This patch converts the vhost-vDPA device to support multiple IOTLBs
tagged via ASID via hlist. This will be used for supporting multiple
address spaces in the following patches.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Gautam Dawar <redacted>
---
 drivers/vhost/vdpa.c | 104 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 79 insertions(+), 25 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index d0aacc0cc79a..4e8b7c4809cd 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c

@@ -33,13 +33,21 @@ enum {

 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)

+#define VHOST_VDPA_IOTLB_BUCKETS 16
+
+struct vhost_vdpa_as {
+       struct hlist_node hash_link;
+       struct vhost_iotlb iotlb;
+       u32 id;
+};
+
 struct vhost_vdpa {
        struct vhost_dev vdev;
        struct iommu_domain *domain;
        struct vhost_virtqueue *vqs;
        struct completion completion;
        struct vdpa_device *vdpa;
-       struct vhost_iotlb *iotlb;
+       struct hlist_head as[VHOST_VDPA_IOTLB_BUCKETS];
        struct device dev;
        struct cdev cdev;
        atomic_t opened;

@@ -49,12 +57,64 @@ struct vhost_vdpa {
        struct eventfd_ctx *config_ctx;
        int in_batch;
        struct vdpa_iova_range range;
+       int used_as;

+
+       if (!as)
+               return -EINVAL;
+
+       hlist_del(&as->hash_link);
+       vhost_iotlb_reset(&as->iotlb);
+       kfree(as);
+       --v->used_as;
+
+       return 0;
+}
+
 static void handle_vq_kick(struct vhost_work *work)
 {
        struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,

@@ -554,15 +614,6 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v,
        return vhost_vdpa_pa_unmap(v, iotlb, start, last);
 }

-static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
-{
-       struct vhost_iotlb *iotlb = v->iotlb;
-
-       vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1);
-       kfree(v->iotlb);
-       v->iotlb = NULL;
-}
-
 static int perm_to_iommu_flags(u32 perm)
 {
        int flags = 0;

@@ -842,7 +893,8 @@ 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_iotlb *iotlb = v->iotlb;
+       struct vhost_vdpa_as *as = asid_to_as(v, 0);
+       struct vhost_iotlb *iotlb = &as->iotlb;
        int r = 0;

        mutex_lock(&dev->mutex);

@@ -953,6 +1005,13 @@ static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
        }
 }

+static void vhost_vdpa_cleanup(struct vhost_vdpa *v)
+{
+       vhost_dev_cleanup(&v->vdev);
+       kfree(v->vdev.vqs);
+       vhost_vdpa_remove_as(v, 0);
+}
+
 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
 {
        struct vhost_vdpa *v;

@@ -985,15 +1044,12 @@ 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);

-       v->iotlb = vhost_iotlb_alloc(0, 0);
-       if (!v->iotlb) {
-               r = -ENOMEM;
-               goto err_init_iotlb;
-       }
+       if (!vhost_vdpa_alloc_as(v, 0))
+               goto err_alloc_as;

        r = vhost_vdpa_alloc_domain(v);
        if (r)
-               goto err_alloc_domain;
+               goto err_alloc_as;

        vhost_vdpa_set_iova_range(v);

@@ -1001,11 +1057,8 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)

        return 0;

-err_alloc_domain:
-       vhost_vdpa_iotlb_free(v);
-err_init_iotlb:
-       vhost_dev_cleanup(&v->vdev);
-       kfree(vqs);
+err_alloc_as:
+       vhost_vdpa_cleanup(v);
 err:
        atomic_dec(&v->opened);
        return r;

@@ -1029,11 +1082,9 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
        vhost_vdpa_clean_irq(v);
        vhost_vdpa_reset(v);
        vhost_dev_stop(&v->vdev);
-       vhost_vdpa_iotlb_free(v);
        vhost_vdpa_free_domain(v);
        vhost_vdpa_config_put(v);
        vhost_dev_cleanup(&v->vdev);
-       kfree(v->vdev.vqs);
        mutex_unlock(&d->mutex);

        atomic_dec(&v->opened);

@@ -1129,7 +1180,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
        const struct vdpa_config_ops *ops = vdpa->config;
        struct vhost_vdpa *v;
        int minor;
-       int r;
+       int i, r;

        /* Only support 1 address space and 1 groups */
        if (vdpa->ngroups != 1 || vdpa->nas != 1)

@@ -1177,6 +1228,9 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
        init_completion(&v->completion);
        vdpa_set_drvdata(vdpa, v);

+       for (i = 0; i < VHOST_VDPA_IOTLB_BUCKETS; i++)
+               INIT_HLIST_HEAD(&v->as[i]);
+
        return 0;

 err:
--

2.25.0