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Commit 40c9db8a authored by Thomas Falcon's avatar Thomas Falcon Committed by David S. Miller
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ibmvnic: Client-initiated failover 



The IBM vNIC protocol provides support for the user to initiate
a failover from the client LPAR in case the current backing infrastructure
is deemed inadequate or in an error state.

Support for two H_VIOCTL sub-commands for vNIC devices are required
to implement this function. These commands are H_GET_SESSION_TOKEN
and H_SESSION_ERR_DETECTED.

"[H_GET_SESSION_TOKEN] is used to obtain a session token from a VNIC client
adapter.  This token is opaque to the caller and is intended to be used in
tandem with the SESSION_ERROR_DETECTED vioctl subfunction."

"[H_SESSION_ERR_DETECTED] is used to report that the currently active
backing device for a VNIC client adapter is behaving poorly, and that
the hypervisor should attempt to fail over to a different backing device,
if one is available."

To provide tools access to this functionality the vNIC driver creates a
sysfs file that, when written to, will send a request to pHyp to failover
to a different backing device.

Signed-off-by: default avatarThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Reviewed-by: default avatarNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 725757ae

arch/powerpc/include/asm/hvcall.h

+2 −0
Original line number Diff line number Diff line
@@ -295,6 +295,8 @@ 
#define H_DISABLE_ALL_VIO_INTS	0x0A

#define H_DISABLE_VIO_INTERRUPT	0x0B

#define H_ENABLE_VIO_INTERRUPT	0x0C

#define H_GET_SESSION_TOKEN	0x19

#define H_SESSION_ERR_DETECTED	0x1A





/* Platform specific hcalls, used by KVM */

drivers/net/ethernet/ibm/ibmvnic.c

+46 −0
Original line number Diff line number Diff line
@@ -3656,6 +3656,8 @@ static int ibmvnic_init(struct ibmvnic_adapter *adapter) 
	return rc;

}



static struct device_attribute dev_attr_failover;



static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)

{

	struct ibmvnic_adapter *adapter;
@@ -3712,9 +3714,16 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id) 


	netdev->mtu = adapter->req_mtu - ETH_HLEN;



	rc = device_create_file(&dev->dev, &dev_attr_failover);

	if (rc) {

		free_netdev(netdev);

		return rc;

	}



	rc = register_netdev(netdev);

	if (rc) {

		dev_err(&dev->dev, "failed to register netdev rc=%d\n", rc);

		device_remove_file(&dev->dev, &dev_attr_failover);

		free_netdev(netdev);

		return rc;

	}
@@ -3740,12 +3749,49 @@ static int ibmvnic_remove(struct vio_dev *dev) 
	adapter->state = VNIC_REMOVED;



	mutex_unlock(&adapter->reset_lock);

	device_remove_file(&dev->dev, &dev_attr_failover);

	free_netdev(netdev);

	dev_set_drvdata(&dev->dev, NULL);



	return 0;

}



static ssize_t failover_store(struct device *dev, struct device_attribute *attr,

			      const char *buf, size_t count)

{

	struct net_device *netdev = dev_get_drvdata(dev);

	struct ibmvnic_adapter *adapter = netdev_priv(netdev);

	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];

	__be64 session_token;

	long rc;



	if (!sysfs_streq(buf, "1"))

		return -EINVAL;



	rc = plpar_hcall(H_VIOCTL, retbuf, adapter->vdev->unit_address,

			 H_GET_SESSION_TOKEN, 0, 0, 0);

	if (rc) {

		netdev_err(netdev, "Couldn't retrieve session token, rc %ld\n",

			   rc);

		return -EINVAL;

	}



	session_token = (__be64)retbuf[0];

	netdev_dbg(netdev, "Initiating client failover, session id %llx\n",

		   be64_to_cpu(session_token));

	rc = plpar_hcall_norets(H_VIOCTL, adapter->vdev->unit_address,

				H_SESSION_ERR_DETECTED, session_token, 0, 0);

	if (rc) {

		netdev_err(netdev, "Client initiated failover failed, rc %ld\n",

			   rc);

		return -EINVAL;

	}



	return count;

}



static DEVICE_ATTR(failover, 0200, NULL, failover_store);



static unsigned long ibmvnic_get_desired_dma(struct vio_dev *vdev)

{

	struct net_device *netdev = dev_get_drvdata(&vdev->dev);