Re: [PATCH v8 5/5] x86/tdx: Add Quote generation support

From: Dave Hansen
Date: Thu Jul 21 2022 - 12:49:11 EST


On 7/21/22 09:42, Sathyanarayanan Kuppuswamy wrote:
> On 7/21/22 9:08 AM, Dave Hansen wrote:
>> On 6/8/22 19:52, Kuppuswamy Sathyanarayanan wrote:
>>> For shared buffer allocation, alternatives like using the DMA API is
>>> also considered. Although it simpler to use, it is not preferred because
>>> dma_alloc_*() APIs require a valid bus device as argument, which would
>>> need converting the attestation driver into a platform device driver.
>>> This is unnecessary, and since the attestation driver does not do real
>>> DMA, there is no need to use real DMA APIs.
>> Let's actually try to walk through the requirements for the memory
>> allocation here.
>>
>> 1. The guest kernel needs to allocate some guest physical memory
>> for the attestation data buffer
> Physically contiguous memory.

Remind me how large the quote structures are.