| Message ID | 20240327125433.248946-3-yi.l.liu@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Two enhancements to iommu_at[de]tach_device_pasid() | expand |
On Wed, Mar 27, 2024 at 05:54:33AM -0700, Yi Liu wrote: > There is no error handling now in __iommu_set_group_pasid(), it relies on > its caller to loop all the devices to undo the pasid attachment. This is > not self-contained and has unnecessary remove_dev_pasid() calls on the > devices that have not changed in the __iommu_set_group_pasid() call. this > results in unnecessary warnings by the underlying iommu drivers. Like the > Intel iommu driver, it would warn when there is no pasid attachment to > destroy in the remove_dev_pasid() callback. > > The ideal way is to handle the error within __iommu_set_group_pasid(). This > not only makes __iommu_set_group_pasid() self-contained, but also avoids > unnecessary warnings. > > Fixes: 16603704559c7a68 ("iommu: Add attach/detach_dev_pasid iommu interfaces") > Suggested-by: Jason Gunthorpe <jgg@nvidia.com> > Signed-off-by: Yi Liu <yi.l.liu@intel.com> > --- > drivers/iommu/iommu.c | 20 ++++++++++++++------ > 1 file changed, 14 insertions(+), 6 deletions(-) Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> This will need revising when we get to PASID replace, but good enough for now Thanks, Jason
On 2024/3/27 21:05, Jason Gunthorpe wrote: > On Wed, Mar 27, 2024 at 05:54:33AM -0700, Yi Liu wrote: >> There is no error handling now in __iommu_set_group_pasid(), it relies on >> its caller to loop all the devices to undo the pasid attachment. This is >> not self-contained and has unnecessary remove_dev_pasid() calls on the >> devices that have not changed in the __iommu_set_group_pasid() call. this >> results in unnecessary warnings by the underlying iommu drivers. Like the >> Intel iommu driver, it would warn when there is no pasid attachment to >> destroy in the remove_dev_pasid() callback. >> >> The ideal way is to handle the error within __iommu_set_group_pasid(). This >> not only makes __iommu_set_group_pasid() self-contained, but also avoids >> unnecessary warnings. >> >> Fixes: 16603704559c7a68 ("iommu: Add attach/detach_dev_pasid iommu interfaces") >> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> >> Signed-off-by: Yi Liu <yi.l.liu@intel.com> >> --- >> drivers/iommu/iommu.c | 20 ++++++++++++++------ >> 1 file changed, 14 insertions(+), 6 deletions(-) > > Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> > > This will need revising when we get to PASID replace, but good enough > for now yes, the rollback part would be revised a bit when coming to support PASID domain replacement. Already in the pending list, will send it out soon. :)
> From: Liu, Yi L <yi.l.liu@intel.com> > Sent: Wednesday, March 27, 2024 8:55 PM > + > +err_revert: > + last_gdev = device; > + for_each_group_device(group, device) { > + if (device == last_gdev) > + break; > + dev_iommu_ops(device->dev)->remove_dev_pasid(device- > >dev, > + pasid, domain); > + } break the long line into: ops = dev_iommu_ops(device->dev); ops->remove_dev_pasid(); otherwise it looks good to me: Reviewed-by: Kevin Tian <kevin.tian@intel.com>
On 2024/3/28 11:15, Tian, Kevin wrote: >> From: Liu, Yi L <yi.l.liu@intel.com> >> Sent: Wednesday, March 27, 2024 8:55 PM >> + >> +err_revert: >> + last_gdev = device; >> + for_each_group_device(group, device) { >> + if (device == last_gdev) >> + break; >> + dev_iommu_ops(device->dev)->remove_dev_pasid(device- >>> dev, >> + pasid, domain); >> + } > > break the long line into: > ops = dev_iommu_ops(device->dev); > ops->remove_dev_pasid(); got it. > otherwise it looks good to me: > > Reviewed-by: Kevin Tian <kevin.tian@intel.com>
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 681e916d285b..2a12c9c9e045 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3317,15 +3317,25 @@ EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed); static int __iommu_set_group_pasid(struct iommu_domain *domain, struct iommu_group *group, ioasid_t pasid) { - struct group_device *device; - int ret = 0; + struct group_device *device, *last_gdev; + int ret; for_each_group_device(group, device) { ret = domain->ops->set_dev_pasid(domain, device->dev, pasid); if (ret) - break; + goto err_revert; } + return 0; + +err_revert: + last_gdev = device; + for_each_group_device(group, device) { + if (device == last_gdev) + break; + dev_iommu_ops(device->dev)->remove_dev_pasid(device->dev, + pasid, domain); + } return ret; } @@ -3375,10 +3385,8 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, } ret = __iommu_set_group_pasid(domain, group, pasid); - if (ret) { - __iommu_remove_group_pasid(group, pasid, domain); + if (ret) xa_erase(&group->pasid_array, pasid); - } out_unlock: mutex_unlock(&group->mutex); return ret;
There is no error handling now in __iommu_set_group_pasid(), it relies on its caller to loop all the devices to undo the pasid attachment. This is not self-contained and has unnecessary remove_dev_pasid() calls on the devices that have not changed in the __iommu_set_group_pasid() call. this results in unnecessary warnings by the underlying iommu drivers. Like the Intel iommu driver, it would warn when there is no pasid attachment to destroy in the remove_dev_pasid() callback. The ideal way is to handle the error within __iommu_set_group_pasid(). This not only makes __iommu_set_group_pasid() self-contained, but also avoids unnecessary warnings. Fixes: 16603704559c7a68 ("iommu: Add attach/detach_dev_pasid iommu interfaces") Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> --- drivers/iommu/iommu.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)