[PATCH v8 11/11] 9p: darwin: meson: Allow VirtFS on Darwin

[Will Cohen <wwcohen@gmail.com>]

From: Keno Fischer <keno@juliacomputing.com>

To allow VirtFS on darwin, we need to check that pthread_fchdir_np is
available, which has only been available since macOS 10.12.

Additionally, virtfs_proxy_helper is disabled on Darwin. This patch
series does not currently provide an implementation of the proxy-helper,
but this functionality could be implemented later on.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
[Michael Roitzsch: - Rebase for NixOS]
Signed-off-by: Michael Roitzsch <reactorcontrol@icloud.com>
[Will Cohen: - Rebase to master]
Signed-off-by: Will Cohen <wwcohen@gmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
[Will Cohen: - Add check for pthread_fchdir_np to virtfs
             - Add comments to patch commit
             - Note that virtfs_proxy_helper does not work
               on macOS
             - Fully adjust meson virtfs error note to specify
               macOS]
Signed-off-by: Will Cohen <wwcohen@gmail.com>
---
 fsdev/meson.build |  1 +
 meson.build       | 14 ++++++++++----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/fsdev/meson.build b/fsdev/meson.build
index adf57cc43e..b632b66348 100644
--- a/fsdev/meson.build
+++ b/fsdev/meson.build
@@ -7,6 +7,7 @@ fsdev_ss.add(when: ['CONFIG_FSDEV_9P'], if_true: files(
   'qemu-fsdev.c',
 ), if_false: files('qemu-fsdev-dummy.c'))
 softmmu_ss.add_all(when: 'CONFIG_LINUX', if_true: fsdev_ss)
+softmmu_ss.add_all(when: 'CONFIG_DARWIN', if_true: fsdev_ss)
 
 if have_virtfs_proxy_helper
   executable('virtfs-proxy-helper',
diff --git a/meson.build b/meson.build
index 6fdc0281ad..b6f5c57487 100644
--- a/meson.build
+++ b/meson.build
@@ -1416,17 +1416,23 @@ if not get_option('dbus_display').disabled()
   endif
 endif
 
-have_virtfs = (targetos == 'linux' and
+if targetos == 'darwin' and cc.has_function('pthread_fchdir_np')
+  have_virtfs = have_system
+else
+  have_virtfs = (targetos == 'linux' and
     have_system and
     libattr.found() and
     libcap_ng.found())
+endif
 
-have_virtfs_proxy_helper = have_virtfs and have_tools
+have_virtfs_proxy_helper = targetos != 'darwin' and have_virtfs and have_tools
 
 if get_option('virtfs').enabled()
   if not have_virtfs
-    if targetos != 'linux'
-      error('virtio-9p (virtfs) requires Linux')
+    if targetos != 'linux' and targetos != 'darwin'
+      error('virtio-9p (virtfs) requires Linux or macOS')
+    elif targetos == 'darwin' and not cc.has_function('pthread_fchdir_np')
+      error('virtio-9p (virtfs) on macOS requires the presence of pthread_fchdir_np')
     elif not libcap_ng.found() or not libattr.found()
       error('virtio-9p (virtfs) requires libcap-ng-devel and libattr-devel')
     elif not have_system
-- 
2.35.1