Jason Wang
2022-May-07 10:24 UTC
[PATCH v2 15/19] vhost-vdpa: support ASID based IOTLB API
On Thu, Apr 28, 2022 at 2:28 PM Gautam Dawar <gdawar at xilinx.com> wrote:> > -----Original Message----- > From: Jason Wang <jasowang at redhat.com> > Sent: Friday, April 1, 2022 9:55 AM > To: Gautam Dawar <gdawar at xilinx.com> > Cc: Michael S. Tsirkin <mst at redhat.com>; kvm <kvm at vger.kernel.org>; virtualization <virtualization at lists.linux-foundation.org>; netdev <netdev at vger.kernel.org>; linux-kernel <linux-kernel at vger.kernel.org>; Martin Petrus Hubertus Habets <martinh at xilinx.com>; Harpreet Singh Anand <hanand at xilinx.com>; Martin Porter <martinpo at xilinx.com>; Pablo Cascon <pabloc at xilinx.com>; Dinan Gunawardena <dinang at xilinx.com>; tanuj.kamde at amd.com; habetsm.xilinx at gmail.com; ecree.xilinx at gmail.com; eperezma <eperezma at redhat.com>; Gautam Dawar <gdawar at xilinx.com>; Wu Zongyong <wuzongyong at linux.alibaba.com>; Christophe JAILLET <christophe.jaillet at wanadoo.fr>; Eli Cohen <elic at nvidia.com>; Zhu Lingshan <lingshan.zhu at intel.com>; Stefano Garzarella <sgarzare at redhat.com>; Xie Yongji <xieyongji at bytedance.com>; Si-Wei Liu <si-wei.liu at oracle.com>; Parav Pandit <parav at nvidia.com>; Longpeng <longpeng2 at huawei.com>; Dan Carpenter <dan.carpenter at oracle.com>; Zhang Min <zhang.min9 at zte.com.cn> > Subject: Re: [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. > [GD>>] Isn?t the following check in vhost_vdpa_alloc_as () sufficient to ensure ASID's value in the range [0, dev->nas): > if (asid >= v->vdpa->nas) > return NULL;I think you're right. So we are fine. Thanks> > 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 > > >