[PATCH 06/22] img/app: add support for testing virtiofs

[Alyssa Ross <hi@alyssa.is>]

Signed-off-by: Alyssa Ross <hi@alyssa.is>
---
 .gitignore        |  5 ++++-
 img/app/Makefile  | 19 ++++++++++++++++---
 img/app/shell.nix |  6 +++++-
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index a97f309..802df73 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,10 @@
 # SPDX-License-Identifier: CC0-1.0
-# SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
+# SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
 /config.nix
 build/
 result
 result-*
+
+# s6-ipcserver-socketbinder creates lockfiles for sockets.
+*.sock.lock
diff --git a/img/app/Makefile b/img/app/Makefile
index c5a4684..7d8e1c1 100644
--- a/img/app/Makefile
+++ b/img/app/Makefile
@@ -5,7 +5,10 @@
 # Nixpkgs.  If you don't have qemu-kvm, you'll need to set e.g.
 # QEMU_KVM = qemu-system-x86_64 -enable-kvm.
 QEMU_KVM = qemu-kvm
+BACKGROUND = background
 CLOUD_HYPERVISOR = cloud-hypervisor
+S6_IPCSERVER_SOCKETBINDER = s6-ipcserver-socketbinder
+VIRTIOFSD = virtiofsd
 
 prefix = /usr/local
 imgdir = $(prefix)/img
@@ -94,25 +97,35 @@ build/etc/s6-rc: $(VM_S6_RC_FILES)
 	    s6-rc-compile $@ $$dir; \
 	    exit=$$?; rm -r $$dir; exit $$exit
 
-run-qemu: build/host/appvm/blk/root.img
+start-virtiofsd:
+	$(S6_IPCSERVER_SOCKETBINDER) -B virtiofsd.sock \
+	    $(BACKGROUND) $(VIRTIOFSD) --fd 0 --shared-dir . ""
+.PHONY: start-virtiofsd
+
+run-qemu: build/host/appvm/blk/root.img start-virtiofsd
 	$(QEMU_KVM) -m 128 -cpu host -machine q35,kernel=$(KERNEL) -vga none \
 	  -drive file=build/host/appvm/blk/root.img,if=virtio,format=raw,readonly=on \
 	  -drive file=$(RUN_IMG),if=virtio,format=raw,readonly=on \
 	  -append "console=ttyS0 root=PARTLABEL=root" \
 	  -netdev user,id=net0 \
 	  -device virtio-net,netdev=net0,mac=0A:B3:EC:00:00:00 \
+	  -chardev socket,id=virtiofsd,path=virtiofsd.sock \
+	  -device vhost-user-fs-pci,chardev=virtiofsd,tag=virtiofs0 \
+	  -object memory-backend-memfd,id=mem,size=128M,share=on \
+	  -numa node,memdev=mem \
 	  -chardev vc,id=virtiocon0 \
 	  -device virtio-serial-pci \
 	  -device virtconsole,chardev=virtiocon0
 .PHONY: run-qemu
 
-run-cloud-hypervisor: build/host/appvm/blk/root.img
+run-cloud-hypervisor: build/host/appvm/blk/root.img start-virtiofsd
 	$(CLOUD_HYPERVISOR) \
 	    --api-socket path=vmm.sock \
-	    --memory size=128M \
+	    --memory size=128M,shared=on \
 	    --disk path=build/host/appvm/blk/root.img,readonly=on \
 	           path=$(RUN_IMG),readonly=on \
 	    --net tap=tap0,mac=0A:B3:EC:00:00:00 \
+	    --fs tag=virtiofs0,socket=virtiofsd.sock \
 	    --kernel $(KERNEL) \
 	    --cmdline "console=ttyS0 root=PARTLABEL=root" \
 	    --console tty \
diff --git a/img/app/shell.nix b/img/app/shell.nix
index 83dcd76..60ca465 100644
--- a/img/app/shell.nix
+++ b/img/app/shell.nix
@@ -12,7 +12,11 @@ with config.pkgs;
 
 {
   nativeBuildInputs = nativeBuildInputs ++ [
-    cloud-hypervisor jq qemu_kvm reuse
+    # Both QEMU and virtiofsd come with a virtiofsd executable,
+    # so we have to list virtiofsd first.
+    virtiofsd
+
+    cloud-hypervisor execline jq qemu_kvm reuse s6
   ];
 
   KERNEL = "${passthru.kernel.dev}/vmlinux";
-- 
2.37.1