Hi Jan,
On 29/06/2020 09:28, Jan Beulich wrote:
On 27.06.2020 11:55, Julien Grall wrote:
From: Julien Grall <jgr...@amazon.com>
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.
The added padding doesn't change the alignment. It's sizeof() which
gets corrected this way.
I will update the commit message.
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
Nit: ... will be the same ...
Ok.
the all architectures. The potential breakage of compatibility is ought
Nit: Drop "is".
Ok.
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.
Why is the other adjustment fine to make due to still being tech
preview, but this one wouldn't be for the same reason?
This is mostly a left-over of the previous message. Although, I am not
really inclined to address this myself any time soon.
Cheers,
--
Julien Grall
