runefivm: Allow multiple tap interfaces

Allow multiple interfaces by passing them as a colon-separated
list in the NETIF variable: NETIF="tap0:tap1"

Signed-off-by: Marc Zyngier <maz@kernel.org>

2 files changed, 52 insertions, 36 deletions

diff --git a/README b/README
index f18e4b2..3658dbb 100644
--- a/README
+++ b/README
@@ -45,7 +45,9 @@ at some point. Maybe.
   - NETIF: The host network interface for this VM. Can be a tap or
     macvtap interface (which enables vhost), or "none" (which
     indicates that no networking is to be provided). When absent,
-    userspace networking is provided to the guest.
+    userspace networking is provided to the guest. Multiple taps
+    can be passed as a colon separated list, each of them resulting
+    in a guest network interface.
 
   - GIC: The GIC version. Use "2" to force GICv2, "3" for GICv3+ITS,
     "3,noits" for GICv3 without an ITS. Defaults to "host", which is
diff --git a/runefivm.sh b/runefivm.sh
index a67179b..6525b37 100755
--- a/runefivm.sh
+++ b/runefivm.sh
@@ -16,6 +16,49 @@ cputype=${CPUTYPE-host}
 dumpdtb=${DUMPDTB}
 withdtb=${WITHDTB}
 
+nifidx=0
+tapfd=128
+tapredir=""
+vhredir=""
+netdev=""
+
+build_netdev()
+{
+    nif=$1
+    if [ -e /dev/tap$(< /sys/class/net/$nif/ifindex) ]; then
+	addr=$(< /sys/class/net/$nif/address)
+	tap=/dev/tap$(< /sys/class/net/$nif/ifindex)
+	mq=$((`ls -1 /sys/class/net/$nif/queues/ | wc -l ` / 2))
+
+	tapfds="$(($tapfd))"
+	tapredir+="$(($tapfd))<>$tap "
+	vhfds="$(($tapfd+$mq))"
+	vhredir+="$(($tapfd+$mq))<>/dev/vhost-net "
+
+	for i in `seq 1 $(($mq-1))`
+	do
+	    tapfds+=":$((i+$tapfd))"
+	    tapredir+="$((i+$tapfd))<>$tap "
+	    vhfds+=":$((i+$tapfd+$mq))"
+	    vhredir+="$((i+$tapfd+$mq))<>/dev/vhost-net "
+	done
+
+	netdev+="-netdev tap,fds=$tapfds,id=hostnet$nifidx,vhost=on,vhostfds=$vhfds \
+		-device virtio-net-$bus$virtio,mac=$addr,netdev=hostnet$nifidx,mq=on,vectors=$((2*$mq+2)) "
+
+    else
+	mq=$((`ls -1 /sys/class/net/$nif/queues/ | wc -l ` / 2))
+	mq=4
+	vectors="mq=on,vectors=$((2*$mq+2))"
+	suffix=`echo $disk | md5sum | sed -e 's/^\(..\)\(..\)\(..\)\(.*\)/\1:\2:\3/'`
+	netdev="-netdev tap,vhost=on,queues=$mq,id=hostnet$nifidx,ifname=$nif,script=no,downscript=no \
+		-device virtio-net-$bus$virtio,netdev=hostnet$nifidx,mac=5a:fe:00:$suffix,$vectors"
+    fi
+
+    tapfd=$(($tapfd + $mq + 1))
+    nifidx=$(($nifidx + 1))
+}
+
 if [ "$bit" = 64 ]; then
 	sf=on
 else
@@ -49,43 +92,14 @@ if [ "$disk" != none ]; then
 fi
 
 if [ "$netif" == none ]; then
-
-        netdev="-net none"
-
+    netdev="-net none"
 elif [ -z "$netif" -o $bus != pci ]; then
-
-	netdev="-netdev user,id=hostnet0 -device virtio-net-$bus$virtio,netdev=hostnet0"
-
-elif [ -e /dev/tap$(< /sys/class/net/$netif/ifindex) ]; then
-
-	addr=$(< /sys/class/net/$netif/address)
-	tap=/dev/tap$(< /sys/class/net/$netif/ifindex)
-	mq=$((`ls -1 /sys/class/net/$netif/queues/ | wc -l ` / 2))
-	tapfd=128
-
-	tapfds="$(($tapfd))"
-	tapredir="$(($tapfd))<>$tap"
-	vhfds="$(($tapfd+$mq))"
-	vhredir="$(($tapfd+$mq))<>/dev/vhost-net"
-
-	for i in `seq 1 $(($mq-1))`
-	do
-		tapfds+=":$((i+$tapfd))"
-		tapredir+=" $((i+$tapfd))<>$tap"
-		vhfds+=":$((i+$tapfd+$mq))"
-		vhredir+=" $((i+$tapfd+$mq))<>/dev/vhost-net"
-	done
-
-	netdev="-netdev tap,fds=$tapfds,id=hostnet0,vhost=on,vhostfds=$vhfds \
-		-device virtio-net-$bus$virtio,mac=$addr,netdev=hostnet0,mq=on,vectors=$((2*$mq+2))"
-
+    netdev="-netdev user,id=hostnet0 -device virtio-net-$bus$virtio,netdev=hostnet0"
 else
-	mq=$((`ls -1 /sys/class/net/$netif/queues/ | wc -l ` / 2))
-	mq=4
-	vectors="mq=on,vectors=$((2*$mq+2))"
-	suffix=`echo $disk | md5sum | sed -e 's/^\(..\)\(..\)\(..\)\(.*\)/\1:\2:\3/'`
-	netdev="-netdev tap,vhost=on,queues=$mq,id=hostnet0,ifname=$netif,script=no,downscript=no \
-		-device virtio-net-$bus$virtio,netdev=hostnet0,mac=5a:fe:00:$suffix,$vectors"
+    IFS=':' read -ra nifs <<< "$netif"
+    for i in "${nifs[@]}"; do
+	build_netdev $i
+    done
 fi
 
 args="  -m $ram -smp $cpus -cpu $cputype,aarch64=$sf -machine virt,accel=$accel,gic-version=$gic \