[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v4 for-4.14 2/2] pvcalls: Document correctly and explicitely the padding for all arches
On 27.06.20 11:55, Julien Grall wrote: From: Julien Grall <jgrall@xxxxxxxxxx> The specification of pvcalls suggests there is padding for 32-bit x86 at the end of most the structure. However, they are not described in in the public header. Because of that all the structures would be 32-bit aligned and not 64-bit aligned for 32-bit x86. For all the other architectures supported (Arm and 64-bit x86), the structure are aligned to 64-bit because they contain uint64_t field. Therefore all the structures contain implicit padding. Given the specification is authoriitative, the padding will the same for s/authoriitative/authoritative/ the all architectures. The potential breakage of compatibility is ought s/the// to be fine as pvcalls is still a tech preview. As an aside, the padding sadly cannot be mandated to be 0 as they are already present. So it is not going to be possible to use the padding for extending a command in the future. Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx> With above fixed: Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Juergen
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