James Carlson wrote: > David Edmondson writes: > >> * [EMAIL PROTECTED] [2008-01-14 07:34:17] >> >>>>> What type of change does IP do that causes Xen problems? >>>>> >>>> It byte-swaps fields in the headers. Given that the preference of the >>>> guest domain is to provide a read-only mapping to pages it loans to >>>> the IO domain, any attempt to modify packets is problematic. >>>> >>> And at a guess, we don't have a flag in the mblk/dblk that says the data >>> is read-only (or something similar)? >>> >> No, we don't have such a thing. >> > > Yes, we do. See esballoca() and desballoca(). The trick is to bump > the db_ref count and set DBLK_REFMIN in db_flags. >
Is there some documentation on how this is meant to work? There's no mention of this in dblk(9s) that I can see and there's only one use of DBLK_REFMIN in the kernel? That's not particularly attractive if that's what we intednd 3rd party developers to use. Darren _______________________________________________ networking-discuss mailing list [email protected]
