Re: [Qemu-devel] Bug AioContext polling is not implemented on Windows with qemu-system-ppc.exe

[Howard Spoelstra]

> Hi, Howard,
>
> Thanks for reporting the problem.  Could you try applying below patch
> to your rc0 tree and rebuild QEMU, to see whether it fixes your problem?
>
> -----------------------------
> diff --git a/iothread.c b/iothread.c
> index 1b3463cb00..9f52270ae1 100644
> --- a/iothread.c
> +++ b/iothread.c
> @@ -31,11 +31,15 @@ typedef ObjectClass IOThreadClass;
>  #define IOTHREAD_CLASS(klass) \
>     OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)
>
> +#ifdef CONFIG_LINUX
>  /* Benchmark results from 2016 on NVMe SSD drives show max polling times 
> around
>   * 16-32 microseconds yield IOPS improvements for both iodepth=1 and 
> iodepth=32
>   * workloads.
>   */
>  #define IOTHREAD_POLL_MAX_NS_DEFAULT 32768ULL
> +#else
> +#define IOTHREAD_POLL_MAX_NS_DEFAULT 0ULL
> +#endif
>
>  static __thread IOThread *my_iothread;
>
> diff --git a/util/aio-win32.c b/util/aio-win32.c
> index d6d5e02f00..a67b00c6ad 100644
> --- a/util/aio-win32.c
> +++ b/util/aio-win32.c
> @@ -410,5 +410,7 @@ void aio_context_setup(AioContext *ctx)
>  void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
>                                   int64_t grow, int64_t shrink, Error **errp)
>  {
> -    error_setg(errp, "AioContext polling is not implemented on Windows");
> +    if (max_ns) {
> +        error_setg(errp, "AioContext polling is not implemented on Windows");
> +    }
>  }
> -----------------------------
>
> Thanks,
>
> --
> Peter Xu

Hi Peter,

Thanks, that patch does indeed fix the problem.

Best,
Howard