host/rootfs: switch VMs to templated s6 services

Now that VMMs and vhost-user devices are started immediately, we don't
need the complexity of s6-rc for them any more.  VMMs still depend on
the vhost-user sockets, but since those will be available almost
immediately, it's fine to just wait for them in ext-rc-init.

Since we're now using pure s6, we can use s6 instanced services for
these, which cuts down a lot on how much work ext-rc-init's up script
has to do directly, and provides some nice namespacing.

Signed-off-by: Alyssa Ross <hi@alyssa.is>

35 files changed, 118 insertions, 71 deletions

diff --git a/host/rootfs/Makefile b/host/rootfs/Makefile
index fc61c09..c5e467d 100644
--- a/host/rootfs/Makefile
+++ b/host/rootfs/Makefile
@@ -23,25 +23,55 @@ FILES = \
 	etc/s6-linux-init/run-image/service/getty-tty3/run \
 	etc/s6-linux-init/run-image/service/getty-tty4/run \
 	etc/s6-linux-init/run-image/service/getty-ttyS0/run \
+	etc/s6-linux-init/run-image/service/vhost-user-fs/notification-fd \
+	etc/s6-linux-init/run-image/service/vhost-user-fs/run \
+	etc/s6-linux-init/run-image/service/vhost-user-fs/template/notification-fd \
+	etc/s6-linux-init/run-image/service/vhost-user-fs/template/run \
+	etc/s6-linux-init/run-image/service/vhost-user-gpu/notification-fd \
+	etc/s6-linux-init/run-image/service/vhost-user-gpu/run \
+	etc/s6-linux-init/run-image/service/vhost-user-gpu/template/data/check \
+	etc/s6-linux-init/run-image/service/vhost-user-gpu/template/notification-fd \
+	etc/s6-linux-init/run-image/service/vhost-user-gpu/template/run \
+	etc/s6-linux-init/run-image/service/vmm/notification-fd \
+	etc/s6-linux-init/run-image/service/vmm/run \
+	etc/s6-linux-init/run-image/service/vmm/template/notification-fd \
 	etc/s6-linux-init/scripts/rc.init \
-	etc/template/fs/notification-fd \
-	etc/template/fs/run \
-	etc/template/fs/type \
-	etc/template/gpu/data/check \
-	etc/template/gpu/notification-fd \
-	etc/template/gpu/run \
-	etc/template/gpu/type \
+	etc/shared-dir \
 	etc/xdg/weston/autolaunch \
 	etc/xdg/weston/weston.ini \
 	usr/bin/lsvm \
 	usr/bin/vm-console \
 	usr/bin/vm-start \
 	usr/bin/vm-stop
-DIRS = dev etc/s6-linux-init/env etc/s6-linux-init/run-image/vm ext run proc sys
+
+DIRS = \
+	dev \
+	etc/s6-linux-init/env \
+	etc/s6-linux-init/run-image/service/vhost-user-fs/instance \
+	etc/s6-linux-init/run-image/service/vhost-user-fs/instances \
+	etc/s6-linux-init/run-image/service/vhost-user-fs/template/data \
+	etc/s6-linux-init/run-image/service/vhost-user-fs/template/env \
+	etc/s6-linux-init/run-image/service/vhost-user-gpu/instance \
+	etc/s6-linux-init/run-image/service/vhost-user-gpu/instances \
+	etc/s6-linux-init/run-image/service/vhost-user-gpu/template/env \
+	etc/s6-linux-init/run-image/service/vmm/instance \
+	etc/s6-linux-init/run-image/service/vmm/instances \
+	etc/s6-linux-init/run-image/service/vmm/template/data \
+	etc/s6-linux-init/run-image/service/vmm/template/env \
+	etc/s6-linux-init/run-image/vm \
+	ext \
+	run \
+	proc \
+	sys
 
 # These are separate because they need to be included, but putting
 # them as make dependencies would confuse make.
-LINKS = bin etc/s6-linux-init/run-image/opengl-driver lib sbin
+LINKS = \
+	bin \
+	etc/s6-linux-init/run-image/opengl-driver \
+	etc/s6-linux-init/run-image/service/vmm/template/run \
+	lib \
+	sbin
 
