Re: [Qemu-devel] [PATCH 03/38] event_notifier: Make event_notifier_init_fd() #ifdef CONFIG_EVENTFD

[Marc-André Lureau]

Hi

On Mon, Feb 29, 2016 at 7:40 PM, Markus Armbruster <address@hidden> wrote:
> Event notifiers are designed for eventfd(2).  They can fall back to
> pipes, but according to Paolo, event_notifier_init_fd() really
> requires the real thing, and should therefore be under #ifdef
> CONFIG_EVENTFD.  Do that.
>
> Its only user is ivshmem, which is currently CONFIG_POSIX.  Narrow it
> to CONFIG_EVENTFD.
>
> Cc: Paolo Bonzini <address@hidden>
> Signed-off-by: Markus Armbruster <address@hidden>
> ---
>  default-configs/pci.mak     | 2 +-
>  util/event_notifier-posix.c | 6 ++++++
>  2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/default-configs/pci.mak b/default-configs/pci.mak
> index 4fa9a28..9c8bc68 100644
> --- a/default-configs/pci.mak
> +++ b/default-configs/pci.mak
> @@ -36,5 +36,5 @@ CONFIG_SDHCI=y
>  CONFIG_EDU=y
>  CONFIG_VGA=y
>  CONFIG_VGA_PCI=y
> -CONFIG_IVSHMEM=$(CONFIG_POSIX)
> +CONFIG_IVSHMEM=$(CONFIG_EVENTFD)

This narrows ivshmem to eventfd os only. Eventually after the split,
it is easier to bring back posix for ivshmem-plain, but it's important
to highlight this change.

>  CONFIG_ROCKER=y
> diff --git a/util/event_notifier-posix.c b/util/event_notifier-posix.c
> index 2e30e74..c9657a6 100644
> --- a/util/event_notifier-posix.c
> +++ b/util/event_notifier-posix.c
> @@ -20,11 +20,17 @@
>  #include <sys/eventfd.h>
>  #endif
>
> +#ifdef CONFIG_EVENTFD
> +/*
> + * Initialize @e with existing file descriptor @fd.
> + * @fd must be a genuine eventfd object, emulation with pipe won't do.
> + */
>  void event_notifier_init_fd(EventNotifier *e, int fd)
>  {
>      e->rfd = fd;
>      e->wfd = fd;
>  }
> +#endif
>
>  int event_notifier_init(EventNotifier *e, int active)
>  {
> --
> 2.4.3
>
>



-- 
Marc-André Lureau