Re: [PATCH v12 29/46] x86/boot: Add Confidential Computing type to setup_data

[H. Peter Anvin]

On April 7, 2022 7:57:22 AM PDT, Brijesh Singh <brijesh.singh@xxxxxxx> wrote:
>
>
>On 4/6/22 16:19, Thomas Gleixner wrote:
>> On Mon, Mar 07 2022 at 15:33, Brijesh Singh wrote:
>>>   
>>> +/*
>>> + * AMD SEV Confidential computing blob structure. The structure is
>>> + * defined in OVMF UEFI firmware header:
>>> + * https://github.com/tianocore/edk2/blob/master/OvmfPkg/Include/Guid/ConfidentialComputingSevSnpBlob.h
>>> + */
>>> +#define CC_BLOB_SEV_HDR_MAGIC	0x45444d41
>>> +struct cc_blob_sev_info {
>>> +	u32 magic;
>>> +	u16 version;
>>> +	u16 reserved;
>>> +	u64 secrets_phys;
>>> +	u32 secrets_len;
>>> +	u32 rsvd1;
>>> +	u64 cpuid_phys;
>>> +	u32 cpuid_len;
>>> +	u32 rsvd2;
>>> +};
>> 
>> Shouldn't this be packed?
>> 
>
>Yep, to avoid any additional compiler alignment we should pack it.
>
>thanks

It shouldn't be *necessary*, any more than it is necessary for kernel-user space structures, since EFI is a C-based ABI. On x86 it doesn't hurt, either, though, so might as well.