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.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
dma-helpers.c | 5 +++++
exec.c | 25 +++++++++++++++++++++++++
include/exec/memory.h | 14 ++++++++++++++
include/sysemu/dma.h | 3 ++-
4 files changed, 46 insertions(+), 1 deletion(-)
diff --git a/dma-helpers.c b/dma-helpers.c
index 272632f..2962b69 100644
--- a/dma-helpers.c
+++ b/dma-helpers.c
@@ -298,6 +298,11 @@ bool iommu_dma_memory_valid(DMAContext *dma, dma_addr_t
addr, dma_addr_t len,
plen = len;
}
+ if (!address_space_valid(dma->as, paddr, len,
+ dir == DMA_DIRECTION_FROM_DEVICE)) {
+ return false;
+ }
+
len -= plen;
addr += plen;
}
diff --git a/exec.c b/exec.c
index 8d91221..8f1b507 100644
--- a/exec.c
+++ b/exec.c
@@ -2079,6 +2079,31 @@ static void cpu_notify_map_clients(void)
}
}
+bool address_space_valid(AddressSpace *as, hwaddr addr, int len, bool is_write)
+{
+ AddressSpaceDispatch *d = as->dispatch;
+ MemoryRegionSection *section;
+ int l;
+ hwaddr page;
+
+ while (len > 0) {
+ page = addr & TARGET_PAGE_MASK;
+ l = (page + TARGET_PAGE_SIZE) - addr;
+ if (l > len) {
+ l = len;
+ }
+ section = phys_page_find(d, addr >> TARGET_PAGE_BITS);
+ if (section->mr == &io_mem_unassigned ||
+ (is_write && section->mr->readonly)) {
+ return false;
+ }
+
+ len -= l;
+ addr += l;
+ }
+ return true;
+}
+
/* Map a physical memory region into a host virtual address.
* May map a subset of the requested range, given by and returned in *plen.
* May return NULL if resources needed to perform the mapping are exhausted.
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 6ed593c..2e5fd11 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -860,6 +860,20 @@ void address_space_write(AddressSpace *as, hwaddr addr,
*/
void address_space_read(AddressSpace *as, hwaddr addr, uint8_t *buf, int len);
+/* address_space_valid: check for validity of 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_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..2e239dc 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -113,7 +113,8 @@ static inline bool dma_memory_valid(DMAContext *dma,
DMADirection dir)
{
if (!dma_has_iommu(dma)) {
- return true;
+ return address_space_valid(dma->as, addr, len,
+ dir == DMA_DIRECTION_FROM_DEVICE);
} else {
return iommu_dma_memory_valid(dma, addr, len, dir);
}
--
1.8.1.4
