[PATCH 07/21] vdpa: multiple address spaces support

From: Jason Wang
Date: Wed Dec 16 2020 - 01:51:15 EST


This patches introduces the multiple address spaces support for vDPA
device. This idea is to identify a specific address space via an
dedicated identifier - ASID.

During vDPA device allocation, vDPA device driver needs to report the
number of address spaces supported by the device then the DMA mapping
ops of the vDPA device needs to be extended to support ASID.

This helps to isolate the environments for the virtqueue that will not
be assigned directly. E.g in the case of virtio-net, the control
virtqueue will not be assigned directly to guest.

As a start, simply claim 1 virtqueue groups and 1 address spaces for
all vDPA devices. And vhost-vDPA will simply reject the device with
more than 1 virtqueue groups or address spaces.

Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/vdpa/ifcvf/ifcvf_main.c | 2 +-
drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +++--
drivers/vdpa/vdpa.c | 4 +++-
drivers/vdpa/vdpa_sim/vdpa_sim.c | 10 ++++++----
drivers/vhost/vdpa.c | 14 +++++++++-----
include/linux/vdpa.h | 23 ++++++++++++++++-------
6 files changed, 38 insertions(+), 20 deletions(-)

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index c629f4fcc738..8a43f562b169 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -445,7 +445,7 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)

adapter = vdpa_alloc_device(struct ifcvf_adapter, vdpa,
dev, &ifc_vdpa_ops,
- IFCVF_MAX_QUEUE_PAIRS * 2, 1);
+ IFCVF_MAX_QUEUE_PAIRS * 2, 1, 1);

if (adapter == NULL) {
IFCVF_ERR(pdev, "Failed to allocate vDPA structure");
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 719b52fcc547..7aaf0a4ee80d 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1804,7 +1804,8 @@ static u32 mlx5_vdpa_get_generation(struct vdpa_device *vdev)
return mvdev->generation;
}

-static int mlx5_vdpa_set_map(struct vdpa_device *vdev, struct vhost_iotlb *iotlb)
+static int mlx5_vdpa_set_map(struct vdpa_device *vdev, unsigned int asid,
+ struct vhost_iotlb *iotlb)
{
struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
@@ -1947,7 +1948,7 @@ void *mlx5_vdpa_add_dev(struct mlx5_core_dev *mdev)
max_vqs = min_t(u32, max_vqs, MLX5_MAX_SUPPORTED_VQS);

ndev = vdpa_alloc_device(struct mlx5_vdpa_net, mvdev.vdev, mdev->device, &mlx5_vdpa_ops,
- 2 * mlx5_vdpa_max_qps(max_vqs), 1);
+ 2 * mlx5_vdpa_max_qps(max_vqs), 1, 1);
if (IS_ERR(ndev))
return ndev;

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 46399746ec7c..05195fa7865d 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -63,6 +63,7 @@ static void vdpa_release_dev(struct device *d)
* @config: the bus operations that is supported by this device
* @nvqs: number of virtqueues supported by this device
* @ngroups: number of groups supported by this device
+ * @nas: number of address spaces supported by this device
* @size: size of the parent structure that contains private data
*
* Driver should use vdpa_alloc_device() wrapper macro instead of
@@ -74,7 +75,7 @@ static void vdpa_release_dev(struct device *d)
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
const struct vdpa_config_ops *config,
int nvqs, unsigned int ngroups,
- size_t size)
+ unsigned int nas, size_t size)
{
struct vdpa_device *vdev;
int err = -EINVAL;
@@ -102,6 +103,7 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
vdev->features_valid = false;
vdev->nvqs = nvqs;
vdev->ngroups = ngroups;
+ vdev->nas = nas;

err = dev_set_name(&vdev->dev, "vdpa%u", vdev->index);
if (err)
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 5d554b3cd152..140de45ffff2 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -359,7 +359,7 @@ static struct vdpasim *vdpasim_create(void)
ops = &vdpasim_net_config_ops;

vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
- VDPASIM_VQ_NUM, 1);
+ VDPASIM_VQ_NUM, 1, 1);
if (!vdpasim)
goto err_alloc;

@@ -606,7 +606,7 @@ static struct vdpa_iova_range vdpasim_get_iova_range(struct vdpa_device *vdpa)
return range;
}

-static int vdpasim_set_map(struct vdpa_device *vdpa,
+static int vdpasim_set_map(struct vdpa_device *vdpa, unsigned int asid,
struct vhost_iotlb *iotlb)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
@@ -633,7 +633,8 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
return ret;
}

-static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
+static int vdpasim_dma_map(struct vdpa_device *vdpa, unsigned int asid,
+ u64 iova, u64 size,
u64 pa, u32 perm)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
@@ -647,7 +648,8 @@ static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
return ret;
}

