commit 50c8e11ac0672b726a2b3e2217cb32dc8416299f
author Frederic Barrat <fbarrat@linux.ibm.com> Fri Jan 28 13:15:02 2022 +0100
committer Cédric Le Goater <clg@kaod.org> Fri Jan 28 13:15:02 2022 +0100
tree 39bd75563dbbc6bcc19a59cb1980876187288301
parent e31ea5d89b613072e64b83f67e9763e9b149b87e

ppc/pnv: Fail DMA access if page permissions are not correct

If an iommu page has wrong permissions, an error message is displayed,
but the access is allowed, which is odd. This patch fixes it.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220121152350.381685-1-fbarrat@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/pci-host/pnv_phb3.c

diff --git a/hw/pci-host/pnv_phb3.c b/hw/pci-host/pnv_phb3.c
index 7fb35dc..a757f1a 100644
--- a/hw/pci-host/pnv_phb3.c
+++ b/hw/pci-host/pnv_phb3.c
@@ -816,18 +816,19 @@
         }
 
         /* We exit the loop with TCE being the final TCE */
-        tce_mask = ~((1ull << tce_shift) - 1);
-        tlb->iova = addr & tce_mask;
-        tlb->translated_addr = tce & tce_mask;
-        tlb->addr_mask = ~tce_mask;
-        tlb->perm = tce & 3;
         if ((is_write & !(tce & 2)) || ((!is_write) && !(tce & 1))) {
             phb3_error(phb, "TCE access fault at 0x%"PRIx64, taddr);
             phb3_error(phb, " xlate %"PRIx64":%c TVE=%"PRIx64, addr,
                        is_write ? 'W' : 'R', tve);
             phb3_error(phb, " tta=%"PRIx64" lev=%d tts=%d tps=%d",
                        tta, lev, tts, tps);
+            return;
         }
+        tce_mask = ~((1ull << tce_shift) - 1);
+        tlb->iova = addr & tce_mask;
+        tlb->translated_addr = tce & tce_mask;
+        tlb->addr_mask = ~tce_mask;
+        tlb->perm = tce & 3;
     }
 }
 

hw/pci-host/pnv_phb4.c

diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
index a78add7..ee56377 100644
--- a/hw/pci-host/pnv_phb4.c
+++ b/hw/pci-host/pnv_phb4.c
@@ -1291,18 +1291,19 @@
         }
 
         /* We exit the loop with TCE being the final TCE */
-        tce_mask = ~((1ull << tce_shift) - 1);
-        tlb->iova = addr & tce_mask;
-        tlb->translated_addr = tce & tce_mask;
-        tlb->addr_mask = ~tce_mask;
-        tlb->perm = tce & 3;
         if ((is_write & !(tce & 2)) || ((!is_write) && !(tce & 1))) {
             phb_error(ds->phb, "TCE access fault at 0x%"PRIx64, taddr);
             phb_error(ds->phb, " xlate %"PRIx64":%c TVE=%"PRIx64, addr,
                        is_write ? 'W' : 'R', tve);
             phb_error(ds->phb, " tta=%"PRIx64" lev=%d tts=%d tps=%d",
                        tta, lev, tts, tps);
+            return;
         }
+        tce_mask = ~((1ull << tce_shift) - 1);
+        tlb->iova = addr & tce_mask;
+        tlb->translated_addr = tce & tce_mask;
+        tlb->addr_mask = ~tce_mask;
+        tlb->perm = tce & 3;
     }
 }