Re: memop struct packing, 32/64 bits

[Keir Fraser <keir.xen@gmail.com>]

On 19/01/2012 22:00, "Keir Fraser" <keir.xen@gmail.com> wrote:

>> Would like public headers to not be gcc specific. The toolstack is a more
>> specific special case, it contains lots of gcc-isms anyway. Hence its
>> sysctl/domctl hypercalls are allowed more leeway.
>> 
>> Frankly, rather than hauling the mem_event toolstack operations out of
>> domctl, you might be better just fixing the coarse-grained locking at least
>> for the particular commands you care about. The big domctl lock is not
>> needed for a quite a few of those domctl operations.
> 
> As an alternative, you could declare a tools-only section for
> public/memory.h. See public/hvm/hvm_op.h for example, which therefore gets
> to use uint64_aligned_t in those sections.

Also, if you are adding toolstack commands to an existing general-purpose
hypercall, wrapping it in defined(__XEN_TOOLS__) is useful documentation.

 -- Keir

> If your struct is for general consumption by any guest then you're SOL and
> have to do it the hard way.