Re: [PATCH v2 7/8] iommu/vt-d: Delete supervisor/kernel SVA

Jacob Pan
2022-03-29T17:39:01Z

Hi Kevin,

On Fri, 18 Mar 2022 06:16:58 +0000, "Tian, Kevin" <kevin.tian@intel.com>
wrote:

> > From: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > Sent: Tuesday, March 15, 2022 1:07 PM
> >
> > In-kernel DMA with PASID should use DMA API now, remove supervisor
> > PASID
> > SVA support. Remove special cases in bind mm and page request service.
> >
> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
>
> so you removed all the references to SVM_FLAG_SUPERVISOR_MODE
> but the definition is still kept in include/linux/intel-svm.h...
>
Good catch, will remove.

> > ---
> > drivers/iommu/intel/svm.c | 42 ++++++++-------------------------------
> > 1 file changed, 8 insertions(+), 34 deletions(-)
> >
> > diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> > index 2c53689da461..37d6218f173b 100644
> > --- a/drivers/iommu/intel/svm.c
> > +++ b/drivers/iommu/intel/svm.c
> > @@ -516,11 +516,10 @@ static void intel_svm_free_pasid(struct mm_struct
> > *mm)
> >
> > static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
> > struct device *dev,
> > - struct mm_struct *mm,
> > - unsigned int flags)
> > + struct mm_struct *mm)
> > {
> > struct device_domain_info *info = get_domain_info(dev);
> > - unsigned long iflags, sflags;
> > + unsigned long iflags, sflags = 0;
> > struct intel_svm_dev *sdev;
> > struct intel_svm *svm;
> > int ret = 0;
> > @@ -533,16 +532,13 @@ static struct iommu_sva
> > *intel_svm_bind_mm(struct intel_iommu *iommu,
> >
> > svm->pasid = mm->pasid;
> > svm->mm = mm;
> > - svm->flags = flags;
> > INIT_LIST_HEAD_RCU(&svm->devs);
> >
> > - if (!(flags & SVM_FLAG_SUPERVISOR_MODE)) {
> > - svm->notifier.ops = &intel_mmuops;
> > - ret = mmu_notifier_register(&svm->notifier,
> > mm);
> > - if (ret) {
> > - kfree(svm);
> > - return ERR_PTR(ret);
> > - }
> > + svm->notifier.ops = &intel_mmuops;
> > + ret = mmu_notifier_register(&svm->notifier, mm);
> > + if (ret) {
> > + kfree(svm);
> > + return ERR_PTR(ret);
> > }
> >
> > ret = pasid_private_add(svm->pasid, svm);
> > @@ -583,8 +579,6 @@ static struct iommu_sva *intel_svm_bind_mm(struct
> > intel_iommu *iommu,
> > }
> >
> > /* Setup the pasid table: */
> > - sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ?
> > - PASID_FLAG_SUPERVISOR_MODE : 0;
> > sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ?
> > PASID_FLAG_FL5LP : 0;
> > spin_lock_irqsave(&iommu->lock, iflags);
> > ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm-
> > >pasid,
> > @@ -957,7 +951,7 @@ static irqreturn_t prq_event_thread(int irq, void
> > *d)
> > * to unbind the mm while any page faults are
> > outstanding.
> > */
> > svm = pasid_private_find(req->pasid);
> > - if (IS_ERR_OR_NULL(svm) || (svm->flags &
> > SVM_FLAG_SUPERVISOR_MODE))
> > + if (IS_ERR_OR_NULL(svm))
> > goto bad_req;
> > }
> >
> > @@ -1011,29 +1005,9 @@ static irqreturn_t prq_event_thread(int irq, void
> > *d)
> > struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct
> > *mm, void *drvdata)
> > {
> > struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
> > - unsigned int flags = 0;
> > struct iommu_sva *sva;
> > int ret;
> >
> > - if (drvdata)
> > - flags = *(unsigned int *)drvdata;
> > -
> > - if (flags & SVM_FLAG_SUPERVISOR_MODE) {
> > - if (!ecap_srs(iommu->ecap)) {
> > - dev_err(dev, "%s: Supervisor PASID not
> > supported\n",
> > - iommu->name);
> > - return ERR_PTR(-EOPNOTSUPP);
> > - }
> > -
> > - if (mm) {
> > - dev_err(dev, "%s: Supervisor PASID with user
> > provided mm\n",
> > - iommu->name);
> > - return ERR_PTR(-EINVAL);
> > - }
> > -
> > - mm = &init_mm;
> > - }
> > -
> > mutex_lock(&pasid_mutex);
> > ret = intel_svm_alloc_pasid(dev, mm, flags);
> > if (ret) {
> > --
> > 2.25.1
>

Thanks,

Jacob