mlx5_vdpa does not preserve userland's view of vring base for the control
queue in the following sequence:
ioctl VHOST_SET_VRING_BASE
ioctl VHOST_VDPA_SET_STATUS VIRTIO_CONFIG_S_DRIVER_OK
mlx5_vdpa_set_status()
setup_cvq_vring()
vringh_init_iotlb()
vringh_init_kern()
vrh->last_avail_idx = 0;
ioctl VHOST_GET_VRING_BASE
To fix, restore the value of cvq->vring.last_avail_idx after calling
vringh_init_iotlb.
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
drivers/vdpa/mlx5/net/mlx5_vnet.c | 7 ++++++-
drivers/vhost/vringh.c | 30 ++++++++++++++++++++++++++++++
include/linux/vringh.h | 2 ++
3 files changed, 38 insertions(+), 1 deletion(-)
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 946488b8989f..f64758143115 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -2795,13 +2795,18 @@ static int setup_cvq_vring(struct mlx5_vdpa_dev *mvdev)
struct mlx5_control_vq *cvq = &mvdev->cvq;
int err = 0;
- if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ))
+ if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)) {
+ u16 last_avail_idx = cvq->vring.last_avail_idx;
+
err = vringh_init_iotlb(&cvq->vring, mvdev->actual_features,
MLX5_CVQ_MAX_ENT, false,
(struct vring_desc
*)(uintptr_t)cvq->desc_addr,
(struct vring_avail
*)(uintptr_t)cvq->driver_addr,
(struct vring_used
*)(uintptr_t)cvq->device_addr);
+ if (!err)
+ vringh_set_base_iotlb(&cvq->vring, last_avail_idx);
+ }
return err;
}
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 7b8fd977f71c..799762c83007 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -595,6 +595,24 @@ static inline void __vringh_notify_disable(struct vringh
*vrh,
}
}
+static inline int __vringh_set_base(struct vringh *vrh, u16 idx,
+ int (*putu16)(const struct vringh *vrh,
+ __virtio16 *p, u16 val))
+{
+ int ret;
+
+ ret = putu16(vrh, &vrh->vring.avail->idx, idx);
+ if (ret)
+ return ret;
+
+ ret = putu16(vrh, &vrh->vring.used->idx, idx);
+ if (ret)
+ return ret;
+
+ vrh->last_avail_idx = vrh->last_used_idx = idx;
+ return 0;
+}
+
/* Userspace access helpers: in this case, addresses are really userspace. */
static inline int getu16_user(const struct vringh *vrh, u16 *val, const
__virtio16 *p)
{
@@ -1456,6 +1474,18 @@ void vringh_set_iotlb(struct vringh *vrh, struct
vhost_iotlb *iotlb,
}
EXPORT_SYMBOL(vringh_set_iotlb);
+/**
+ * vringh_set_base_iotlb - set avail_idx and used_idx
+ * @vrh: the vring
+ * @idx: the value to set
+ */
+int vringh_set_base_iotlb(struct vringh *vrh, u16 idx)
+{
+ return __vringh_set_base(vrh, idx, putu16_iotlb);
+}
+EXPORT_SYMBOL(vringh_set_base_iotlb);
+
+
/**
* vringh_getdesc_iotlb - get next available descriptor from ring with
* IOTLB.
diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index c3a8117dabe8..e9b8af4e6a5e 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -306,6 +306,8 @@ int vringh_init_iotlb_va(struct vringh *vrh, u64 features,
struct vring_avail *avail,
struct vring_used *used);
+int vringh_set_base_iotlb(struct vringh *vrh, u16 idx);
+
int vringh_getdesc_iotlb(struct vringh *vrh,
struct vringh_kiov *riov,
struct vringh_kiov *wiov,
--
2.39.3
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