[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Minios-devel] [UNIKRAFT PATCH 6/6] plat/xen: Add grant table support for Xen (x86_64)
Wei Liu <wei.liu2@xxxxxxxxxx> writes: > On Wed, Jun 27, 2018 at 03:49:21PM +0200, Yuri Volchkov wrote: >> > +grant_ref_t gnttab_grant_access(domid_t domid, unsigned long pfn, >> > + int readonly) >> Is it supposed to be a mfn, not pfn? >> >> > +{ >> > + grant_ref_t gref; >> > + >> > + gref = get_free_entry(); >> > + gnttab.table[gref].frame = pfn; >> > + gnttab.table[gref].domid = domid; >> > + wmb(); >> Why the barrier is here not after setting the readonly flag? MiniOS and >> Linux are doing the same, so I assume that is the right way. Maybe you >> could enlighten me? :) >> > > Because the purpose is to make sure the write to the flags field happens > *after* the write to frame and domid fields. I.e. the change of the flag > will be visible only after the changes to the other fields are visible. > > There are probably some paring rmb() in the code, but I haven't > looked... > > Wei. That makes sense. Thank you! -- Yuri Volchkov Software Specialist NEC Europe Ltd Kurfürsten-Anlage 36 D-69115 Heidelberg _______________________________________________ Minios-devel mailing list Minios-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/minios-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |