| Message ID | 20220701214455.14992-4-nicolinc@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | cover-letter: Simplify vfio_iommu_type1 attach/detach routine | expand |
On Fri, Jul 01, 2022 at 02:44:53PM -0700, Nicolin Chen wrote: > The domain->ops validation was added, as a precaution, for mixed-driver > systems. > > Per Robin's remarks, > * While bus_set_iommu() still exists, the core code prevents multiple > drivers from registering, so we can't really run into a situation of > having a mixed-driver system: > https://lore.kernel.org/kvm/6e1280c5-4b22-ebb3-3912-6c72bc169982@arm.com/ > > * And there's plenty more significant problems than this to fix; in future > when many can be permitted, we will rely on the IOMMU core code to check > the domain->ops: > https://lore.kernel.org/kvm/6575de6d-94ba-c427-5b1e-967750ddff23@arm.com/ > > So remove the check in VFIO for simplicity. > > Reviewed-by: Kevin Tian <kevin.tian@intel.com> > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> > --- > drivers/vfio/vfio_iommu_type1.c | 32 +++++++++++--------------------- > 1 file changed, 11 insertions(+), 21 deletions(-) Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Jason
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 7530f0d727e5..5992ee2345a0 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -2280,29 +2280,19 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, domain->domain->ops->enforce_cache_coherency( domain->domain); - /* - * Try to match an existing compatible domain. We don't want to - * preclude an IOMMU driver supporting multiple bus_types and being - * able to include different bus_types in the same IOMMU domain, so - * we test whether the domains use the same iommu_ops rather than - * testing if they're on the same bus_type. - */ + /* Try to match an existing compatible domain */ list_for_each_entry(d, &iommu->domain_list, next) { - if (d->domain->ops == domain->domain->ops) { - iommu_detach_group(domain->domain, group->iommu_group); - if (!iommu_attach_group(d->domain, - group->iommu_group)) { - list_add(&group->next, &d->group_list); - iommu_domain_free(domain->domain); - kfree(domain); - goto done; - } - - ret = iommu_attach_group(domain->domain, - group->iommu_group); - if (ret) - goto out_domain; + iommu_detach_group(domain->domain, group->iommu_group); + if (!iommu_attach_group(d->domain, group->iommu_group)) { + list_add(&group->next, &d->group_list); + iommu_domain_free(domain->domain); + kfree(domain); + goto done; } + + ret = iommu_attach_group(domain->domain, group->iommu_group); + if (ret) + goto out_domain; } vfio_test_domain_fgsp(domain);