Documentation+Meta: Automatically set vmx=off on Windows

Documentation/BuildInstructionsWindows.md

@@ -51,9 +51,6 @@ To run SerenityOS in a WHPX-enabled QEMU VM:
 - Specify QEMU acceleration option: \
 `export SERENITY_VIRT_TECH_ARG="-accel whpx,kernel-irqchip=off"`
 
-- Disable Virtual Machine eXtensions on the vCPU, otherwise some versions of QEMU will crash out with a "WHPX: Unexpected VP exit code 4" error: \
-`export SERENITY_QEMU_CPU="max,vmx=off"`
-
 - Start the VM with `Meta/serenity.sh run` as usual.
 
 ### Known issues with WHPX

Meta/run.sh

@@ -49,6 +49,13 @@ fi
 
 [ -z "$SERENITY_RAM_SIZE" ] && SERENITY_RAM_SIZE=512M
 
+if command -v wslpath >/dev/null; then
+    case "$SERENITY_QEMU_BIN" in
+        /mnt/c/*)
+            [ -z "$SERENITY_QEMU_CPU" ] && SERENITY_QEMU_CPU="max,vmx=off"
+    esac
+fi
+
 [ -z "$SERENITY_QEMU_CPU" ] && SERENITY_QEMU_CPU="max"
 
 [ -z "$SERENITY_DISK_IMAGE" ] && {