iommu/vt-d: Reject unsupported page request modes

When supervisor/privilige mode SVM is used, we bind init_mm.pgd with
a supervisor PASID. There should not be any page fault for init_mm.
Execution request with DMA read is also not supported.

This patch checks PRQ descriptor for both unsupported configurations,
reject them both with invalid responses.

Fixes: 1c4f88b7f1f92 ("iommu/vt-d: Shared virtual address in scalable mode")
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Link: https://lore.kernel.org/r/1614680040-1989-4-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 574a7e6..4627437 100644 (file)
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -920,7 +920,17 @@ static irqreturn_t prq_event_thread(int irq, void *d)
                               ((unsigned long long *)req)[1]);
                        goto no_pasid;
                }
-
+               /* We shall not receive page request for supervisor SVM */
+               if (req->pm_req && (req->rd_req | req->wr_req)) {
+                       pr_err("Unexpected page request in Privilege Mode");
+                       /* No need to find the matching sdev as for bad_req */
+                       goto no_pasid;
+               }
+               /* DMA read with exec requeset is not supported. */
+               if (req->exe_req && req->rd_req) {
+                       pr_err("Execution request not supported\n");
+                       goto no_pasid;
+               }
                if (!svm || svm->pasid != req->pasid) {
                        rcu_read_lock();
                        svm = ioasid_find(NULL, req->pasid, NULL);