From a7c36ee4920ea3acc227a0248dd161693f207357 Mon Sep 17 00:00:00 2001 From: Corey Bryant Date: Thu, 26 Jan 2012 09:42:27 -0500 Subject: Add support for net bridge The most common use of -net tap is to connect a tap device to a bridge. This requires the use of a script and running qemu as root in order to allocate a tap device to pass to the script. This model is great for portability and flexibility but it's incredibly difficult to eliminate the need to run qemu as root. The only really viable mechanism is to use tunctl to create a tap device, attach it to a bridge as root, and then hand that tap device to qemu. The problem with this mechanism is that it requires administrator intervention whenever a user wants to create a guest. By essentially writing a helper that implements the most common qemu-ifup script that can be safely given cap_net_admin, we can dramatically simplify things for non-privileged users. We still support existing -net tap options as a mechanism for advanced users and backwards compatibility. Currently, this is very Linux centric but there's really no reason why it couldn't be extended for other Unixes. A typical invocation would be similar to one of the following: qemu linux.img -net bridge -net nic,model=virtio qemu linux.img -net tap,helper="/usr/local/libexec/qemu-bridge-helper" -net nic,model=virtio qemu linux.img -netdev bridge,id=hn0 -device virtio-net-pci,netdev=hn0,id=nic1 qemu linux.img -netdev tap,helper="/usr/local/libexec/qemu-bridge-helper",id=hn0 -device virtio-net-pci,netdev=hn0,id=nic1 The default bridge that we attach to is br0. The thinking is that a distro could preconfigure such an interface to allow out-of-the-box bridged networking. Alternatively, if a user wants to use a different bridge, a typical invocation would be simliar to one of the following: qemu linux.img -net bridge,br=qemubr0 -net nic,model=virtio qemu linux.img -net tap,helper="/usr/local/libexec/qemu-bridge-helper --br=qemubr0" -net nic,model=virtio qemu linux.img -netdev bridge,br=qemubr0,id=hn0 -device virtio-net-pci,netdev=hn0,id=nic1 qemu linux.img -netdev tap,helper="/usr/local/libexec/qemu-bridge-helper --br=qemubr0",id=hn0 -device virtio-net-pci,netdev=hn0,id=nic1 Signed-off-by: Anthony Liguori Signed-off-by: Richa Marwaha Signed-off-by: Corey Bryant Signed-off-by: Anthony Liguori --- configure | 2 ++ 1 file changed, 2 insertions(+) (limited to 'configure') diff --git a/configure b/configure index 9f2a7e1..763db24 100755 --- a/configure +++ b/configure @@ -2942,6 +2942,8 @@ echo "sysconfdir=$sysconfdir" >> $config_host_mak echo "docdir=$docdir" >> $config_host_mak echo "confdir=$confdir" >> $config_host_mak echo "libexecdir=\${prefix}/libexec" >> $config_host_mak +echo "CONFIG_QEMU_SHAREDIR=\"$prefix$datasuffix\"" >> $config_host_mak +echo "CONFIG_QEMU_HELPERDIR=\"$prefix/libexec\"" >> $config_host_mak echo "ARCH=$ARCH" >> $config_host_mak if test "$debug_tcg" = "yes" ; then -- cgit v1.1