Re: [RFC v2 1/4] tls: add macros for coroutine-safe TLS variables

[Florian Weimer]

* Stefan Hajnoczi:

> +#elif defined(__x86_64__)
> +#define QEMU_CO_TLS_ADDR(ret, var)                              \
> +    asm volatile("rdfsbase %0\n\t"                              \
> +                 "lea "#var"@tpoff(%0), %0" : "=r"(ret))
> +#endif

RDFSBASE needs quite recent kernels.  I think you should use

  movq %%fs:0, %0

instead, which is equivalent for the x86-64 psABI.

Thanks,
Florian