> >>> - unsigned long frame; /* Frame being granted. */
> >>> + domid_t trans_dom;
> >>> + uint32_t trans_gref;
> >>> + uint32_t frame; /* Frame being granted. */
> >>
> >> Using a uint32_t for a frame number is not valid anymore after the recent
> >> sparse physical memory support changes (and I don't think it would have
> >> been valid on ia64 even before).
Yes, agreed, I'll put it back to unsigned long.
> >What about the 'uint32_t frame' in grant_entry_v2_t -- I'm surprised you
> >didn't mention that also? It's most critical we get the sizing of that
>
> Oops, that one slipped my attention.
>
> >correct, while we're rev'ing a public interface. Given the definition of
> >__spacer[], it looks like there's space to have a full 'uint64_t frame' in
> >that structure too, no problem. A bit of field reordering might be needed to
> >make everything align naturally yet compactly, is all, I think?
> Agreed. Not sure though whether uintXX_t is the right thing to use -
> after all we have xen_pfn_t for exactly this purpose.
Maybe. xen_pfn_t probably would be the right type, but, again, it's
not 32/64 clean, which means it'd need some compat stuff. Not
impossible, but kind of annoying.
Would something like this be acceptable?
struct grant_entry_v2 {
grant_entry_header_t hdr;
union {
/*
* The frame to which we are granting access. This field has
* the same meaning as the grant_entry_v1 field of the same
* name.
*/
struct {
uint32_t pad0;
uint64_t frame;
} __attribute__((packed));
/*
* If the grant type is GTF_grant_access and GTF_sub_page is
* set, @domid is allowed to access bytes
* [@page_off,@page_off+@length) in frame @frame.
*/
struct {
uint16_t page_off;
uint16_t length;
uint64_t frame;
} __attribute__((packed)) sub_page;
/*
* If the grant is GTF_transitive, @domid is allowed to use
* the grant @gref in domain @trans_domid, as if it was the
* local domain. Obviously, the transitive access must be
* compatible with the original grant.
*
* The current version of Xen does not allow transitive grants
* to be mapped.
*/
struct {
domid_t trans_domid;
uint16_t pad0;
grant_ref_t gref;
} transitive;
uint32_t __spacer[3]; /* Pad to a power of two */
};
};
typedef struct grant_entry_v2 grant_entry_v2_t;
The __attribute__((packed))s are very much not a thing of beauty, but
it's at least fairly self-contained.
Steven.
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