Create tap interface ourselves

Since we no longer run the ifup script, we need to add a parameter for mtu,
which could be abused for other 'ip link' setups... Don't really want an eval here.
This also allows to run qemu as user without much work.

5 files changed, 25 insertions, 42 deletions

diff --git a/kvm-wrapper.conf.default b/kvm-wrapper.conf.default
index 9dfadb4..ecd43fc 100644
--- a/kvm-wrapper.conf.default
+++ b/kvm-wrapper.conf.default
@@ -55,7 +55,8 @@ KVM_MACADDR[0]="`random_mac`"
 KVM_BR[0]="br0"
 KVM_NET_OPT[0]=""
 #KVM_NET_OPT[0]=",vhost=on"
-#KVM_{IF,MACADDR,BR,NET_OPT}[n]
+#KVM_NET_MTU[0]="9000"
+#KVM_{IF,MACADDR,BR,NET_OPT,NET_MTU}[n]
 
 KVM_BOOTDEVICE="-boot order=c"
 #KVM_DISK[0]
@@ -70,6 +71,9 @@ KVM_DISK_OPT[0]=",cache=none,aio=native"
 #KVM_VFIO_DOMAIN[0] # 01:00.0
 #KVM_VFIO_ID[0]     # "fooidname" (id string, no comma/whitespace/equalsign)
 
+# Setting user requires access to: /dev/kvm, /dev/net/tun,
+# /dev/vhost-net, /dev/vfio/vfio and ulimit -l big
+#KVM_USER="qemu"
 KVM_KEYMAP=""
 #KVM_KEYMAP="-k en-us"
 KVM_OUTPUT="-curses"
diff --git a/kvm-wrapper.sh b/kvm-wrapper.sh
index e830220..3198ab5 100755
--- a/kvm-wrapper.sh
+++ b/kvm-wrapper.sh
@@ -391,6 +391,12 @@ function pci_unstubify()
 function pci_vfiofy()
 {
 	pci_bind_driver "vfio-pci" "$1"
+
+	if [[ -n "$KVM_USER" ]]; then
+		local IOMMU_GROUP=$(readlink "/sys/bus/pci/drivers/vfio-pci/$1/iommu_group")
+		IOMMU_GROUP=${IOMMU_GROUP##*/}
+		chown $KVM_USER: /dev/vfio/$IOMMU_GROUP
+	fi
 }
 
 function pci_unvfiofy()
@@ -398,7 +404,7 @@ function pci_unvfiofy()
 	pci_unbind_driver "vfio-pci" "$1"
 }
 
-# helper for vfio
+# helper for sriov
 function ib_sriov()
 {
 	local PKEYS="$1"
@@ -661,16 +667,7 @@ function kvm_start_vm ()
 	}
 	[[ "${KVM_IF[0]}" = "vhost_net" ]] && (KVM_NET_OPT[0]=",vhost=on"; KVM_IF[0]="virtio-net-pci")
 
-	# Check for the bridge-specific symlinks an' make them otherwise (no quotes on $KVM_BR* because it would otherwise try to create kvm--ifup)
-	for BR in "${KVM_BR[@]}"; do
-		test_exist "$KVM_NET_SCRIPT/kvm-$BR-ifup" || \
-			(cd "$KVM_NET_SCRIPT"; ln -s kvm-ifup "kvm-$BR-ifup")
-		test_exist "$KVM_NET_SCRIPT/kvm-$BR-ifdown" || \
-			(cd "$KVM_NET_SCRIPT"; ln -s kvm-ifdown "kvm-$BR-ifdown")
-	done
-
-
-	# Iterately build kvmnet string
+	# Iterately build kvmnet string and create tuntaps
 	[[ "${#KVM_MACADDR[@]}" != 0 ]] && {
 		# not checking KVM_NET_OPT because it _can_ be empty... others will raise an error
 		[[ -z "${KVM_BR[@]:0:1}" ]] && fail_exit "No KVM_BR defined"
@@ -679,7 +676,13 @@ function kvm_start_vm ()
 			KVM_BR[$i]="${KVM_BR[i]:-${KVM_BR[@]:0:1}}"
 			KVM_IF[$i]="${KVM_IF[i]:-${KVM_IF[@]:0:1}}"
 			KVM_NET_OPT[$i]="${KVM_NET_OPT[i]-${KVM_NET_OPT[@]:0:1}}"
-			KVM_NET+="-netdev type=tap,id=guest${i},script=$KVM_NET_SCRIPT/kvm-${KVM_BR[i]}-ifup,downscript=$KVM_NET_SCRIPT/kvm-${KVM_BR[i]}-ifdown${KVM_NET_OPT[i]} -device ${KVM_IF[i]},netdev=guest${i},mac=${KVM_MACADDR[i]} "
+			KVM_NET_MTU[$i]="${KVM_NET_MTU[i]-${KVM_NET_MTU[@]:0:1}}"
+			local TAPDEV=tap-${VM_NAME}-${i}
+			KVM_NET+="-netdev type=tap,id=guest${i},ifname=${TAPDEV},script=no,downscript=no${KVM_NET_OPT[i]} -device ${KVM_IF[i]},netdev=guest${i},mac=${KVM_MACADDR[i]} "
+			ip tuntap add dev $TAPDEV mode tap ${KVM_USER+user $KVM_USER}
+			ip link set $TAPDEV ${KVM_NET_MTU[$i]:+mtu ${KVM_NET_MTU[$i]}} up
+			brctl addif ${KVM_BR[i]} $TAPDEV
+			CLEANUP+=("ip tuntap del dev $TAPDEV mode tap")
 		done
 	}
 
@@ -716,7 +719,11 @@ function kvm_start_vm ()
 	echo $EXEC_STRING
 	echo ""
 	echo ""
-	eval "$EXEC_STRING"
+	if [[ -n "$KVM_USER" ]]; then
+		su $KVM_USER -s /bin/sh -c "$EXEC_STRING"
+	else
+		eval "$EXEC_STRING"
+	fi
 
 	local KVM_RETURN_VALUE="$?"
 
diff --git a/net/.gitignore b/net/.gitignore
deleted file mode 100644
index 7970659..0000000
--- a/net/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-kvm-*-ifup
-kvm-*-ifdown
\ No newline at end of file
diff --git a/net/kvm-ifdown b/net/kvm-ifdown
deleted file mode 100755
index d72e728..0000000
--- a/net/kvm-ifdown
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/bin/sh
-#
-# Script called by kvm on tap interface deletion
-#
-
-KVM_BR=`basename $0 -ifdown|sed -e 's/^[^-]*-\?//'`
-KVM_BRIDGE=${KVM_BR:-$KVM_BRIDGE}
-
-echo "$0:"
-echo "Removing $1 from bridge $KVM_BRIDGE"
-ip link set "$1" down
-brctl delif "$KVM_BRIDGE" "$1"
-
diff --git a/net/kvm-ifup b/net/kvm-ifup
deleted file mode 100755
index 9e425e6..0000000
--- a/net/kvm-ifup
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/bin/sh
-#
-# Script called by kvm on tap interface creation
-#
-
-KVM_BR=`basename $0 -ifup|sed -e 's/^[^-]*-\?//'`
-KVM_BRIDGE=${KVM_BR:-$KVM_BRIDGE}
-
-echo "$0:"
-echo "Adding $1 to bridge interface $KVM_BRIDGE"
-brctl addif "$KVM_BRIDGE" "$1"
-ip link set "$1" up
-