diff --git a/exec.c b/exec.c
index e97071a..81f536a 100644
--- a/exec.c
+++ b/exec.c
@@ -373,9 +373,9 @@ static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
     return false;
 }
 
-MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
-                                      hwaddr *xlat, hwaddr *plen,
-                                      bool is_write)
+static MemoryRegion *_address_space_translate(AddressSpace *as, DeviceState *dev,
+					hwaddr addr, hwaddr *xlat,
+					hwaddr *plen, bool is_write)
 {
     IOMMUTLBEntry iotlb;
     MemoryRegionSection *section;
@@ -392,7 +392,11 @@ MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
             break;
         }
 
-        iotlb = mr->iommu_ops->translate(mr, addr, is_write);
+        if (mr->iommu_ops->translate_dev && dev)
+            iotlb = mr->iommu_ops->translate_dev(mr, dev, addr, is_write);
+        else
+            iotlb = mr->iommu_ops->translate(mr, addr, is_write);
+
         addr = ((iotlb.translated_addr & ~iotlb.addr_mask)
                 | (addr & iotlb.addr_mask));
         len = MIN(len, (addr | iotlb.addr_mask) - addr + 1);
@@ -415,6 +419,20 @@ MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
     return mr;
 }
 
+MemoryRegion *address_space_translate_dev(AddressSpace *as, DeviceState *dev,
+					 hwaddr addr, hwaddr *xlat,
+					 hwaddr *plen, bool is_write)
+{
+    return _address_space_translate(as, dev, addr, xlat, plen, is_write);
+}
+
+MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
+                                      hwaddr *xlat, hwaddr *plen,
+                                      bool is_write)
+{
+    return _address_space_translate(as, NULL, addr, xlat, plen, is_write);
+}
+
 /* Called from RCU critical section */
 MemoryRegionSection *
 address_space_translate_for_iotlb(CPUState *cpu, hwaddr addr,
@@ -2305,8 +2323,9 @@ static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr)
     return l;
 }
 
-bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
-                      int len, bool is_write)
+
+static bool _address_space_rw(AddressSpace *as, DeviceState *dev, hwaddr addr, uint8_t *buf,
+                        int len, bool is_write)
 {
     hwaddr l;
     uint8_t *ptr;
@@ -2317,7 +2336,10 @@ bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
 
     while (len > 0) {
         l = len;
-        mr = address_space_translate(as, addr, &addr1, &l, is_write);
+	if (dev)
+            mr = address_space_translate_dev(as, dev, addr, &addr1, &l, is_write);
+	else
+            mr = address_space_translate(as, addr, &addr1, &l, is_write);
 
         if (is_write) {
             if (!memory_access_is_direct(mr, is_write)) {
@@ -2397,6 +2419,18 @@ bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
     return error;
 }
 
+bool address_space_rw_dev(AddressSpace *as, DeviceState *dev, hwaddr addr,
+			 uint8_t *buf, int len, bool is_write)
+{
+    return _address_space_rw(as, dev, addr, buf, len, is_write);
+}
+
+bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
+                       int len, bool is_write)
+{
+    return _address_space_rw(as, NULL, addr, buf, len, is_write);
+}
+
 bool address_space_write(AddressSpace *as, hwaddr addr,
                          const uint8_t *buf, int len)
 {
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 06ffa1d..8d6b7a9 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -131,6 +131,8 @@ typedef struct MemoryRegionIOMMUOps MemoryRegionIOMMUOps;
 struct MemoryRegionIOMMUOps {
     /* Return a TLB entry that contains a given address. */
     IOMMUTLBEntry (*translate)(MemoryRegion *iommu, hwaddr addr, bool is_write);
+    IOMMUTLBEntry (*translate_dev)(MemoryRegion *iommu, DeviceState *dev, 
+					hwaddr addr, bool is_write);
 };
 
 typedef struct CoalescedMemoryRange CoalescedMemoryRange;
@@ -1054,6 +1056,7 @@ void address_space_destroy(AddressSpace *as);
 
 /**
  * address_space_rw: read from or write to an address space.
+ * address_space_rw_dev: A variant of address_space_rw, to pass on requesting device id.
  *
  * Return true if the operation hit any unassigned memory or encountered an
  * IOMMU fault.
@@ -1066,6 +1069,8 @@ void address_space_destroy(AddressSpace *as);
 bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
                       int len, bool is_write);
 
+bool address_space_rw_dev(AddressSpace *as, DeviceState *dev, hwaddr addr,
+			 uint8_t *buf, int len, bool is_write);
 /**
  * address_space_write: write to address space.
  *
@@ -1105,6 +1110,10 @@ MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
                                       hwaddr *xlat, hwaddr *len,
                                       bool is_write);
 
+MemoryRegion *address_space_translate_dev(AddressSpace *as, DeviceState *dev, hwaddr addr,
+                                      hwaddr *xlat, hwaddr *len,
+                                      bool is_write);
+
 /* address_space_access_valid: check for validity of accessing an address
  * space range
  *
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index be2d9b8..faa1df3 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -493,6 +493,12 @@ pci_config_set_interrupt_pin(uint8_t *pci_config, uint8_t val)
     pci_set_byte(&pci_config[PCI_INTERRUPT_PIN], val);
 }
 
+static inline uint16_t
+pci_get_arid(PCIDevice *pcidev)
+{
+	uint16_t busnum = (pci_bus_num(pcidev->bus)) & 0xff << 8;
+	return busnum | (pcidev->devfn & 0x7); 
+}
 /*
  * helper functions to do bit mask operation on configuration space.
  * Just to set bit, use test-and-set and discard returned value.
@@ -674,7 +680,7 @@ static inline AddressSpace *pci_get_address_space(PCIDevice *dev)
 static inline int pci_dma_rw(PCIDevice *dev, dma_addr_t addr,
                              void *buf, dma_addr_t len, DMADirection dir)
 {
-    dma_memory_rw(pci_get_address_space(dev), addr, buf, len, dir);
+    dma_memory_rw_dev(pci_get_address_space(dev), DEVICE(dev), addr, buf, len, dir);
     return 0;
 }
 
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index 3f2f4c8..ae84080 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -84,6 +84,14 @@ static inline bool dma_memory_valid(AddressSpace *as,
                                       dir == DMA_DIRECTION_FROM_DEVICE);
 }
 
+/* @dev: Requesting Device */
+static inline int dma_memory_rw_relaxed_dev(AddressSpace *as, DeviceState *dev,
+					 dma_addr_t addr, void *buf, dma_addr_t len,
+                                        DMADirection dir)
+{
+    return address_space_rw_dev(as, dev, addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
+}
+
 static inline int dma_memory_rw_relaxed(AddressSpace *as, dma_addr_t addr,
                                         void *buf, dma_addr_t len,
                                         DMADirection dir)
@@ -104,6 +112,15 @@ static inline int dma_memory_write_relaxed(AddressSpace *as, dma_addr_t addr,
                                  DMA_DIRECTION_FROM_DEVICE);
 }
 
+/* @dev: Requesting Device */
+static inline int dma_memory_rw_dev(AddressSpace *as, DeviceState *dev,
+				dma_addr_t addr, void *buf, dma_addr_t len,
+				DMADirection dir)
+{
+	dma_barrier(as, dir);
+	return dma_memory_rw_relaxed_dev(as, dev, addr, buf, len, dir);
+}
+
 static inline int dma_memory_rw(AddressSpace *as, dma_addr_t addr,
                                 void *buf, dma_addr_t len,
                                 DMADirection dir)
