1 files changed, 24 insertions, 1 deletions

diff --git a/hw/pci.c b/hw/pci.c
index 2ca6ff6..7eeaac0 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -33,6 +33,7 @@
 #include "qmp-commands.h"
 #include "msi.h"
 #include "msix.h"
+#include "exec-memory.h"
 
 //#define DEBUG_PCI
 #ifdef DEBUG_PCI
@@ -777,6 +778,17 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
     pci_dev->bus = bus;
     if (bus->dma_context_fn) {
         pci_dev->dma = bus->dma_context_fn(bus, bus->dma_context_opaque, devfn);
+    } else {
+        /* FIXME: Make dma_context_fn use MemoryRegions instead, so this path is
+         * taken unconditionally */
+        /* FIXME: inherit memory region from bus creator */
+        memory_region_init_alias(&pci_dev->bus_master_enable_region, "bus master",
+                                 get_system_memory(), 0,
+                                 memory_region_size(get_system_memory()));
+        memory_region_set_enabled(&pci_dev->bus_master_enable_region, false);
+        address_space_init(&pci_dev->bus_master_as, &pci_dev->bus_master_enable_region);
+        pci_dev->dma = g_new(DMAContext, 1);
+        dma_context_init(pci_dev->dma, &pci_dev->bus_master_as, NULL, NULL, NULL);
     }
     pci_dev->devfn = devfn;
     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
@@ -830,6 +842,13 @@ static void do_pci_unregister_device(PCIDevice *pci_dev)
     qemu_free_irqs(pci_dev->irq);
     pci_dev->bus->devices[pci_dev->devfn] = NULL;
     pci_config_free(pci_dev);
+
+    if (!pci_dev->bus->dma_context_fn) {
+        address_space_destroy(&pci_dev->bus_master_as);
+        memory_region_destroy(&pci_dev->bus_master_enable_region);
+        g_free(pci_dev->dma);
+        pci_dev->dma = NULL;
+    }
 }
 
 static void pci_unregister_io_regions(PCIDevice *pci_dev)
@@ -1051,8 +1070,12 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l)
         range_covers_byte(addr, l, PCI_COMMAND))
         pci_update_mappings(d);
 
-    if (range_covers_byte(addr, l, PCI_COMMAND))
+    if (range_covers_byte(addr, l, PCI_COMMAND)) {
         pci_update_irq_disabled(d, was_irq_disabled);
+        memory_region_set_enabled(&d->bus_master_enable_region,
+                                  pci_get_word(d->config + PCI_COMMAND)
+                                    & PCI_COMMAND_MASTER);
+    }
 
     msi_write_config(d, addr, val, l);
     msix_write_config(d, addr, val, l);