Re: [PATCH v2 03/13] powerpc/prom_init: Add the ESM call to prom_init

[Thiago Jung Bauermann]

Alexey Kardashevskiy <aik@xxxxxxxxx> writes:

> On 19/07/2019 07:28, Thiago Jung Bauermann wrote:
>>
>> Hello Segher,
>>
>> Thanks for your review and suggestions!
>>
>> Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx> writes:
>>
>>> (Sorry to hijack your reply).
>>>
>>> On Thu, Jul 18, 2019 at 06:11:48PM +1000, Alexey Kardashevskiy wrote:
>>>> On 13/07/2019 16:00, Thiago Jung Bauermann wrote:
>>>>> From: Ram Pai <linuxram@xxxxxxxxxx>
>>>>> +static int enter_secure_mode(unsigned long kbase, unsigned long fdt)
>>>>> +{
>>>>> +	register uint64_t func asm("r3") = UV_ESM;
>>>>> +	register uint64_t arg1 asm("r4") = (uint64_t)kbase;
>>>>> +	register uint64_t arg2 asm("r5") = (uint64_t)fdt;
>>>>
>>>> What does UV do with kbase and fdt precisely? Few words in the commit
>>>> log will do.
>
>
> What about this one? :)

Sorry, I don't have an elaborate answer yet. The non-elaborate answer is
that the ultravisor uses the kbase and fdt as part of integrity checking
of the secure guest.

--
Thiago Jung Bauermann
IBM Linux Technology Center