[PATCH for-5.0 v11 14/20] virtio-iommu: Handle reserved regions in the translation process

[Eric Auger]

When translating an address we need to check if it belongs to
a reserved virtual address range. If it does, there are 2 cases:

- it belongs to a RESERVED region: the guest should neither use
  this address in a MAP not instruct the end-point to DMA on
  them. We report an error

- It belongs to an MSI region: we bypass the translation.

Signed-off-by: Eric Auger <address@hidden>

---

v10 -> v11:
- directly use the reserved_regions properties array

v9 -> v10:
- in case of MSI region, we immediatly return
---
 hw/virtio/virtio-iommu.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index 1ce2218935..c5b202fab7 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -548,6 +548,7 @@ static IOMMUTLBEntry 
virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
     uint32_t sid, flags;
     bool bypass_allowed;
     bool found;
+    int i;
 
     interval.low = addr;
     interval.high = addr + 1;
@@ -580,6 +581,22 @@ static IOMMUTLBEntry 
virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
         goto unlock;
     }
 
+    for (i = 0; i < s->nb_reserved_regions; i++) {
+        if (interval.low >= s->reserved_regions[i].low &&
+            interval.low <= s->reserved_regions[i].high) {
+            switch (s->reserved_regions[i].type) {
+            case VIRTIO_IOMMU_RESV_MEM_T_MSI:
+                entry.perm = flag;
+                goto unlock;
+            case VIRTIO_IOMMU_RESV_MEM_T_RESERVED:
+            default:
+                virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_MAPPING,
+                                          0, sid, addr);
+            goto unlock;
+           }
+        }
+    }
+
     if (!ep->domain) {
         if (!bypass_allowed) {
             qemu_log_mask(LOG_GUEST_ERROR,
-- 
2.20.1