 BUILD_FILES = build/etc/mdev/modalias.sh build/etc/s6-rc
 
diff --git a/host/rootfs/etc/mdev/net/add b/host/rootfs/etc/mdev/net/add
index 64d126c..52ccacf 100755
--- a/host/rootfs/etc/mdev/net/add
+++ b/host/rootfs/etc/mdev/net/add
@@ -31,8 +31,8 @@ foreground {
 background {
   # Wait for the VM to be up.
   foreground { s6-rc -bu change ext-rc-init }
-  if { s6-svwait -U /run/service/ext-vm-netvm }
+  if { s6-svwait -U /run/service/vmm/instance/netvm }
 
-  ch-remote --api-socket /run/service/ext-vm-netvm/env/cloud-hypervisor.sock
+  ch-remote --api-socket /run/service/vmm/instance/netvm/env/cloud-hypervisor.sock
     add-device path=/sys${devpath}
 }
diff --git a/host/rootfs/etc/template/fs/notification-fd b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/notification-fd
index 00750ed..00750ed 100644
--- a/host/rootfs/etc/template/fs/notification-fd
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/notification-fd
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/notification-fd.license b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/notification-fd.license
new file mode 100644
index 0000000..a941ca4
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/notification-fd.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/run b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/run
new file mode 100755
index 0000000..9041788
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/run
@@ -0,0 +1,5 @@
+#!/bin/execlineb -P
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
+
+s6-svscan -d3 instance
diff --git a/host/rootfs/etc/template/gpu/notification-fd b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/template/notification-fd
index 00750ed..00750ed 100644
--- a/host/rootfs/etc/template/gpu/notification-fd
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/template/notification-fd
diff --git a/host/rootfs/etc/template/fs/notification-fd.license b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/template/notification-fd.license
index 5a40633..5a40633 100644
--- a/host/rootfs/etc/template/fs/notification-fd.license
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/template/notification-fd.license
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/template/run b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/template/run
new file mode 100755
index 0000000..c055cc0
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-fs/template/run
@@ -0,0 +1,12 @@
+#!/bin/execlineb -S1
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2021-2023 Alyssa Ross <hi@alyssa.is>
+
+s6-ipcserver-socketbinder -a 0700 -B env/virtiofsd.sock
+
+if { fdmove 1 3 echo }
+fdclose 3
+
+export TMPDIR /run
+backtick -E shared_dir { /etc/shared-dir -v servicename=${1} }
+virtiofsd --fd 0 --shared-dir $shared_dir
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/notification-fd b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/notification-fd
new file mode 100644
index 0000000..00750ed
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/notification-fd
@@ -0,0 +1 @@
+3
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/notification-fd.license b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/notification-fd.license
new file mode 100644
index 0000000..a941ca4
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/notification-fd.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/run b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/run
new file mode 100755
index 0000000..9041788
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/run
@@ -0,0 +1,5 @@
+#!/bin/execlineb -P
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
+
+s6-svscan -d3 instance
diff --git a/host/rootfs/etc/template/gpu/data/check b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/data/check
index 113dcf0..113dcf0 100755
--- a/host/rootfs/etc/template/gpu/data/check
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/data/check
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/notification-fd b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/notification-fd
new file mode 100644
index 0000000..00750ed
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/notification-fd
@@ -0,0 +1 @@
+3
diff --git a/host/rootfs/etc/template/gpu/notification-fd.license b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/notification-fd.license
index 2241beb..2241beb 100644
--- a/host/rootfs/etc/template/gpu/notification-fd.license
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/notification-fd.license
diff --git a/host/rootfs/etc/template/gpu/run b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/run
index eaac8d6..eaac8d6 100755
--- a/host/rootfs/etc/template/gpu/run
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/run
diff --git a/host/rootfs/etc/template/fs/type b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/type
index 5883cff..5883cff 100644
--- a/host/rootfs/etc/template/fs/type
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/type
diff --git a/host/rootfs/etc/template/gpu/type.license b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/type.license
index 2241beb..2241beb 100644
--- a/host/rootfs/etc/template/gpu/type.license
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vhost-user-gpu/template/type.license
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vmm/notification-fd b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/notification-fd
new file mode 100644
index 0000000..00750ed
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/notification-fd
@@ -0,0 +1 @@
+3
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vmm/notification-fd.license b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/notification-fd.license
new file mode 100644
index 0000000..a941ca4
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/notification-fd.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vmm/run b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/run
new file mode 100755
index 0000000..9041788
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/run
@@ -0,0 +1,5 @@
+#!/bin/execlineb -P
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
+
+s6-svscan -d3 instance
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/notification-fd b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/notification-fd
new file mode 100644
index 0000000..00750ed
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/notification-fd
@@ -0,0 +1 @@
+3
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/notification-fd.license b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/notification-fd.license
new file mode 100644
index 0000000..a941ca4
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/notification-fd.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
diff --git a/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/run b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/run
new file mode 120000
index 0000000..5438b0a
--- /dev/null
+++ b/host/rootfs/etc/s6-linux-init/run-image/service/vmm/template/run
@@ -0,0 +1 @@
+/bin/start-vmm
\ No newline at end of file
diff --git a/host/rootfs/etc/s6-rc/ext-rc-init/up b/host/rootfs/etc/s6-rc/ext-rc-init/up
index 527ba3f..0214759 100644
--- a/host/rootfs/etc/s6-rc/ext-rc-init/up
+++ b/host/rootfs/etc/s6-rc/ext-rc-init/up
@@ -2,48 +2,34 @@
 # SPDX-FileCopyrightText: 2021-2023 Alyssa Ross <hi@alyssa.is>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-if { mkdir -p /run/s6-rc.ext.src/ok-vmm/contents.d }
-if { redirfd -w 1 /run/s6-rc.ext.src/ok-vmm/type echo bundle }
-cd /run/s6-rc.ext.src
+cd /ext/svc/data
+elglob -0 names *
 
