> -----Original Message----- > From: George Dunlap [mailto:george.dun...@citrix.com] > Sent: Wednesday, February 10, 2016 8:25 PM > To: Wu, Feng <feng...@intel.com>; Jan Beulich <jbeul...@suse.com> > Cc: Andrew Cooper <andrew.coop...@citrix.com>; Dario Faggioli > <dario.faggi...@citrix.com>; George Dunlap <george.dun...@eu.citrix.com>; > Tian, Kevin <kevin.t...@intel.com>; xen-devel@lists.xen.org; Keir Fraser > <k...@xen.org> > Subject: Re: [PATCH v11 1/2] vmx: VT-d posted-interrupt core logic handling > > On 02/02/16 04:48, Wu, Feng wrote: > >>>>> --- a/xen/drivers/passthrough/vtd/iommu.c > >>>>> +++ b/xen/drivers/passthrough/vtd/iommu.c > >>>>> @@ -2293,6 +2293,8 @@ static int reassign_device_ownership( > >>>>> pdev->domain = target; > >>>>> } > >>>>> > >>>>> + vmx_pi_hooks_reassign(source, target); > >>>>> + > >>>>> return ret; > >>>>> } > >>>> > >>>> I think you need to clear source's hooks here, but target's need to > >>>> get set ahead of the actual assignment. > >>> > >>> I think this is the place where the device is moved from > >>> &source->arch.pdev_list to &target->arch.pdev_list, if that is the > >>> case, we should clear source and set target here, right? > >> > >> No - target needs to be ready to deal with events from the device > >> _before_ the device actually gets assigned to it. > > > > I still don't get your point. I still think this is the place where the > > device > > is being got assigned. Or maybe you can share more info about the > > place "_before_ the device actually gets assigned to it " ? > > What happens if a device generates a PI interrupt *immediately* after > domain_context_mapping(), but before calling vmx_pi_hooks_reassign()?
Sorry for the late response due to holiday. Good question. But I don't think that can happen, since we only support MSI/MSIx for PI, and MSI/MSIx is configured by guests after assign_device() gets called. Thanks, Feng > > -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
