Re: [PATCH v7 06/20] x86/virt/tdx: Shut down TDX module in case of error

[Peter Zijlstra]

On Mon, Nov 21, 2022 at 01:26:28PM +1300, Kai Huang wrote:

> +/*
> + * Data structure to make SEAMCALL on multiple CPUs concurrently.
> + * @err is set to -EFAULT when SEAMCALL fails on any cpu.
> + */
> +struct seamcall_ctx {
> +	u64 fn;
> +	u64 rcx;
> +	u64 rdx;
> +	u64 r8;
> +	u64 r9;
> +	atomic_t err;
> +};

> @@ -166,6 +180,25 @@ static int __always_unused seamcall(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9,
>  	}
>  }
>  
> +static void seamcall_smp_call_function(void *data)
> +{
> +	struct seamcall_ctx *sc = data;
> +	int ret;
> +
> +	ret = seamcall(sc->fn, sc->rcx, sc->rdx, sc->r8, sc->r9, NULL, NULL);
> +	if (ret)
> +		atomic_set(&sc->err, -EFAULT);
> +}

Can someone explain me this usage of atomic_t, please?