Re: [PATCH v5 10/11] 9p: darwin: meson: Allow VirtFS on Darwin

[Christian Schoenebeck <qemu_oss@crudebyte.com>]

On Montag, 7. Februar 2022 23:40:23 CET Will Cohen wrote:
> 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
>              - 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 5f43355071..c1d13209ff 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1421,17 +1421,23 @@ 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 Darwin requires the presence of pthread_fchdir_np')

Maybe call this "macOS" in this error message as well?

    error('virtio-9p (virtfs) requires the presence of pthread_fchdir_np on macOS')

>      elif not libcap_ng.found() or not libattr.found()
>        error('virtio-9p (virtfs) requires libcap-ng-devel and
> libattr-devel') elif not have_system