On 2/19/21 5:31 AM, Jacob Pan wrote:
Page requests are originated from the user page fault. Therefore, we shall set FAULT_FLAG_USER.FAULT_FLAG_REMOTE indicates that we are walking an mm which is not guaranteed to be the same as the current->mm and should not be subject to protection key enforcement. Therefore, we should set FAULT_FLAG_REMOTE to avoid faults when both SVM and PKEY are used. References: commit 1b2ee1266ea6 ("mm/core: Do not enforce PKEY permissions on remote mm access") Reviewed-by: Raj Ashok <[email protected]> Signed-off-by: Jacob Pan <[email protected]>
Acked-by: Lu Baolu <[email protected]> Best regards, baolu
--- drivers/iommu/intel/svm.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index ff7ae7cc17d5..7bfd20a24a60 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -1086,6 +1086,7 @@ static irqreturn_t prq_event_thread(int irq, void *d) struct intel_iommu *iommu = d; struct intel_svm *svm = NULL; int head, tail, handled = 0; + unsigned int flags = 0;/* Clear PPR bit before reading head/tail registers, to* ensure that we get a new interrupt if needed. */ @@ -1186,9 +1187,11 @@ static irqreturn_t prq_event_thread(int irq, void *d) if (access_error(vma, req)) goto invalid;- ret = handle_mm_fault(vma, address,- req->wr_req ? FAULT_FLAG_WRITE : 0, - NULL); + flags = FAULT_FLAG_USER | FAULT_FLAG_REMOTE; + if (req->wr_req) + flags |= FAULT_FLAG_WRITE; + + ret = handle_mm_fault(vma, address, flags, NULL); if (ret & VM_FAULT_ERROR) goto invalid;