 if {
-  elglob -0 dirs /ext/svc/data/*/
-  forx -po0 -E dir { $dirs }
-  backtick -E name { basename -- $dir }
+  forx -po0 -E name { $names }
 
   if { mkdir /run/vm/${name} }
-  if { ln -s $dir /run/vm/${name}/config }
-
-  if { mkdir vm-${name} vm-${name}/dependencies.d vm-${name}/env }
-  if { redirfd -w 1 vm-${name}/type echo longrun }
-  if { redirfd -w 1 vm-${name}/notification-fd echo 3 }
-  if { redirfd -w 1 vm-${name}/run printf "#!/bin/execlineb -P\n/bin/start-vmm" }
-  if { chmod +x vm-${name}/run }
-  if { touch ok-vmm/contents.d/vm-${name} }
+  if { ln -s /ext/svc/data/${name} /run/vm/${name}/config }
 
   if {
-    elglob -0 paths ${dir}/shared-dirs/*
-    forx -po0 -E path { $paths }
-    backtick -E fsname { basename -- $path }
-    if { cp -R /etc/template/fs fs-${name}:${fsname} }
-    if { mkdir fs-${name}:${fsname}/data fs-${name}:${fsname}/env }
-    if { cp -P ${path}/dir fs-${name}:${fsname}/data/shared-dir }
-    touch vm-${name}/dependencies.d/fs-${name}:${fsname}
+    if -t { test -e ${name}/shared-dirs }
+    cd ${name}/shared-dirs
+    elglob -0 fsnames *
+
+    if {
+      forx -po0 -E fsname { $fsnames }
+      s6-instance-create /run/service/vhost-user-fs ${name}:${fsname}
+    }
+    s6-svwait -U /run/service/vhost-user-fs/instance/${name}:${fsnames}
   }
 
   if {
-    if -t { test -e ${dir}/wayland }
-    if { cp -R -- /etc/template/gpu gpu-${name} }
-    if { mkdir -- gpu-${name}/env }
-    touch -- vm-${name}/dependencies.d/gpu-${name}
+    if -t { test -e ${name}/wayland }
+    if { s6-instance-create /run/service/vhost-user-gpu $name }
+    s6-svwait -U /run/service/vhost-user-gpu/instance/${name}
   }
 
-  elglob -0 paths /ext/svc/data/${name}/providers/net/*
-  forx -po0 -E path { $paths }
-  backtick -E dep { basename -- $path }
-  touch vm-${name}/dependencies.d/vm-${dep}
+  s6-instance-create /run/service/vmm $name
 }
 
