pci: Let pci_dma_rw() propagate MemTxResult

dma_memory_rw() returns a MemTxResult type.
Do not discard it, return it to the caller.

Reviewed-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201023151923.3243652-9-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/hw/pci/pci.h

@@ -781,8 +781,22 @@ static inline AddressSpace *pci_get_address_space(PCIDevice *dev)
     return &dev->bus_master_as;
 }
 
-static inline int pci_dma_rw(PCIDevice *dev, dma_addr_t addr,
-                             void *buf, dma_addr_t len, DMADirection dir)
+/**
+ * pci_dma_rw: Read from or write to an address space from PCI device.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).
+ *
+ * @dev: #PCIDevice doing the memory access
+ * @addr: address within the #PCIDevice address space
+ * @buf: buffer with the data transferred
+ * @len: the number of bytes to read or write
+ * @dir: indicates the transfer direction
+ */
+static inline MemTxResult pci_dma_rw(PCIDevice *dev, dma_addr_t addr,
+                                     void *buf, dma_addr_t len,
+                                     DMADirection dir)
 {
     return dma_memory_rw(pci_get_address_space(dev), addr, buf, len, dir);
 }