>>> On 09.08.18 at 11:07, wrote: >>>> On 09.08.18 at 10:55, <paul.durr...@citrix.com> wrote: > >> From: Jan Beulich [mailto:jbeul...@suse.com] > >> Sent: 09 August 2018 09:47 > >> > >> >>> On 08.08.18 at 16:16, <paul.durr...@citrix.com> wrote: > >> > @@ -1046,6 +1090,16 @@ static int acquire_resource( > >> > xen_pfn_t gfn_list[ARRAY_SIZE(mfn_list)]; > >> > unsigned int i; > >> > > >> > + /* > >> > + * FIXME: Until foreign pages inserted into the P2M are properly > >> > + * reference counted, it is unsafe to allow mapping of > >> > + * non-caller-owned resource pages unless the caller is > >> > + * the hardware domain. > >> > + */ > >> > + if ( !(xmar.flags & XENMEM_rsrc_acq_caller_owned) && > >> > + !is_hardware_domain(currd) ) > >> > + return -EOPNOTSUPP; > >> > + > >> > >> Now that I look at this again - wouldn't this check better live ahead > >> of the main switch()? I find it odd, for example, that in this case the > >> grant table would still have got grown. > > > > This can't live ahead of the main switch because > > XENMEM_rsrc_acq_caller_owned is passed-out flag, not a passed-in one. > > Oh, right. Except that only arch_acquire_resource() could currently > set the flag, and hence from this patch's perspective it's not visible > that this is an "out" flag. I guess you mean to set the flag in > acquire_grant_table() or next to the call to it.
Rubbish - the flag is supposed to be clear here. I'm sorry for the noise. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