-if { s6-rc-compile /run/s6-rc.ext.db /run/s6-rc.ext.src }
-if { s6-rc-init -c /run/s6-rc.ext.db -l /run/s6-rc.ext -p ext- /run/service }
-s6-rc -ul /run/s6-rc.ext change ok-vmm
+s6-svwait -U /run/service/vmm/instance/${names}
diff --git a/host/rootfs/etc/shared-dir b/host/rootfs/etc/shared-dir
new file mode 100755
index 0000000..9c9cf4b
--- /dev/null
+++ b/host/rootfs/etc/shared-dir
@@ -0,0 +1,10 @@
+#!/bin/awk -f
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
+
+# Usage: /etc/shared-dir -v servicename=[servicename]
+
+BEGIN {
+	split(servicename, names, ":")
+	print("/ext/svc/data/" names[1] "/shared-dirs/" names[2] "/dir")
+}
diff --git a/host/rootfs/etc/template/fs/run b/host/rootfs/etc/template/fs/run
deleted file mode 100755
index 5ca214a..0000000
--- a/host/rootfs/etc/template/fs/run
+++ /dev/null
@@ -1,11 +0,0 @@
-#!/bin/execlineb -P
-# SPDX-License-Identifier: EUPL-1.2+
-# SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
-
-s6-ipcserver-socketbinder -a 0700 -B env/virtiofsd.sock
-
-if { fdmove 1 3 echo }
-fdclose 3
-
-export TMPDIR /run
-virtiofsd --fd 0 --shared-dir data/shared-dir
diff --git a/host/rootfs/etc/template/fs/type.license b/host/rootfs/etc/template/fs/type.license
deleted file mode 100644
index 5a40633..0000000
--- a/host/rootfs/etc/template/fs/type.license
+++ /dev/null
@@ -1,2 +0,0 @@
-SPDX-License-Identifier: CC0-1.0
-SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
diff --git a/host/rootfs/etc/template/gpu/type b/host/rootfs/etc/template/gpu/type
deleted file mode 100644
index 5883cff..0000000
--- a/host/rootfs/etc/template/gpu/type
+++ /dev/null
@@ -1 +0,0 @@
-longrun
diff --git a/host/rootfs/usr/bin/lsvm b/host/rootfs/usr/bin/lsvm
index a2b2b2b..a9b25ce 100755
--- a/host/rootfs/usr/bin/lsvm
+++ b/host/rootfs/usr/bin/lsvm
@@ -11,7 +11,7 @@ if -n {
   redirfd -w 2 /dev/null
   backtick -E state {
     pipeline -w { jq -r .state }
-    ch-remote --api-socket /run/service/ext-vm-${vm}/env/cloud-hypervisor.sock info
+    ch-remote --api-socket /run/service/vmm/instance/${vm}/env/cloud-hypervisor.sock info
   }
   case -s $state {
     Created { echo "STOPPED" }
diff --git a/host/rootfs/usr/bin/vm-console b/host/rootfs/usr/bin/vm-console
index 00d823c..0f850be 100755
--- a/host/rootfs/usr/bin/vm-console
+++ b/host/rootfs/usr/bin/vm-console
@@ -4,7 +4,7 @@
 
 backtick -E pty {
   pipeline -w { jq -r .config.console.file }
-  ch-remote --api-socket /run/service/ext-vm-${1}/env/cloud-hypervisor.sock info
+  ch-remote --api-socket /run/service/vmm/instance/${1}/env/cloud-hypervisor.sock info
 }
 
 foreground {
diff --git a/host/rootfs/usr/bin/vm-start b/host/rootfs/usr/bin/vm-start
index effc65d..81437a2 100755
--- a/host/rootfs/usr/bin/vm-start
+++ b/host/rootfs/usr/bin/vm-start
@@ -12,4 +12,4 @@ foreground {
   vm-start $provider
 }
 
-ch-remote --api-socket /run/service/ext-vm-${1}/env/cloud-hypervisor.sock boot
+ch-remote --api-socket /run/service/vmm/instance/${1}/env/cloud-hypervisor.sock boot
diff --git a/host/rootfs/usr/bin/vm-stop b/host/rootfs/usr/bin/vm-stop
index db2e9f3..61b5a11 100755
--- a/host/rootfs/usr/bin/vm-stop
+++ b/host/rootfs/usr/bin/vm-stop
@@ -2,4 +2,4 @@
 # SPDX-License-Identifier: EUPL-1.2+
 # SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
 
