From 01fca96f283c984d91fe8cabad891b6a40d205f3 Mon Sep 17 00:00:00 2001
From: Martin Wimpress <code@flexion.org>
Date: Wed, 29 Sep 2021 03:30:16 +0100
Subject: [PATCH] Add support for virtio-9p

---
 README.md |  4 ++--
 quickemu  | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 0f6468d..364bd24 100644
--- a/README.md
+++ b/README.md
@@ -183,6 +183,7 @@ There are some considerations when running macOS via Quickemu.
     * `vmxnet3` network device is used.
   * USB host pass-through is limited to UHCI (USB 2.0)
   * Display resolution can only be changed via macOS System Preferences.
+  * File sharing between guest and host is available via [virtio-9p](https://wiki.qemu.org/Documentation/9psetup).
   * **SPICE has limited supported on macOS**:
     * Copy/paste via SPICE agent is not available.
     * File sharing via SPICE webdavd is not available.
@@ -417,7 +418,6 @@ used the 1920x1080 monitor which results in a window size of 1664x936.
 
 # TODO
 
-  - [ ] Add 9p support
   - [ ] Add `spice-app` support via `virt-viewer`; *requires `virt-viewer` 8.0 or newer*
   - [ ] Add support for `ignore_msrs` for macOS. `echo "options kvm ignore_msrs=Y" >> /etc/modprobe.d/kvm.conf && update-initramfs -k all -u`
   - [ ] Add discrete GPU pass-through
@@ -447,8 +447,8 @@ Useful reference that assisted the development of Quickemu.
     * <https://turlucode.com/qemu-command-line-args/>
     * <https://github.com/pbatard/Fido>
   * 9p & virtiofs
+    * <https://wiki.qemu.org/Documentation/9p>
     * <https://wiki.qemu.org/Documentation/9psetup>
-    * <https://www.linux-kvm.org/page/9p_virtio>
     * <https://www.kraxel.org/blog/2019/06/macos-qemu-guest/>
     * <https://superuser.com/questions/628169/how-to-share-a-directory-with-the-host-without-networking-in-qemu>
     * <https://virtio-fs.gitlab.io/>
diff --git a/quickemu b/quickemu
index e2f56ff..d3d0eaa 100755
--- a/quickemu
+++ b/quickemu
@@ -467,6 +467,17 @@ function vm_boot() {
     if [ "${guest_os}" != "macos" ]; then
       echo " - WebDAV:   ${PUBLIC} via: dav://localhost:9843/"
     fi
+
+    if [ "${guest_os}" != "windows" ]; then
+      echo -n " - 9P:       ${PUBLIC} via: "
+      if [ "${guest_os}" == "linux" ]; then
+        echo "sudo mount -t 9p -o trans=virtio,version=9p2000.L,msize=104857600 ${USER}-public ~/Public"
+      elif [ "${guest_os}" == "macos" ]; then
+        # PUBLICSHARE needs to be world writeable for seamless integration with
+        # macOS. Test if it is is world writeable, and prompt what to do if not.
+        echo "sudo mount_9p ${USER}-public"
+      fi
+    fi
   fi
 
   enable_usb_passthrough
@@ -565,6 +576,14 @@ function vm_boot() {
           -object rng-random,id=rng0,filename=/dev/urandom)
   fi
 
+  # https://wiki.qemu.org/Documentation/9psetup
+  # https://askubuntu.com/questions/772784/9p-libvirt-qemu-share-modes
+  if [ "${guest_os}" != "windows" ]; then
+      # shellcheck disable=SC2054
+      args+=(-fsdev local,id=fsdev0,path="${PUBLIC}",security_model=mapped-xattr
+             -device virtio-9p-pci,fsdev=fsdev0,mount_tag="${USER}-public")
+  fi
+
   if [ -n "${USB_PASSTHROUGH}" ]; then
     # shellcheck disable=SC2054,SC2206
     args+=(-device ${USB_HOST_PASSTHROUGH_CONTROLLER},id=hostpass