From: Frederic Barrat <fbarrat@linux.ibm.com>
Date: Fri, 28 Jan 2022 12:15:02 +0000 (+0100)
Subject: ppc/pnv: Fail DMA access if page permissions are not correct
X-Git-Tag: qemu-xen-4.17.0-rc4~114^2~37
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=50c8e11ac0672b726a2b3e2217cb32dc8416299f;p=qemu-xen.git

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>
---

diff --git a/hw/pci-host/pnv_phb3.c b/hw/pci-host/pnv_phb3.c
index 7fb35dc031..a757f1a58e 100644
--- a/hw/pci-host/pnv_phb3.c
+++ b/hw/pci-host/pnv_phb3.c
@@ -816,18 +816,19 @@ static void pnv_phb3_translate_tve(PnvPhb3DMASpace *ds, hwaddr addr,
         }
 
         /* 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;
     }
 }
 
diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
index a78add75b0..ee56377c02 100644
--- a/hw/pci-host/pnv_phb4.c
+++ b/hw/pci-host/pnv_phb4.c
@@ -1291,18 +1291,19 @@ static void pnv_phb4_translate_tve(PnvPhb4DMASpace *ds, hwaddr addr,
         }
 
         /* 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;
     }
 }