-ch-remote --api-socket /run/service/ext-vm-${1}/env/cloud-hypervisor.sock shutdown
+ch-remote --api-socket /run/service/vmm/instance/${1}/env/cloud-hypervisor.sock shutdown
diff --git a/host/start-vmm/ch.rs b/host/start-vmm/ch.rs
index 0ef1354..cc05d84 100644
--- a/host/start-vmm/ch.rs
+++ b/host/start-vmm/ch.rs
@@ -73,7 +73,7 @@ pub struct VmConfig {
 }
 
 fn command(vm_name: &str, s: impl AsRef<OsStr>) -> Command {
-    let mut api_socket_path = OsString::from("/run/service/ext-vm-");
+    let mut api_socket_path = OsString::from("/run/service/vmm/instance/");
     api_socket_path.push(vm_name);
     api_socket_path.push("/env/cloud-hypervisor.sock");
 
diff --git a/host/start-vmm/lib.rs b/host/start-vmm/lib.rs
index 34d385b..837e3d5 100644
--- a/host/start-vmm/lib.rs
+++ b/host/start-vmm/lib.rs
@@ -116,7 +116,7 @@ pub fn vm_config(vm_name: &str, config_root: &Path) -> Result<VmConfig, String>
 
                     Ok(FsConfig {
                         tag: entry.to_string(),
-                        socket: format!("../fs-{vm_name}:{entry}/env/virtiofsd.sock"),
+                        socket: format!("/run/service/vhost-user-fs/instance/{vm_name}:{entry}/env/virtiofsd.sock"),
                     })
                 })
                 .collect::<Result<_, String>>()?,
@@ -125,7 +125,7 @@ pub fn vm_config(vm_name: &str, config_root: &Path) -> Result<VmConfig, String>
         },
         gpu: match wayland_path.try_exists() {
             Ok(true) => vec![GpuConfig {
-                socket: format!("../gpu-{vm_name}/env/crosvm.sock"),
+                socket: format!("/run/service/vhost-user-gpu/instance/{vm_name}/env/crosvm.sock"),
             }],
             Ok(false) => vec![],
             Err(e) => return Err(format!("checking for existence of {:?}: {e}", wayland_path)),
@@ -203,15 +203,10 @@ pub fn create_vm(dir: &Path, config_root: &Path) -> Result<(), String> {
         .to_str()
         .ok_or_else(|| format!("VM name {:?} is not valid UTF-8", vm_name))?;
 
-    if !vm_name.starts_with("vm-") {
-        return Err("not running from a VM service directory".to_string());
-    }
-
     if vm_name.contains(':') {
         return Err(format!("VM name may not contain a colon: {:?}", vm_name));
     }
 
-    let vm_name = &vm_name[3..];
     let config = vm_config(vm_name, config_root)?;
 
     // SAFETY: safe because we ensure we don't violate any invariants
@@ -239,7 +234,7 @@ mod tests {
 
     #[test]
     fn test_vm_name_colon() {
-        let e = create_vm(Path::new("/vm-:"), Path::new("/")).unwrap_err();
+        let e = create_vm(Path::new("/:vm"), Path::new("/")).unwrap_err();
         assert!(e.contains("colon"), "unexpected error: {:?}", e);
     }
 }
diff --git a/host/start-vmm/tests/vm_command-shared-dir.rs b/host/start-vmm/tests/vm_command-shared-dir.rs
index 7da7843..d446d5f 100644
--- a/host/start-vmm/tests/vm_command-shared-dir.rs
+++ b/host/start-vmm/tests/vm_command-shared-dir.rs
@@ -41,7 +41,7 @@ fn main() -> std::io::Result<()> {
     assert_eq!(actual_tags, expected_tags);
 
     let expected_sockets = (1..=2)
-        .map(|i| format!("../fs-testvm:dir{i}/env/virtiofsd.sock"))
+        .map(|i| format!("/run/service/vhost-user-fs/instance/testvm:dir{i}/env/virtiofsd.sock"))
         .collect();
     assert_eq!(actual_sockets, expected_sockets);