> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Linhaifeng > Sent: Sunday, January 25, 2015 12:42 PM > To: Loftus, Ciara; dev at dpdk.org > Cc: Anthony Fee > Subject: Re: [dpdk-dev] [PATCH v2] vhost: add interface name to virtio-net > struct > > > > On 2014/12/19 2:07, ciara.loftus at intel.com wrote: > > From: Ciara Loftus <ciara.loftus at intel.com> > > > > This patch fixes the issue whereby when using userspace vhost ports > > in the context of vSwitching, the name provided to the hypervisor/QEMU > > of the vhost tap device needs to be exposed in the library, in order > > Who create the tap device?When using vhost-user QEMU will not create it. > > > for the vSwitch to be able to direct packets to the correct device. > > Why not use unix domain socket path?
In this patch, for vhost-cuse, the ifname comes from the name of the tap device. For vhost-user, ifname is the name of the socket path. > > > This patch introduces an 'ifname' member to the virtio-net structure > > which is populated with the tap device name when QEMU is brought up > > with a vhost device. > > > > Signed-off-by: Ciara Loftus <ciara.loftus at intel.com> > > Signed-off-by: Anthony Fee <anthonyx.fee at intel.com> > > Acked-by: Huawei Xie <huawei.xie at intel.com> > > --- > > lib/librte_vhost/rte_virtio_net.h | 3 ++ > > lib/librte_vhost/virtio-net.c | 48 > ++++++++++++++++++++++++++++++++++++- > > 2 files changed, 50 insertions(+), 1 deletions(-) > > > > diff --git a/lib/librte_vhost/rte_virtio_net.h > > b/lib/librte_vhost/rte_virtio_net.h > > index 00b1328..0bf07c7 100644 > > --- a/lib/librte_vhost/rte_virtio_net.h > > +++ b/lib/librte_vhost/rte_virtio_net.h > > @@ -43,6 +43,8 @@ > > #include <linux/virtio_ring.h> > > #include <linux/virtio_net.h> > > #include <sys/eventfd.h> > > +#include <sys/socket.h> > > +#include <linux/if.h> > > > > #include <rte_memory.h> > > #include <rte_mempool.h> > > @@ -96,6 +98,7 @@ struct virtio_net { > > uint64_t features; /**< Negotiated feature set. > */ > > uint64_t device_fh; /**< device identifier. */ > > uint32_t flags; /**< Device flags. Only used to > check if device is running on data core. */ > > + char ifname[IFNAMSIZ]; /**< Name of the tap > device. */ > > void *priv; /**< private context */ > > } __rte_cache_aligned; > > > > diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c > > index 852b6d1..7eae5ee 100644 > > --- a/lib/librte_vhost/virtio-net.c > > +++ b/lib/librte_vhost/virtio-net.c > > @@ -43,6 +43,10 @@ > > #include <sys/mman.h> > > #include <unistd.h> > > > > +#include <sys/socket.h> > > +#include <linux/if_tun.h> > > +#include <linux/if.h> > > + > > #include <rte_ethdev.h> > > #include <rte_log.h> > > #include <rte_string_fns.h> > > @@ -1000,6 +1004,46 @@ set_vring_kick(struct vhost_device_ctx ctx, struct > vhost_vring_file *file) > > } > > > > /* > > + * Function to get the tap device name from the provided file descriptor > > and > > + * save it in the device structure. > > + */ > > +static int > > +get_ifname(struct virtio_net *dev, int tap_fd, int pid) > > +{ > > + struct eventfd_copy fd_tap; > > + struct ifreq ifr; > > + uint32_t size, ifr_size; > > + int ret; > > + > > + fd_tap.source_fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); > > + fd_tap.target_fd = tap_fd; > > + fd_tap.target_pid = pid; > > + > > + if (eventfd_copy(dev, &fd_tap)) > > + return -1; > > + > > + ret = ioctl(fd_tap.source_fd, TUNGETIFF, &ifr); > > + > > + if (close(fd_tap.source_fd) < 0) > > + RTE_LOG(ERR, VHOST_CONFIG, > > + "(%"PRIu64") fd close failed\n", > > + dev->device_fh); > > + > > + if (ret >= 0) { > > + ifr_size = strnlen(ifr.ifr_name, sizeof(ifr.ifr_name)); > > + size = ifr_size > sizeof(dev->ifname)? > > + sizeof(dev->ifname): ifr_size; > > + > > + strncpy(dev->ifname, ifr.ifr_name, size); > > + } else > > + RTE_LOG(ERR, VHOST_CONFIG, > > + "(%"PRIu64") TUNGETIFF ioctl failed\n", > > + dev->device_fh); > > + > > + return 0; > > +} > > + > > +/* > > * Called from CUSE IOCTL: VHOST_NET_SET_BACKEND > > * To complete device initialisation when the virtio driver is loaded, > > * we are provided with a valid fd for a tap device (not used by us). > > @@ -1026,8 +1070,10 @@ set_backend(struct vhost_device_ctx ctx, struct > vhost_vring_file *file) > > */ > > if (!(dev->flags & VIRTIO_DEV_RUNNING)) { > > if (((int)dev->virtqueue[VIRTIO_TXQ]->backend != > VIRTIO_DEV_STOPPED) && > > - ((int)dev->virtqueue[VIRTIO_RXQ]->backend != > VIRTIO_DEV_STOPPED)) > > + ((int)dev->virtqueue[VIRTIO_RXQ]->backend != > VIRTIO_DEV_STOPPED)) { > > + get_ifname(dev, file->fd, ctx.pid); > > return notify_ops->new_device(dev); > > + } > > /* Otherwise we remove it. */ > > } else > > if (file->fd == VIRTIO_DEV_STOPPED) > > > > -- > Regards, > Haifeng