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Date:   Sat, 16 Jul 2022 22:08:09 -0700
From:   "H. Peter Anvin" <hpa@zytor.com>
To:     Brijesh Singh <brijesh.singh@amd.com>,
        Thomas Gleixner <tglx@linutronix.de>, x86@kernel.org,
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Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_v12_29/46=5D_x86/boot=3A_Add_Co?= =?US-ASCII?Q?nfidential_Computing_type_to_setup=5Fdata?=
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On April 7, 2022 7:57:22 AM PDT, Brijesh Singh <brijesh=2Esingh@amd=2Ecom> =
wrote:
>
>
>On 4/6/22 16:19, Thomas Gleixner wrote:
>> On Mon, Mar 07 2022 at 15:33, Brijesh Singh wrote:
>>>  =20
>>> +/*
>>> + * AMD SEV Confidential computing blob structure=2E The structure is
>>> + * defined in OVMF UEFI firmware header:
>>> + * https://github=2Ecom/tianocore/edk2/blob/master/OvmfPkg/Include/Gu=
id/ConfidentialComputingSevSnpBlob=2Eh
>>> + */
>>> +#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;
>>> +};
>>=20
>> Shouldn't this be packed?
>>=20
>
>Yep, to avoid any additional compiler alignment we should pack it=2E
>
>thanks

It shouldn't be *necessary*, any more than it is necessary for kernel-user=
 space structures, since EFI is a C-based ABI=2E On x86 it doesn't hurt, ei=
ther, though, so might as well=2E