Use QEMU's standard VGA instead of virtio-vga

On Arch, -vga virtio needs qemu-hw-display-virtio-vga and also
qemu-hw-display-virtio-gpu, which that package doesn't depend on; with only
the first, QEMU segfaults at start without a message. The smoketest's VMs
are headless (or VNC), so -vga std, which qemu-base has, is enough. This
reverts 2207208's extra package and checks.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/common.sh

@@ -62,12 +62,6 @@ in_flatpak() {
   [ -f /.flatpak-info ] || [ -n "${FLATPAK_ID:-}" ]
 }
 
-# Whether QEMU has the display the smoketest's VMs start with (-vga virtio).
-# Arch packages it apart from qemu-base, as qemu-hw-display-virtio-vga.
-qemu_has_virtio_vga() {
-  [[ "$(qemu-system-x86_64 -device help 2> /dev/null)" == *'name "virtio-vga"'* ]]
-}
-
 # This project's folder
 sibling_dir() {
   cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd

lib/doctor.sh

@@ -50,15 +50,6 @@ cmd_doctor() {
     problem "not installed: ${missing[*]}" "fix: bash $(sibling_dir)/update.sh"
   fi
 
-  if command -v qemu-system-x86_64 &> /dev/null; then
-    if qemu_has_virtio_vga; then
-      ok "QEMU has the virtio-vga display the smoketest's VMs use"
-    else
-      problem "QEMU has no virtio-vga display, so the smoketest's VMs won't start" \
-        "fix: bash $(sibling_dir)/update.sh"
-    fi
-  fi
-
   if [ -r /dev/kvm ] && [ -w /dev/kvm ]; then
     ok "KVM is available for the smoketest's virtual machines"
   else

lib/smoketest.sh

@@ -56,8 +56,6 @@ require_vm_tools() {
     command -v "$tool" &> /dev/null \
       || die "$tool isn't installed. Install coredesktop-dev's packages: bash $(sibling_dir)/update.sh"
   done
-  qemu_has_virtio_vga \
-    || die "QEMU has no virtio-vga display. Install coredesktop-dev's packages: bash $(sibling_dir)/update.sh"
   [ -r "$KVM_DEVICE" ] && [ -w "$KVM_DEVICE" ] \
     || die "Can't use $KVM_DEVICE. Turn on virtualization (VT-x/AMD-V) in the firmware settings."
 }

lib/vm.sh

@@ -76,7 +76,7 @@ vm_start() {
     -drive "file=$disk,if=virtio,format=qcow2,discard=unmap" \
     -nic "user,model=virtio-net-pci,hostfwd=tcp:127.0.0.1:$VM_PORT-:22" \
     -virtfs "local,path=$PKG_CACHE,mount_tag=pkgcache,security_model=mapped-xattr" \
-    -vga virtio \
+    -vga std \
     "${display[@]}" \
     -serial "file:$VM_DIR/serial.log" \
     -pidfile "$VM_DIR/qemu.pid" \