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

[Thiago Jung Bauermann <bauerman@linux.ibm.com>]

Hello Christoph,

Thanks for reviewing the patch!

Christoph Hellwig <hch@lst.de> writes:

>> 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?

Yes, that's a good idea. Will do.

>>  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.

Indeed. Changed for the next version.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center