iommu/vt-d: Implement SVM_FLAG_PRIVATE_PASID to allocate unique PASIDs

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
David Woodhouse 2015-10-15 13:59:14 +01:00
parent 0204a49609
commit 569e4f7782
3 changed files with 16 additions and 2 deletions

View File

@ -285,11 +285,12 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
pasid_max = 1 << 20;
mutex_lock(&pasid_mutex);
if (pasid) {
if (pasid && !(flags & SVM_FLAG_PRIVATE_PASID)) {
int i;
idr_for_each_entry(&iommu->pasid_idr, svm, i) {
if (svm->mm != current->mm)
if (svm->mm != current->mm ||
(svm->flags & SVM_FLAG_PRIVATE_PASID))
continue;
if (svm->pasid >= pasid_max) {
@ -355,6 +356,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
svm->pasid = ret;
svm->notifier.ops = &intel_mmuops;
svm->mm = get_task_mm(current);
svm->flags = flags;
INIT_LIST_HEAD_RCU(&svm->devs);
ret = -ENOMEM;
if (!svm->mm || (ret = mmu_notifier_register(&svm->notifier, svm->mm))) {

View File

@ -489,6 +489,7 @@ struct intel_svm {
struct mmu_notifier notifier;
struct mm_struct *mm;
struct intel_iommu *iommu;
int flags;
int pasid;
struct list_head devs;
};

View File

@ -31,6 +31,17 @@ struct svm_dev_ops {
#define SVM_REQ_EXEC (1<<1)
#define SVM_REQ_PRIV (1<<0)
/*
* The SVM_FLAG_PRIVATE_PASID flag requests a PASID which is *not* the "main"
* PASID for the current process. Even if a PASID already exists, a new one
* will be allocated. And the PASID allocated with SVM_FLAG_PRIVATE_PASID
* will not be given to subsequent callers. This facility allows a driver to
* disambiguate between multiple device contexts which access the same MM,
* if there is no other way to do so. It should be used sparingly, if at all.
*/
#define SVM_FLAG_PRIVATE_PASID (1<<0)
/**
* intel_svm_bind_mm() - Bind the current process to a PASID
* @dev: Device to be granted acccess