Subject: Re: [PATCH 11/12] powerpc/pseries/svm: Force SWIOTLB for secure guests

From: Christoph Hellwig <[email-masked]>
Date: Tue, 21 May 2019 07:15:07 +0200

> diff --git a/arch/powerpc/include/asm/mem_encrypt.h b/arch/powerpc/include/asm/mem_encrypt.h
> new file mode 100644
> index 000000000000..45d5e4d0e6e0
> --- /dev/null
> +++ b/arch/powerpc/include/asm/mem_encrypt.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * SVM helper functions
> + *
> + * Copyright 2019 IBM Corporation
> + */
> +
> +#ifndef _ASM_POWERPC_MEM_ENCRYPT_H
> +#define _ASM_POWERPC_MEM_ENCRYPT_H
> +
> +#define sme_me_mask	0ULL
> +
> +static inline bool sme_active(void) { return false; }
> +static inline bool sev_active(void) { return false; }
> +
> +int set_memory_encrypted(unsigned long addr, int numpages);
> +int set_memory_decrypted(unsigned long addr, int numpages);
> +
> +#endif /* _ASM_POWERPC_MEM_ENCRYPT_H */

S/390 seems to be adding a stub header just like this.  Can you please
clean up the Kconfig and generic headers bits for memory encryption so
that we don't need all this boilerplate code?

>  config PPC_SVM
>  	bool "Secure virtual machine (SVM) support for POWER"
>  	depends on PPC_PSERIES
> +	select SWIOTLB
> +	select ARCH_HAS_MEM_ENCRYPT
>  	default n

n is the default default, no need to explictly specify it.