Re: [PATCH v9 12/13] iommu/amd: Clear out the GV flag when handle deferred domain attach

Joerg Roedel
2017-08-04T13:18:08Z

On Fri, Aug 04, 2017 at 09:13:20PM +0800, Baoquan He wrote:
> On 08/04/17 at 02:30pm, Joerg Roedel wrote:
> > On Tue, Aug 01, 2017 at 07:37:28PM +0800, Baoquan He wrote:
> > > @@ -2466,11 +2472,21 @@ static struct protection_domain *get_domain(struct device *dev)
> > > return ERR_PTR(-EINVAL);
> > >
> > > domain = get_dev_data(dev)->domain;
> > > - if (domain == NULL && get_dev_data(dev)->defer_attach) {
> > > + if (domain == NULL && dev_data->defer_attach) {
> > > + u16 alias = amd_iommu_alias_table[dev_data->devid];
> > > get_dev_data(dev)->defer_attach = false;
> > > io_domain = iommu_get_domain_for_dev(dev);
> > > domain = to_pdomain(io_domain);
> > > attach_device(dev, domain);
> > > + /*
> > > + * If the deferred attached domain is not v2, should clear out
> > > + * the old GV flag.
> > > + */
> > > + if (!(domain->flags & PD_IOMMUV2_MASK)) {
> > > + clear_dte_flag_gv(dev_data->devid);
> > > + if (alias != dev_data->devid)
> > > + clear_dte_flag_gv(dev_data->devid);
> >
> > Hmm, thinking more about it, I am not sure what the IOMMU responds to
> > PRI/PASID prefixes if the GV flag is 0.
> >
> > But until we know it causes problems we should just disable the bit
> > while doing the copy in the previous patch and avoid any special
> > handling like done here.
>
> So just drop this patch, right? Will do if I got it right. Thanks.

Yes, and clear the GV flag in the previous patch too.