Commit ad69dd0b authored by Parav Pandit's avatar Parav Pandit Committed by Michael S. Tsirkin
Browse files

vdpa: Introduce query of device config layout 



Introduce a command to query a device config layout.

An example query of network vdpa device:

$ vdpa dev add name bar mgmtdev vdpasim_net

$ vdpa dev config show
bar: mac 00:35:09:19:48:05 link up link_announce false mtu 1500

$ vdpa dev config show -jp
{
    "config": {
        "bar": {
            "mac": "00:35:09:19:48:05",
            "link ": "up",
            "link_announce ": false,
            "mtu": 1500,
        }
    }
}

Signed-off-by: default avatarParav Pandit <parav@nvidia.com>
Signed-off-by: default avatarEli Cohen <elic@nvidia.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20211026175519.87795-3-parav@nvidia.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 6dbb1f16

drivers/vdpa/vdpa.c

+176 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 
#include <uapi/linux/vdpa.h>

#include <net/genetlink.h>

#include <linux/mod_devicetable.h>

#include <linux/virtio_net.h>

#include <linux/virtio_ids.h>



static LIST_HEAD(mdev_head);

/* A global mutex that protects vdpa management device and device level operations. */
@@ -66,6 +68,7 @@ static void vdpa_release_dev(struct device *d) 
		ops->free(vdev);



	ida_simple_remove(&vdpa_index_ida, vdev->index);

	mutex_destroy(&vdev->cf_mutex);

	kfree(vdev);

}
@@ -127,6 +130,7 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent, 
	if (err)

		goto err_name;



	mutex_init(&vdev->cf_mutex);

	device_initialize(&vdev->dev);



	return vdev;
@@ -309,6 +313,7 @@ void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset, 
{

	const struct vdpa_config_ops *ops = vdev->config;



	mutex_lock(&vdev->cf_mutex);

	/*

	 * Config accesses aren't supposed to trigger before features are set.

	 * If it does happen we assume a legacy guest.
@@ -316,6 +321,7 @@ void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset, 
	if (!vdev->features_valid)

		vdpa_set_features(vdev, 0);

	ops->get_config(vdev, offset, buf, len);

	mutex_unlock(&vdev->cf_mutex);

}

EXPORT_SYMBOL_GPL(vdpa_get_config);
@@ -329,7 +335,9 @@ EXPORT_SYMBOL_GPL(vdpa_get_config); 
void vdpa_set_config(struct vdpa_device *vdev, unsigned int offset,

		     const void *buf, unsigned int length)

{

	mutex_lock(&vdev->cf_mutex);

	vdev->config->set_config(vdev, offset, buf, length);

	mutex_unlock(&vdev->cf_mutex);

}

EXPORT_SYMBOL_GPL(vdpa_set_config);
@@ -661,6 +669,168 @@ static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callba 
	return msg->len;

}



static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,

				       struct sk_buff *msg, u64 features,

				       const struct virtio_net_config *config)

{

	u16 val_u16;



	if ((features & (1ULL << VIRTIO_NET_F_MQ)) == 0)

		return 0;



	val_u16 = le16_to_cpu(config->max_virtqueue_pairs);

	return nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, val_u16);

}



static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)

{

	struct virtio_net_config config = {};

	u64 features;

	u16 val_u16;



	vdpa_get_config(vdev, 0, &config, sizeof(config));



	if (nla_put(msg, VDPA_ATTR_DEV_NET_CFG_MACADDR, sizeof(config.mac),

		    config.mac))

		return -EMSGSIZE;



	val_u16 = le16_to_cpu(config.status);

	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16))

		return -EMSGSIZE;



	val_u16 = le16_to_cpu(config.mtu);

	if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16))

		return -EMSGSIZE;



	features = vdev->config->get_features(vdev);



	return vdpa_dev_net_mq_config_fill(vdev, msg, features, &config);

}



static int

vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,

		     int flags, struct netlink_ext_ack *extack)

{

	u32 device_id;

	void *hdr;

	int err;



	hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags,

			  VDPA_CMD_DEV_CONFIG_GET);

	if (!hdr)

		return -EMSGSIZE;



	if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) {

		err = -EMSGSIZE;

		goto msg_err;

	}



	device_id = vdev->config->get_device_id(vdev);

	if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id)) {

		err = -EMSGSIZE;

		goto msg_err;

	}



	switch (device_id) {

	case VIRTIO_ID_NET:

		err = vdpa_dev_net_config_fill(vdev, msg);

		break;

	default:

		err = -EOPNOTSUPP;

		break;

	}

	if (err)

		goto msg_err;



	genlmsg_end(msg, hdr);

	return 0;



msg_err:

	genlmsg_cancel(msg, hdr);

	return err;

