The virtqueue group is the minimal set of virtqueues that must share an
address space. And the address space identifier could only be attached
to a specific virtqueue group. The virtqueue is attached to a
virtqueue group for all the life of the device.
During vDPA device allocation, the VDUSE device needs to report the
number of virtqueue groups supported. At this moment only vhost_vdpa is
able to do it.
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 we need to back the vq groups with a struct device for the file
operations, let's keep this number as low as possible at the moment: 2.
We can back one VQ group with the vduse device and the other one with
the vdpa device.
Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
---
drivers/vdpa/vdpa_user/vduse_dev.c | 44 +++++++++++++++++++++++++++++-
include/uapi/linux/vduse.h | 17 +++++++++++-
2 files changed, 59 insertions(+), 2 deletions(-)
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 6a9a37351310..6fa687bc4912 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -46,6 +46,11 @@
#define VDUSE_IOVA_SIZE (VDUSE_MAX_BOUNCE_SIZE + 128 * 1024 * 1024)
#define VDUSE_MSG_DEFAULT_TIMEOUT 30
+/*
+ * Let's make it 2 for simplicity.
+ */
+#define VDUSE_MAX_VQ_GROUPS 2
+
#define IRQ_UNBOUND -1
struct vduse_virtqueue {
@@ -114,6 +119,7 @@ struct vduse_dev {
u8 status;
u32 vq_num;
u32 vq_align;
+ u32 ngroups;
struct vduse_umem *umem;
struct mutex mem_lock;
unsigned int bounce_size;
@@ -592,6 +598,25 @@ static int vduse_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 idx,
return 0;
}
+static u32 vduse_get_vq_group(struct vdpa_device *vdpa, u16 idx)
+{
+ struct vduse_dev *dev = vdpa_to_vduse(vdpa);
+ struct vduse_dev_msg msg = { 0 };
+ int ret;
+
+ if (dev->api_version < VDUSE_API_VERSION_1)
+ return 0;
+
+ msg.req.type = VDUSE_GET_VQ_GROUP;
+ msg.req.vq_group.index = idx;
+
+ ret = vduse_dev_msg_sync(dev, &msg);
+ if (ret)
+ return ret;
+
+ return msg.resp.vq_group.num;
+}
+
static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx,
struct vdpa_vq_state *state)
{
@@ -789,6 +814,7 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
.set_vq_cb = vduse_vdpa_set_vq_cb,
.set_vq_num = vduse_vdpa_set_vq_num,
.get_vq_size = vduse_vdpa_get_vq_size,
+ .get_vq_group = vduse_get_vq_group,
.set_vq_ready = vduse_vdpa_set_vq_ready,
.get_vq_ready = vduse_vdpa_get_vq_ready,
.set_vq_state = vduse_vdpa_set_vq_state,
@@ -1850,6 +1876,16 @@ static int vduse_create_dev(struct vduse_dev_config *config,
dev->device_features = config->features;
dev->device_id = config->device_id;
dev->vendor_id = config->vendor_id;
+ if (dev->api_version >= 1) {
+ if (config->ngroups > VDUSE_MAX_VQ_GROUPS) {
+ pr_err("Not creating a VDUSE device with %u vq groups. Max: %u",
+ config->ngroups, VDUSE_MAX_VQ_GROUPS);
+ goto err_ngroups;
+ }
+ dev->ngroups = config->ngroups ?: 1;
+ } else {
+ dev->ngroups = 1;
+ }
dev->name = kstrdup(config->name, GFP_KERNEL);
if (!dev->name)
goto err_str;
@@ -1885,6 +1921,7 @@ static int vduse_create_dev(struct vduse_dev_config *config,
idr_remove(&vduse_idr, dev->minor);
err_idr:
kfree(dev->name);
+err_ngroups:
err_str:
vduse_dev_destroy(dev);
err:
@@ -2003,13 +2040,18 @@ static struct vduse_mgmt_dev *vduse_mgmt;
static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
{
struct vduse_vdpa *vdev;
+ __u32 ngroups = 1;
int ret;
if (dev->vdev)
return -EEXIST;
+ if (vdev->dev->api_version >= VDUSE_API_VERSION_1)
+ ngroups = vdev->dev->ngroups;
+
vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev,
- &vduse_vdpa_config_ops, 1, 1, name, true);
+ &vduse_vdpa_config_ops, ngroups, 1, name,
+ true);
if (IS_ERR(vdev))
return PTR_ERR(vdev);
diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
index 9a56d0416bfe..a779bcddac58 100644
--- a/include/uapi/linux/vduse.h
+++ b/include/uapi/linux/vduse.h
@@ -45,7 +45,8 @@ struct vduse_dev_config {
__u64 features;
__u32 vq_num;
__u32 vq_align;
- __u32 reserved[13];
+ __u32 ngroups; /* if VDUSE_API_VERSION >= 1 */
+ __u32 reserved[12];
__u32 config_size;
__u8 config[];
};
@@ -160,6 +161,16 @@ struct vduse_vq_state_packed {
__u16 last_used_idx;
};
+/**
+ * struct vduse_vq_group - virtqueue group
+ * @num: Index of the virtqueue group
+ * @num: Group
+ */
+struct vduse_vq_group {
+ __u32 index;
+ __u32 num;
+};
+
/**
* struct vduse_vq_info - information of a virtqueue
* @index: virtqueue index
@@ -182,6 +193,7 @@ struct vduse_vq_info {
union {
struct vduse_vq_state_split split;
struct vduse_vq_state_packed packed;
+ struct vduse_vq_group group;
};
__u8 ready;
};
@@ -274,6 +286,7 @@ enum vduse_req_type {
VDUSE_GET_VQ_STATE,
VDUSE_SET_STATUS,
VDUSE_UPDATE_IOTLB,
+ VDUSE_GET_VQ_GROUP,
};
/**
@@ -328,6 +341,7 @@ struct vduse_dev_request {
struct vduse_vq_state vq_state;
struct vduse_dev_status s;
struct vduse_iova_range iova;
+ struct vduse_vq_group vq_group; /* Only if vduse api version >= 1 */
__u32 padding[32];
};
};
@@ -350,6 +364,7 @@ struct vduse_dev_response {
__u32 reserved[4];
union {
struct vduse_vq_state vq_state;
+ struct vduse_vq_group vq_group; /* Only if vduse api version >= 1 */
__u32 padding[32];
};
};
--
2.49.0
