Don't require libcap-ng for virtfs support

It's only required for the proxy helper.

Add a new option for the proxy helper rather than enabling it
implicitly.

Change-Id: I95b73fca625529e99d16b0a64e01c65c0c1d43f2
Signed-off-by: Peter Foley <pefoley@google.com>
Message-Id: <20230503130757.863824-1-pefoley@google.com>
[C.S.: - Resolve merge conflict. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>

3 files changed, 15 insertions, 3 deletions

diff --git a/meson.build b/meson.build
index 25a4b9f..c6b0514 100644
--- a/meson.build
+++ b/meson.build
@@ -1766,12 +1766,17 @@ have_virtfs = get_option('virtfs') \
              error_message: 'virtio-9p (virtfs) requires Linux or macOS') \
     .require(targetos == 'linux' or cc.has_function('pthread_fchdir_np'),
              error_message: 'virtio-9p (virtfs) on macOS requires the presence of pthread_fchdir_np') \
-    .require(targetos == 'darwin' or (libattr.found() and libcap_ng.found()),
-             error_message: 'virtio-9p (virtfs) on Linux requires libcap-ng-devel and libattr-devel') \
+    .require(targetos == 'darwin' or libattr.found(),
+             error_message: 'virtio-9p (virtfs) on Linux requires libattr-devel') \
     .disable_auto_if(not have_tools and not have_system) \
     .allowed()
 
-have_virtfs_proxy_helper = targetos != 'darwin' and have_virtfs and have_tools
+have_virtfs_proxy_helper = get_option('virtfs_proxy_helper') \
+    .require(targetos != 'darwin', error_message: 'the virtfs proxy helper is incompatible with macOS') \
+    .require(have_virtfs, error_message: 'the virtfs proxy helper requires that virtfs is enabled') \
+    .disable_auto_if(not have_tools) \
+    .require(libcap_ng.found(), error_message: 'the virtfs proxy helper requires libcap-ng') \
+    .allowed()
 
 if get_option('block_drv_ro_whitelist') == ''
   config_host_data.set('CONFIG_BDRV_RO_WHITELIST', '')
@@ -3926,6 +3931,7 @@ if have_block
   summary_info += {'Block whitelist (ro)': get_option('block_drv_ro_whitelist')}
   summary_info += {'Use block whitelist in tools': get_option('block_drv_whitelist_in_tools')}
   summary_info += {'VirtFS support':    have_virtfs}
+  summary_info += {'VirtFS Proxy Helper support': have_virtfs_proxy_helper}
   summary_info += {'Live block migration': config_host_data.get('CONFIG_LIVE_BLOCK_MIGRATION')}
   summary_info += {'replication support': config_host_data.get('CONFIG_REPLICATION')}
   summary_info += {'bochs support':     get_option('bochs').allowed()}
diff --git a/meson_options.txt b/meson_options.txt
index d8330a1..11aec2a 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -274,6 +274,8 @@ option('vhost_user_blk_server', type: 'feature', value: 'auto',
        description: 'build vhost-user-blk server')
 option('virtfs', type: 'feature', value: 'auto',
        description: 'virtio-9p support')
+option('virtfs_proxy_helper', type: 'feature', value: 'auto',
+       description: 'virtio-9p proxy helper support')
 option('libvduse', type: 'feature', value: 'auto',
        description: 'build VDUSE Library')
 option('vduse_blk_export', type: 'feature', value: 'auto',
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 2805d1c..52fb079 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -181,6 +181,8 @@ meson_options_help() {
   printf "%s\n" '  vhost-vdpa      vhost-vdpa kernel backend support'
   printf "%s\n" '  virglrenderer   virgl rendering support'
   printf "%s\n" '  virtfs          virtio-9p support'
+  printf "%s\n" '  virtfs-proxy-helper'
+  printf "%s\n" '                  virtio-9p proxy helper support'
   printf "%s\n" '  vmdk            vmdk image format support'
   printf "%s\n" '  vmnet           vmnet.framework network backend support'
   printf "%s\n" '  vnc             VNC server'
@@ -474,6 +476,8 @@ _meson_option_parse() {
     --disable-virglrenderer) printf "%s" -Dvirglrenderer=disabled ;;
     --enable-virtfs) printf "%s" -Dvirtfs=enabled ;;
     --disable-virtfs) printf "%s" -Dvirtfs=disabled ;;
+    --enable-virtfs-proxy-helper) printf "%s" -Dvirtfs_proxy_helper=enabled ;;
+    --disable-virtfs-proxy-helper) printf "%s" -Dvirtfs_proxy_helper=disabled ;;
     --enable-vmdk) printf "%s" -Dvmdk=enabled ;;
     --disable-vmdk) printf "%s" -Dvmdk=disabled ;;
     --enable-vmnet) printf "%s" -Dvmnet=enabled ;;