meson: list leftover CONFIG_* symbols

There are no config-host.mak symbols anymore that are needed in
config-host.h; the only symbols that are included in config_host_data via
the foreach loop are:

- CONFIG_DEFAULT_TARGETS, which is not used by C code.

- CONFIG_TCG and CONFIG_TCG_INTERPRETER, which are not part of config-host.mak

So, list these two symbols explicitly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

docs/devel/build-system.rst

@@ -460,17 +460,13 @@ Built by configure:
 
 ``config-host.mak``
   When configure has determined the characteristics of the build host it
-  will write them to this file for use in ``Makefile`` and to a smaller
-  extent ``meson.build``. These include the paths to various tools and a
-  variety of ``CONFIG_*`` variables related to optionally enabled features.
+  will write the paths to various tools to this file, for use in ``Makefile``
+  and to a smaller extent ``meson.build``.
 
   ``config-host.mak`` is also used as a dependency checking mechanism. If make
   sees that the modification timestamp on configure is newer than that on
   ``config-host.mak``, then configure will be re-run.
 
-  The variables defined here apply to all QEMU
-  build outputs.
-
 ``config-meson.cross``
 
   A Meson "cross file" (or native file) used to communicate the paths to

meson.build

@@ -691,7 +691,6 @@ if get_option('tcg').allowed()
   endif
   if get_option('tcg_interpreter')
     tcg_arch = 'tci'
-    config_host += { 'CONFIG_TCG_INTERPRETER': 'y' }
   elif host_arch == 'x86_64'
     tcg_arch = 'i386'
   elif host_arch == 'ppc64'
@@ -701,7 +700,6 @@ if get_option('tcg').allowed()
                         language: all_languages)
 
   accelerators += 'CONFIG_TCG'
-  config_host += { 'CONFIG_TCG': 'y' }
 endif
 
 if 'CONFIG_KVM' not in accelerators and get_option('kvm').enabled()
@@ -2132,6 +2130,10 @@ if seccomp.found()
 endif
 config_host_data.set('CONFIG_SNAPPY', snappy.found())
 config_host_data.set('CONFIG_SOLARIS', targetos == 'sunos')
+if get_option('tcg').allowed()
+  config_host_data.set('CONFIG_TCG', 1)
+  config_host_data.set('CONFIG_TCG_INTERPRETER', tcg_arch == 'tci')
+endif
 config_host_data.set('CONFIG_TPM', have_tpm)
 config_host_data.set('CONFIG_TSAN', get_option('tsan'))
 config_host_data.set('CONFIG_USB_LIBUSB', libusb.found())
@@ -2760,12 +2762,6 @@ if targetos == 'windows' and 'cpp' in all_languages
 endif
 config_host_data.set('HAVE_VSS_SDK', have_vss_sdk)
 
-foreach k, v: config_host
-  if k.startswith('CONFIG_')
-    config_host_data.set(k, v == 'y' ? 1 : v)
-  endif
-endforeach
-
 # Older versions of MinGW do not import _lock_file and _unlock_file properly.
 # This was fixed for v6.0.0 with commit b48e3ac8969d.
 if targetos == 'windows'