memory: add address_space_access_valid
The old-style IOMMU lets you check whether an access is valid in a
given DMAContext. There is no equivalent for AddressSpace in the
memory API, implement it with a lookup of the dispatch tree.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 688d3f0..81e0e41 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -866,6 +866,21 @@
hwaddr *xlat, hwaddr *len,
bool is_write);
+/* address_space_access_valid: check for validity of accessing an address
+ * space range
+ *
+ * Check whether memory is assigned to the given address space range.
+ *
+ * For now, addr and len should be aligned to a page size. This limitation
+ * will be lifted in the future.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @len: length of the area to be checked
+ * @is_write: indicates the transfer direction
+ */
+bool address_space_access_valid(AddressSpace *as, hwaddr addr, int len, bool is_write);
+
/* address_space_map: map a physical memory region into a host virtual address
*
* May map a subset of the requested range, given by and returned in @plen.
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index a52c93a..02e0dcd 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -113,7 +113,8 @@
DMADirection dir)
{
if (!dma_has_iommu(dma)) {
- return true;
+ return address_space_access_valid(dma->as, addr, len,
+ dir == DMA_DIRECTION_FROM_DEVICE);
} else {
return iommu_dma_memory_valid(dma, addr, len, dir);
}
