On 06/03/2025 7:09 am, Jürgen Groß wrote: > On 05.03.25 23:57, Andrew Cooper wrote: >> On 05/03/2025 8:52 am, Juergen Gross wrote: >>> The description of the Xenstore INTRODUCE command is still referencing >>> xend. Fix that. >>> >>> While at it, make clear that the Xenstore implementation is allowed >>> to ignore the specified gfn and use the Xenstore reserved grant id >>> GNTTAB_RESERVED_XENSTORE instead. >>> >>> Signed-off-by: Juergen Gross <jgr...@suse.com> >>> --- >>> docs/misc/xenstore.txt | 6 +++++- >>> 1 file changed, 5 insertions(+), 1 deletion(-) >>> >>> diff --git a/docs/misc/xenstore.txt b/docs/misc/xenstore.txt >>> index 38015835b1..d894d24d11 100644 >>> --- a/docs/misc/xenstore.txt >>> +++ b/docs/misc/xenstore.txt >>> @@ -286,7 +286,7 @@ TRANSACTION_END F| >>> INTRODUCE <domid>|<gfn>|<evtchn>|? >>> Notifies xenstored to communicate with this domain. >>> - INTRODUCE is currently only used by xend (during domain >>> + INTRODUCE is currently only used by xen tools (during domain >>> startup and various forms of restore and resume), and >>> xenstored prevents its use other than by dom0. >>> @@ -299,6 +299,10 @@ INTRODUCE <domid>|<gfn>|<evtchn>|? >>> for example passing a high-bit-set 32-bit gfn as an unsigned >>> decimal will attempt to use 0x7fffffff instead (!). >>> + Xenstored might ignore the <gfn> value and use the reserved >>> + grant table entry GNTTAB_RESERVED_XENSTORE instead for mapping >>> + the Xenstore interface page of the guest. >> >> I'd suggest making a stronger statement than this. >> >> --- >> The <gfn> field is used by xenstoreds which use foreign mapping to >> access the ring page. >> >> Alternatively, Grant 1 (GNTTAB_RESERVED_XENSTORE) is reserved for the >> same purpose, and is populated by the domain builder on behalf of the >> guest. This mechanism is preferred because reduces the permissions that >> xenstored needs in order to function. >> >> Both <gfn> and Grant 1 need to agree, because implementations of >> xenstored will use one and ignore the other. > > Fine with me.
Are you happy for me to adjust on commit, or do you want a v2 sending out? ~Andrew
