Re: [PATCH v3] tcg: Fix execution on Apple Silicon

[Richard Henderson]

On 1/12/21 5:28 PM, Roman Bolshakov wrote:
> @@ -1083,6 +1083,12 @@ static bool alloc_code_gen_buffer_anon(size_t size, 
> int prot,
>  {
>      void *buf;
>  
> +#if defined(MAC_OS_VERSION_11_0) && \
> +    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_VERSION_11_0
> +    if (__builtin_available(macOS 11.0, *)) {
> +        flags |= MAP_JIT;
> +    }
> +#endif

This hunk should be in alloc_code_gen_buffer, where we do the other flags
manipulation.

I'll drop this hunk and apply the rest, which is exclusively related to
toggling the jit bit.

> --- a/util/osdep.c
> +++ b/util/osdep.c
> @@ -606,3 +606,23 @@ writev(int fd, const struct iovec *iov, int iov_cnt)
>      return readv_writev(fd, iov, iov_cnt, true);
>  }
>  #endif
> +
> +#if defined(MAC_OS_VERSION_11_0) && \
> +    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_VERSION_11_0
> +void qemu_thread_jit_execute(void)
> +{
> +    if (__builtin_available(macOS 11.0, *)) {
> +        pthread_jit_write_protect_np(true);
> +    }
> +}
> +
> +void qemu_thread_jit_write(void)
> +{
> +    if (__builtin_available(macOS 11.0, *)) {
> +        pthread_jit_write_protect_np(false);
> +    }
> +}
> +#else
> +void qemu_thread_jit_write(void) {}
> +void qemu_thread_jit_execute(void) {}
> +#endif

I will move these inline in osdep.h, because it's either (1) a single function
call or (2) a nop.


r~