Hi Zixuan,
On 9/21/21 5:58 AM, Zixuan Wang wrote:
> On Mon, Sep 20, 2021 at 6:26 PM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>>
>> On 27/08/21 05:12, Zixuan Wang wrote:
>>> +
>>> +/*
>>> + * The UEFI spec and EDK2 reference implementation both define EFI_GUID as
>>> + * struct { u32 a; u16; b; u16 c; u8 d[8]; }; and so the implied alignment
>>> + * is 32 bits not 8 bits like our guid_t. In some cases (i.e., on 32-bit ARM),
>>> + * this means that firmware services invoked by the kernel may assume that
>>> + * efi_guid_t* arguments are 32-bit aligned, and use memory accessors that
>>> + * do not tolerate misalignment. So let's set the minimum alignment to 32 bits.
>>
>> Here you're not doing that though.
>>
>> Paolo
>
> Hi Paolo,
>
> Indeed, I checked the original Linux code [1] and it has the alignment.
>
> This patch is from Varad's patch set [2]. I can update this code in
> the next version if Varad is OK with it.
>
Please feel free to modify the patch in the next revision. The alignment
indeed does not make sense here.
Thanks,
Varad
> I just finished my Google internship and lost my access to the Google
> email, so I'm replying with my personal email.
>
> [1] https://elixir.bootlin.com/linux/v5.14/source/include/linux/efi.h#L73
> [2] https://lore.kernel.org/kvm/20210819113400.26516-1-varad.gautam@xxxxxxxx/
>
> Best regards,
> Zixuan
>
