On Fri, Sep 14, 2018 at 12:54:57PM -0700, Stephen Hemminger wrote:
> Matching network device based on MAC address is problematic
> since a non VF network device can be creted with a duplicate MAC
> address causing confusion and problems. The VMBus API does provide
> a serial number that is a better matching method.
>
> Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
> ---
> drivers/net/hyperv/netvsc.c | 3 ++
> drivers/net/hyperv/netvsc_drv.c | 58 +++++++++++++++++++--------------
> 2 files changed, 36 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
> index 31c3d77b4733..fe01e141c8f8 100644
> --- a/drivers/net/hyperv/netvsc.c
> +++ b/drivers/net/hyperv/netvsc.c
> @@ -1203,6 +1203,9 @@ static void netvsc_send_vf(struct net_device *ndev,
>
> net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
> net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
> + netdev_info(ndev, "VF slot %u %s\n",
> + net_device_ctx->vf_serial,
> + net_device_ctx->vf_alloc ? "added" : "removed");
> }
>
> static void netvsc_receive_inband(struct net_device *ndev,
> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> index 1121a1ec407c..9dedc1463e88 100644
> --- a/drivers/net/hyperv/netvsc_drv.c
> +++ b/drivers/net/hyperv/netvsc_drv.c
> @@ -1894,20 +1894,6 @@ static void netvsc_link_change(struct work_struct *w)
> rtnl_unlock();
> }
>
> -static struct net_device *get_netvsc_bymac(const u8 *mac)
> -{
> - struct net_device_context *ndev_ctx;
> -
> - list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
> - struct net_device *dev = hv_get_drvdata(ndev_ctx->device_ctx);
> -
> - if (ether_addr_equal(mac, dev->perm_addr))
> - return dev;
> - }
> -
> - return NULL;
> -}
> -
> static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
> {
> struct net_device_context *net_device_ctx;
> @@ -2036,26 +2022,48 @@ static void netvsc_vf_setup(struct work_struct *w)
> rtnl_unlock();
> }
>
> +/* Find netvsc by VMBus serial number.
> + * The PCI hyperv controller records the serial number as the slot.
> + */
> +static struct net_device *get_netvsc_byslot(const struct net_device
> *vf_netdev)
> +{
> + struct device *parent = vf_netdev->dev.parent;
> + struct net_device_context *ndev_ctx;
> + struct pci_dev *pdev;
> +
> + if (!parent || !dev_is_pci(parent))
> + return NULL; /* not a PCI device */
> +
> + pdev = to_pci_dev(parent);
> + if (!pdev->slot) {
> + netdev_notice(vf_netdev, "no PCI slot information\n");
> + return NULL;
> + }
> +
> + list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
> + if (!ndev_ctx->vf_alloc)
> + continue;
> +
> + if (ndev_ctx->vf_serial == pdev->slot->number)
> + return hv_get_drvdata(ndev_ctx->device_ctx);
In patch 1, pdev->slot->number is set to:
PCI_SLOT(wslot_to_devfn(hpdev->desc.win_slot.slot))
so I assume vf_serial is initialized (I have no knowledge of VMBUS and
hyper-V internals) to that value, somehow.
I also do not know how the wslot stuff is handled but I assume 5 bits
(ie dev bits in devfn) are enough.
BTW, I have noticed this patch (and patch 1) are already in -next so I will
drop them from the PCI patch queue.
Lorenzo
> + }
> +
> + netdev_notice(vf_netdev,
> + "no netdev found for slot %u\n", pdev->slot->number);
> + return NULL;
> +}
> +
> static int netvsc_register_vf(struct net_device *vf_netdev)
> {
> - struct net_device *ndev;
> struct net_device_context *net_device_ctx;
> - struct device *pdev = vf_netdev->dev.parent;
> struct netvsc_device *netvsc_dev;
> + struct net_device *ndev;
> int ret;
>
> if (vf_netdev->addr_len != ETH_ALEN)
> return NOTIFY_DONE;
>
> - if (!pdev || !dev_is_pci(pdev) || dev_is_pf(pdev))
> - return NOTIFY_DONE;
> -
> - /*
> - * We will use the MAC address to locate the synthetic interface to
> - * associate with the VF interface. If we don't find a matching
> - * synthetic interface, move on.
> - */
> - ndev = get_netvsc_bymac(vf_netdev->perm_addr);
> + ndev = get_netvsc_byslot(vf_netdev);
> if (!ndev)
> return NOTIFY_DONE;
>
> --
> 2.18.0
>
