On 06/12/2017 12:35 PM, Thomas Falcon wrote:
> 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: Thomas Falcon <tlfal...@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nf...@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/hvcall.h | 2 ++
> drivers/net/ethernet/ibm/ibmvnic.c | 46
> ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 48 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/hvcall.h
> b/arch/powerpc/include/asm/hvcall.h
> index d73755f..57d38b5 100644
> --- a/arch/powerpc/include/asm/hvcall.h
> +++ b/arch/powerpc/include/asm/hvcall.h
> @@ -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 */
> diff --git a/drivers/net/ethernet/ibm/ibmvnic.c
> b/drivers/net/ethernet/ibm/ibmvnic.c
> index 7d84e20..fd3ef30 100644
> --- a/drivers/net/ethernet/ibm/ibmvnic.c
> +++ b/drivers/net/ethernet/ibm/ibmvnic.c
> @@ -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);
>
