAL; > @@ -1057,9 +1120,17 @@ static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v) > > static void vhost_vdpa_cleanup(struct vhost_vdpa *v) > { > + struct vhost_vdpa_as *as; > + u32 asid; > + > vhost_dev_cleanup(&v->vdev); > kfree(v->vdev.vqs); > - vhost_vdpa_remove_as(v, 0); > + > + for (asid = 0; asid < v->vdpa->nas; asid++) { > + as = asid_to_as(v, asid); > + if (as) > + vhost_vdpa_remove_as(v, asid); > + } > } > > static int vhost_vdpa_open(struct inode *inode, struct file *filep) > @@ -1095,12 +1166,9 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep) > vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false, > vhost_vdpa_process_iotlb_msg); > > - if (!vhost_vdpa_alloc_as(v, 0)) > - goto err_alloc_as; > - > r = vhost_vdpa_alloc_domain(v); > if (r) > - goto err_alloc_as; > + goto err_alloc_domain; > > vhost_vdpa_set_iova_range(v); > > @@ -1108,7 +1176,7 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep) > > return 0; > > -err_alloc_as: > +err_alloc_domain: > vhost_vdpa_cleanup(v); > err: > atomic_dec(&v->opened); > @@ -1233,8 +1301,11 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa) > int minor; > int i, r; > > - /* Only support 1 address space and 1 groups */ > - if (vdpa->ngroups != 1 || vdpa->nas != 1) > + /* We can't support platform IOMMU device with more than 1 > + * group or as > + */ > + if (!ops->set_map && !ops->dma_map && > + (vdpa->ngroups > 1 || vdpa->nas > 1)) > return -EOPNOTSUPP; > > v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL); > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index d1e58f976f6e..5022c648d9c0 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -1167,7 +1167,7 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev, > ret = -EINVAL; > goto done; > } > - offset = sizeof(__u16); > + offset = 0; > } else > offset = sizeof(__u32); > break; > -- > 2.30.1 >