From 723c89af670c3574374f4c1800ba072267a3d1eb Mon Sep 17 00:00:00 2001
From: Gunnar Beutner <gunnar@beutner.name>
Date: Wed, 4 Aug 2021 01:39:14 +0200
Subject: [PATCH] Meta: Automatically enable WHPX when possible

---
 Documentation/BuildInstructionsWindows.md |  8 ++-----
 Meta/run.sh                               | 27 ++++++++++++++---------
 2 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/Documentation/BuildInstructionsWindows.md b/Documentation/BuildInstructionsWindows.md
index 45e74fad32cbf4..e8ca0b329bb6d7 100644
--- a/Documentation/BuildInstructionsWindows.md
+++ b/Documentation/BuildInstructionsWindows.md
@@ -48,10 +48,6 @@ following command in an elevated PowerShell session: \
 
 ![WHPX Windows Feature](WHPX_Feature.png)
 
-Set the `SERENITY_VIRT_TECH_ARG` environment variable in your WSL2 shell: \
-`export SERENITY_VIRT_TECH_ARG="-accel whpx,kernel-irqchip=off"`
+You may have to reboot after enabling the WHPX feature.
 
-You might want to add those environment variables to your shell's configuration file, so that you don't have to set them
-manually each time you start a new shell.
-
-Start the VM with `Meta/serenity.sh run` as usual.
+Afterwards you can start the VM with `Meta/serenity.sh run` as usual.
diff --git a/Meta/run.sh b/Meta/run.sh
index a2ba475a35fbd3..38a7f5a08d0329 100755
--- a/Meta/run.sh
+++ b/Meta/run.sh
@@ -60,16 +60,6 @@ fi
 
 [ -z "$SERENITY_RAM_SIZE" ] && SERENITY_RAM_SIZE=512M
 
-if command -v wslpath >/dev/null; then
-    case "$SERENITY_QEMU_BIN" in
-        /mnt/?/*)
-            [ -z "$SERENITY_QEMU_CPU" ] && SERENITY_QEMU_CPU="max,vmx=off"
-            SERENITY_KERNEL_CMDLINE="$SERENITY_KERNEL_CMDLINE disable_virtio"
-    esac
-fi
-
-[ -z "$SERENITY_QEMU_CPU" ] && SERENITY_QEMU_CPU="max"
-
 [ -z "$SERENITY_DISK_IMAGE" ] && {
     if [ "$SERENITY_RUN" = qgrub ]; then
         SERENITY_DISK_IMAGE="grub_disk_image"
@@ -100,6 +90,23 @@ if [ "$installed_major_version" -lt "$SERENITY_QEMU_MIN_REQ_VERSION" ]; then
     die
 fi
 
+if command -v wslpath >/dev/null; then
+    case "$SERENITY_QEMU_BIN" in
+        /mnt/?/*)
+            if [ -z "$SERENITY_VIRT_TECH_ARG" ]; then
+                if [ "$installed_major_version" -gt 5 ]; then
+                    SERENITY_VIRT_TECH_ARG="-accel whpx,kernel-irqchip=off -accel tcg"
+                else
+                    SERENITY_VIRT_TECH_ARG="-accel whpx -accel tcg"
+                fi
+            fi
+            [ -z "$SERENITY_QEMU_CPU" ] && SERENITY_QEMU_CPU="max,vmx=off"
+            SERENITY_KERNEL_CMDLINE="$SERENITY_KERNEL_CMDLINE disable_virtio"
+    esac
+fi
+
+[ -z "$SERENITY_QEMU_CPU" ] && SERENITY_QEMU_CPU="max"
+
 if [ -z "$SERENITY_SPICE" ] && "${SERENITY_QEMU_BIN}" -chardev help | grep -iq qemu-vdagent; then
     SERENITY_SPICE_SERVER_CHARDEV="-chardev qemu-vdagent,clipboard=on,mouse=off,id=vdagent,name=vdagent"
 elif "${SERENITY_QEMU_BIN}" -chardev help | grep -iq spicevmc; then