}



static int vdpa_nl_cmd_dev_config_get_doit(struct sk_buff *skb, struct genl_info *info)

{

	struct vdpa_device *vdev;

	struct sk_buff *msg;

	const char *devname;

	struct device *dev;

	int err;



	if (!info->attrs[VDPA_ATTR_DEV_NAME])

		return -EINVAL;

	devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);

	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg)

		return -ENOMEM;



	mutex_lock(&vdpa_dev_mutex);

	dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match);

	if (!dev) {

		NL_SET_ERR_MSG_MOD(info->extack, "device not found");

		err = -ENODEV;

		goto dev_err;

	}

	vdev = container_of(dev, struct vdpa_device, dev);

	if (!vdev->mdev) {

		NL_SET_ERR_MSG_MOD(info->extack, "unmanaged vdpa device");

		err = -EINVAL;

		goto mdev_err;

	}

	err = vdpa_dev_config_fill(vdev, msg, info->snd_portid, info->snd_seq,

				   0, info->extack);

	if (!err)

		err = genlmsg_reply(msg, info);



mdev_err:

	put_device(dev);

dev_err:

	mutex_unlock(&vdpa_dev_mutex);

	if (err)

		nlmsg_free(msg);

	return err;

}



static int vdpa_dev_config_dump(struct device *dev, void *data)

{

	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);

	struct vdpa_dev_dump_info *info = data;

	int err;



	if (!vdev->mdev)

		return 0;

	if (info->idx < info->start_idx) {

		info->idx++;

		return 0;

	}

	err = vdpa_dev_config_fill(vdev, info->msg, NETLINK_CB(info->cb->skb).portid,

				   info->cb->nlh->nlmsg_seq, NLM_F_MULTI,

				   info->cb->extack);

	if (err)

		return err;



	info->idx++;

	return 0;

}



static int

vdpa_nl_cmd_dev_config_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)

{

	struct vdpa_dev_dump_info info;



	info.msg = msg;

	info.cb = cb;

	info.start_idx = cb->args[0];

	info.idx = 0;



	mutex_lock(&vdpa_dev_mutex);

	bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_config_dump);

	mutex_unlock(&vdpa_dev_mutex);

	cb->args[0] = info.idx;

	return msg->len;

}



static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {

	[VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING },

	[VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING },
@@ -692,6 +862,12 @@ static const struct genl_ops vdpa_nl_ops[] = { 
		.doit = vdpa_nl_cmd_dev_get_doit,

		.dumpit = vdpa_nl_cmd_dev_get_dumpit,

	},

	{

		.cmd = VDPA_CMD_DEV_CONFIG_GET,

		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

		.doit = vdpa_nl_cmd_dev_config_get_doit,

		.dumpit = vdpa_nl_cmd_dev_config_get_dumpit,

	},

};



static struct genl_family vdpa_nl_family __ro_after_init = {

include/linux/vdpa.h

+2 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ struct vdpa_mgmt_dev; 
 * @dev: underlying device

 * @dma_dev: the actual device that is performing DMA

 * @config: the configuration ops for this device.

 * @cf_mutex: Protects get and set access to configuration layout.

 * @index: device index

 * @features_valid: were features initialized? for legacy guests

 * @use_va: indicate whether virtual address must be used by this device
@@ -74,6 +75,7 @@ struct vdpa_device { 
	struct device dev;

	struct device *dma_dev;

	const struct vdpa_config_ops *config;

	struct mutex cf_mutex; /* Protects get/set config */

	unsigned int index;

	bool features_valid;

	bool use_va;

include/uapi/linux/vdpa.h

+6 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ enum vdpa_command { 
	VDPA_CMD_DEV_NEW,

	VDPA_CMD_DEV_DEL,

	VDPA_CMD_DEV_GET,		/* can dump */

	VDPA_CMD_DEV_CONFIG_GET,	/* can dump */

};



enum vdpa_attr {
@@ -34,6 +35,11 @@ enum vdpa_attr { 
	VDPA_ATTR_DEV_MAX_VQ_SIZE,		/* u16 */

	VDPA_ATTR_DEV_MIN_VQ_SIZE,		/* u16 */



	VDPA_ATTR_DEV_NET_CFG_MACADDR,		/* binary */

	VDPA_ATTR_DEV_NET_STATUS,		/* u8 */

	VDPA_ATTR_DEV_NET_CFG_MAX_VQP,		/* u16 */

	VDPA_ATTR_DEV_NET_CFG_MTU,		/* u16 */



	/* new attributes must be added above here */

	VDPA_ATTR_MAX,

};