Hi Baolu,
Well received, all comments accepted. thanks.
Regards,
Yi Liu
> From: Lu Baolu <baolu...@linux.intel.com>
> Sent: Wednesday, December 23, 2020 6:10 PM
>
> Hi Yi,
>
> On 2020/12/23 14:27, Liu Yi L wrote:
> > iommu_flush_dev_iotlb() is called to invalidate caches on device. It only
> > loops the devices which are full-attached to the domain. For sub-devices,
> > this is ineffective. This results in invalid caching entries left on the
> > device. Fix it by adding loop for subdevices as well. Also, the domain->
> > has_iotlb_device needs to be updated when attaching to subdevices.
> >
> > Fixes: 67b8e02b5e761 ("iommu/vt-d: Aux-domain specific domain
> attach/detach")
> > Signed-off-by: Liu Yi L <yi.l....@intel.com>
> > ---
> > drivers/iommu/intel/iommu.c | 63 +++++++++++++++++++++++++++---------
> -
> > 1 file changed, 47 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > index acfe0a5b955e..e97c5ac1d7fc 100644
> > --- a/drivers/iommu/intel/iommu.c
> > +++ b/drivers/iommu/intel/iommu.c
> > @@ -726,6 +726,8 @@ static int domain_update_device_node(struct
> dmar_domain *domain)
> > return nid;
> > }
> >
> > +static void domain_update_iotlb(struct dmar_domain *domain);
> > +
> > /* Some capabilities may be different across iommus */
> > static void domain_update_iommu_cap(struct dmar_domain *domain)
> > {
> > @@ -739,6 +741,8 @@ static void domain_update_iommu_cap(struct
> dmar_domain *domain)
> > */
> > if (domain->nid == NUMA_NO_NODE)
> > domain->nid = domain_update_device_node(domain);
> > +
> > + domain_update_iotlb(domain);
> > }
> >
> > struct context_entry *iommu_context_addr(struct intel_iommu *iommu,
> u8 bus,
> > @@ -1459,6 +1463,18 @@ iommu_support_dev_iotlb (struct dmar_domain
> *domain, struct intel_iommu *iommu,
> > return NULL;
> > }
> >
> > +static bool dev_iotlb_enabled(struct device_domain_info *info)
> > +{
> > + struct pci_dev *pdev;
> > +
> > + if (!info->dev || !dev_is_pci(info->dev))
> > + return false;
> > +
> > + pdev = to_pci_dev(info->dev);
> > +
> > + return !!pdev->ats_enabled;
> > +}
>
> I know this is just separated from below function. But isn't "(info &&
> info->ats_enabled)" is enough?
>
> > +
> > static void domain_update_iotlb(struct dmar_domain *domain)
> > {
> > struct device_domain_info *info;
> > @@ -1466,17 +1482,20 @@ static void domain_update_iotlb(struct
> dmar_domain *domain)
> >
> > assert_spin_locked(&device_domain_lock);
> >
> > - list_for_each_entry(info, &domain->devices, link) {
> > - struct pci_dev *pdev;
> > -
> > - if (!info->dev || !dev_is_pci(info->dev))
> > - continue;
> > -
> > - pdev = to_pci_dev(info->dev);
> > - if (pdev->ats_enabled) {
> > + list_for_each_entry(info, &domain->devices, link)
> > + if (dev_iotlb_enabled(info)) {
> > has_iotlb_device = true;
> > break;
> > }
> > +
> > + if (!has_iotlb_device) {
> > + struct subdev_domain_info *sinfo;
> > +
> > + list_for_each_entry(sinfo, &domain->subdevices, link_domain)
> > + if (dev_iotlb_enabled(get_domain_info(sinfo->pdev)))
> {
>
> Please make the code easier for reading by:
>
> info = get_domain_info(sinfo->pdev);
> if (dev_iotlb_enabled(info))
> ....
>
> Best regards,
> baolu
>
> > + has_iotlb_device = true;
> > + break;
> > + }
> > }
> >
> > domain->has_iotlb_device = has_iotlb_device;
> > @@ -1557,25 +1576,37 @@ static void iommu_disable_dev_iotlb(struct
> device_domain_info *info)
> > #endif
> > }
> >
> > +static void __iommu_flush_dev_iotlb(struct device_domain_info *info,
> > + u64 addr, unsigned int mask)
> > +{
> > + u16 sid, qdep;
> > +
> > + if (!info || !info->ats_enabled)
> > + return;
> > +
> > + sid = info->bus << 8 | info->devfn;
> > + qdep = info->ats_qdep;
> > + qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
> > + qdep, addr, mask);
> > +}
> > +
> > static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
> > u64 addr, unsigned mask)
> > {
> > - u16 sid, qdep;
> > unsigned long flags;
> > struct device_domain_info *info;
> > + struct subdev_domain_info *sinfo;
> >
> > if (!domain->has_iotlb_device)
> > return;
> >
> > spin_lock_irqsave(&device_domain_lock, flags);
> > - list_for_each_entry(info, &domain->devices, link) {
> > - if (!info->ats_enabled)
> > - continue;
> > + list_for_each_entry(info, &domain->devices, link)
> > + __iommu_flush_dev_iotlb(info, addr, mask);
> >
> > - sid = info->bus << 8 | info->devfn;
> > - qdep = info->ats_qdep;
> > - qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
> > - qdep, addr, mask);
> > + list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
> > + __iommu_flush_dev_iotlb(get_domain_info(sinfo->pdev),
> > + addr, mask);
> > }
> > spin_unlock_irqrestore(&device_domain_lock, flags);
> > }
> >
