accel: build tcg modular

Build tcg accel ops as module.
Which is only a small fraction of tcg.
Also only x86 for now.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jose R. Ziviani <jziviani@suse.de>
Message-Id: <20210624103836.2382472-30-kraxel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/meson.build b/meson.build
index c943e44..d9aa2d7 100644
--- a/meson.build
+++ b/meson.build
@@ -92,6 +92,8 @@
   }
 endif
 
+modular_tcg = ['i386-softmmu', 'x86_64-softmmu']
+
 edk2_targets = [ 'arm-softmmu', 'aarch64-softmmu', 'i386-softmmu', 'x86_64-softmmu' ]
 install_edk2_blobs = false
 if get_option('install_blobs')
@@ -1531,6 +1533,11 @@
       elif sym == 'CONFIG_XEN' and have_xen_pci_passthrough
         config_target += { 'CONFIG_XEN_PCI_PASSTHROUGH': 'y' }
       endif
+      if target in modular_tcg
+        config_target += { 'CONFIG_TCG_MODULAR': 'y' }
+      else
+        config_target += { 'CONFIG_TCG_BUILTIN': 'y' }
+      endif
       accel_kconfig += [ sym + '=y' ]
     endif
   endforeach
@@ -2002,6 +2009,7 @@
 
 # accel modules
 qtest_module_ss = ss.source_set()
+tcg_module_ss = ss.source_set()
 
 modules = {}
 target_modules = {}
@@ -2242,7 +2250,11 @@
 subdir('tests/qtest/fuzz')
 
 # accel modules
-target_modules += { 'accel' : { 'qtest': qtest_module_ss }}
+tcg_real_module_ss = ss.source_set()
+tcg_real_module_ss.add_all(when: 'CONFIG_TCG_MODULAR', if_true: tcg_module_ss)
+specific_ss.add_all(when: 'CONFIG_TCG_BUILTIN', if_true: tcg_module_ss)
+target_modules += { 'accel' : { 'qtest': qtest_module_ss,
+                                'tcg': tcg_real_module_ss }}
 
 ########################
 # Library dependencies #