-static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size)
+static int vdpasim_dma_unmap(struct vdpa_device *vdpa, unsigned int asid,
+ u64 iova, u64 size)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 9bcc03d4e68b..03a9b3311c6c 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -570,10 +570,10 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
return r;

if (ops->dma_map) {
- r = ops->dma_map(vdpa, iova, size, pa, perm);
+ r = ops->dma_map(vdpa, 0, iova, size, pa, perm);
} else if (ops->set_map) {
if (!v->in_batch)
- r = ops->set_map(vdpa, iotlb);
+ r = ops->set_map(vdpa, 0, iotlb);
} else {
r = iommu_map(v->domain, iova, pa, size,
perm_to_iommu_flags(perm));
@@ -597,10 +597,10 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v,
vhost_vdpa_iotlb_unmap(v, iotlb, iova, iova + size - 1);

if (ops->dma_map) {
- ops->dma_unmap(vdpa, iova, size);
+ ops->dma_unmap(vdpa, 0, iova, size);
} else if (ops->set_map) {
if (!v->in_batch)
- ops->set_map(vdpa, iotlb);
+ ops->set_map(vdpa, 0, iotlb);
} else {
iommu_unmap(v->domain, iova, size);
}
@@ -764,7 +764,7 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
break;
case VHOST_IOTLB_BATCH_END:
if (v->in_batch && ops->set_map)
- ops->set_map(vdpa, iotlb);
+ ops->set_map(vdpa, 0, iotlb);
v->in_batch = false;
break;
default:
@@ -1032,6 +1032,10 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
int minor;
int r;

+ /* Only support 1 address space and 1 groups */
+ if (vdpa->ngroups != 1 || vdpa->nas != 1)
+ return -ENOTSUPP;
+
/* Currently, we only accept the network devices. */
if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
return -ENOTSUPP;
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index bfc6790b263e..0a9a754f8180 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -43,6 +43,8 @@ struct vdpa_vq_state {
* @index: device index
* @features_valid: were features initialized? for legacy guests
* @nvqs: the number of virtqueues
+ * @ngroups: the number of virtqueue groups
+ * @nas: the number of address spaces
*/
struct vdpa_device {
struct device dev;
@@ -52,6 +54,7 @@ struct vdpa_device {
bool features_valid;
int nvqs;
unsigned int ngroups;
+ unsigned int nas;
};

/**
@@ -175,6 +178,7 @@ struct vdpa_iova_range {
* Needed for device that using device
* specific DMA translation (on-chip IOMMU)
* @vdev: vdpa device
+ * @asid: address space identifier
* @iotlb: vhost memory mapping to be
* used by the vDPA
* Returns integer: success (0) or error (< 0)
@@ -183,6 +187,7 @@ struct vdpa_iova_range {
* specific DMA translation (on-chip IOMMU)
* and preferring incremental map.
* @vdev: vdpa device
+ * @asid: address space identifier
* @iova: iova to be mapped
* @size: size of the area
* @pa: physical address for the map
@@ -194,6 +199,7 @@ struct vdpa_iova_range {
* specific DMA translation (on-chip IOMMU)
* and preferring incremental unmap.
* @vdev: vdpa device
+ * @asid: address space identifier
* @iova: iova to be unmapped
* @size: size of the area
* Returns integer: success (0) or error (< 0)
@@ -240,10 +246,12 @@ struct vdpa_config_ops {
struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);

/* DMA ops */
- int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
- int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
- u64 pa, u32 perm);
- int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
+ int (*set_map)(struct vdpa_device *vdev, unsigned int asid,
+ struct vhost_iotlb *iotlb);
+ int (*dma_map)(struct vdpa_device *vdev, unsigned int asid,
+ u64 iova, u64 size, u64 pa, u32 perm);
+ int (*dma_unmap)(struct vdpa_device *vdev, unsigned int asid,
+ u64 iova, u64 size);

/* Free device resources */
void (*free)(struct vdpa_device *vdev);
@@ -252,11 +260,12 @@ struct vdpa_config_ops {
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
const struct vdpa_config_ops *config,
int nvqs, unsigned int ngroups,
- size_t size);
+ unsigned int nas, size_t size);

-#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs, ngroups) \
+#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs, \
+ ngroups, nas) \
container_of(__vdpa_alloc_device( \
- parent, config, nvqs, ngroups, \
+ parent, config, nvqs, ngroups, nas, \
sizeof(dev_struct) + \
BUILD_BUG_ON_ZERO(offsetof( \
dev_struct, member))), \
--
2.25.1