When updating memory mappings, pci_bridge_update_mappings() performed
the following operations:
1. Start a transaction
2. Delete the subregions from the container
3. Unparent the subregions
4. Initialize the subregions
5. End the transaction
This assumes the old subregion instances are finalized immediately after
3, but it is not true; the finalization is delayed until 5. Remove the
assumption by using functions to dynamically update MemoryRegions.
Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
---
include/hw/pci/pci.h | 1 +
hw/pci/pci.c | 2 +-
hw/pci/pci_bridge.c | 96 ++++++++++++++++++++++++++++------------------------
3 files changed, 54 insertions(+), 45 deletions(-)
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 6b7d3ac8a3611d00d1c1c949c260f3dd44d36cc4..d0bd214b4e11eccc085f7ebe421d170f37552ac3 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -256,6 +256,7 @@ void pci_register_bar(PCIDevice *pci_dev, int region_num,
uint8_t attr, MemoryRegion *memory);
void pci_register_vga(PCIDevice *pci_dev, MemoryRegion *mem,
MemoryRegion *io_lo, MemoryRegion *io_hi);
+void pci_update_vga(PCIDevice *pci_dev);
void pci_unregister_vga(PCIDevice *pci_dev);
pcibus_t pci_get_bar_addr(PCIDevice *pci_dev, int region_num);
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index c70b5ceebaf1f2b10768bd030526cbb518da2b8d..516029f66cda6705bded15322cb6f7eb3d42f82c 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1521,7 +1521,7 @@ void pci_register_bar(PCIDevice *pci_dev, int region_num,
}
}
-static void pci_update_vga(PCIDevice *pci_dev)
+void pci_update_vga(PCIDevice *pci_dev)
{
uint16_t cmd;
diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c
index 76255c4cd8929cf9f350af4be1a8448791d52afa..240d0f904de9771f81a392ad26be6ba38a41e4f6 100644
--- a/hw/pci/pci_bridge.c
+++ b/hw/pci/pci_bridge.c
@@ -145,11 +145,10 @@ pcibus_t pci_bridge_get_limit(const PCIDevice *bridge, uint8_t type)
return limit;
}
-static void pci_bridge_init_alias(PCIBridge *bridge, MemoryRegion *alias,
- uint8_t type, const char *name,
- MemoryRegion *space,
- MemoryRegion *parent_space,
- bool enabled)
+static void pci_bridge_update_alias(PCIBridge *bridge, bool init,
+ MemoryRegion *alias, uint8_t type,
+ const char *name, MemoryRegion *space,
+ MemoryRegion *parent_space, bool enabled)
{
PCIDevice *bridge_dev = PCI_DEVICE(bridge);
pcibus_t base = pci_bridge_get_base(bridge_dev, type);
@@ -158,25 +157,37 @@ static void pci_bridge_init_alias(PCIBridge *bridge, MemoryRegion *alias,
* Apparently no way to do this with existing memory APIs. */
pcibus_t size = enabled && limit >= base ? limit + 1 - base : 0;
- memory_region_init_alias(alias, OBJECT(bridge), name, space, base, size);
+ if (init) {
+ memory_region_init_alias(alias, OBJECT(bridge), name, space, base, size);
+ } else {
+ memory_region_set_size(alias, size);
+ memory_region_set_alias_offset(alias, base);
+ }
+
memory_region_add_subregion_overlap(parent_space, base, alias, 1);
}
-static void pci_bridge_init_vga_aliases(PCIBridge *br, PCIBus *parent,
- MemoryRegion *alias_vga)
+static void pci_bridge_update_vga_aliases(PCIBridge *br, bool init,
+ PCIBus *parent,
+ MemoryRegion *alias_vga)
{
PCIDevice *pd = PCI_DEVICE(br);
uint16_t brctl = pci_get_word(pd->config + PCI_BRIDGE_CONTROL);
- memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_LO], OBJECT(br),
- "pci_bridge_vga_io_lo", &br->address_space_io,
- QEMU_PCI_VGA_IO_LO_BASE, QEMU_PCI_VGA_IO_LO_SIZE);
- memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_HI], OBJECT(br),
- "pci_bridge_vga_io_hi", &br->address_space_io,
- QEMU_PCI_VGA_IO_HI_BASE, QEMU_PCI_VGA_IO_HI_SIZE);
- memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_MEM], OBJECT(br),
- "pci_bridge_vga_mem", &br->address_space_mem,
- QEMU_PCI_VGA_MEM_BASE, QEMU_PCI_VGA_MEM_SIZE);
+ if (init) {
+ memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_LO], OBJECT(br),
+ "pci_bridge_vga_io_lo", &br->address_space_io,
+ QEMU_PCI_VGA_IO_LO_BASE,
+ QEMU_PCI_VGA_IO_LO_SIZE);
+ memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_HI], OBJECT(br),
+ "pci_bridge_vga_io_hi", &br->address_space_io,
+ QEMU_PCI_VGA_IO_HI_BASE,
+ QEMU_PCI_VGA_IO_HI_SIZE);
+ memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_MEM], OBJECT(br),
+ "pci_bridge_vga_mem", &br->address_space_mem,
+ QEMU_PCI_VGA_MEM_BASE,
+ QEMU_PCI_VGA_MEM_SIZE);
+ }
if (brctl & PCI_BRIDGE_CTL_VGA) {
pci_register_vga(pd, &alias_vga[QEMU_PCI_VGA_MEM],
@@ -185,33 +196,33 @@ static void pci_bridge_init_vga_aliases(PCIBridge *br, PCIBus *parent,
}
}
-static void pci_bridge_region_init(PCIBridge *br)
+static void pci_bridge_region_update(PCIBridge *br, bool init)
{
PCIDevice *pd = PCI_DEVICE(br);
PCIBus *parent = pci_get_bus(pd);
PCIBridgeWindows *w = &br->windows;
uint16_t cmd = pci_get_word(pd->config + PCI_COMMAND);
- pci_bridge_init_alias(br, &w->alias_pref_mem,
- PCI_BASE_ADDRESS_MEM_PREFETCH,
- "pci_bridge_pref_mem",
- &br->address_space_mem,
- parent->address_space_mem,
- cmd & PCI_COMMAND_MEMORY);
- pci_bridge_init_alias(br, &w->alias_mem,
- PCI_BASE_ADDRESS_SPACE_MEMORY,
- "pci_bridge_mem",
- &br->address_space_mem,
- parent->address_space_mem,
- cmd & PCI_COMMAND_MEMORY);
- pci_bridge_init_alias(br, &w->alias_io,
- PCI_BASE_ADDRESS_SPACE_IO,
- "pci_bridge_io",
- &br->address_space_io,
- parent->address_space_io,
- cmd & PCI_COMMAND_IO);
-
- pci_bridge_init_vga_aliases(br, parent, w->alias_vga);
+ pci_bridge_update_alias(br, init, &w->alias_pref_mem,
+ PCI_BASE_ADDRESS_MEM_PREFETCH,
+ "pci_bridge_pref_mem",
+ &br->address_space_mem,
+ parent->address_space_mem,
+ cmd & PCI_COMMAND_MEMORY);
+ pci_bridge_update_alias(br, init, &w->alias_mem,
+ PCI_BASE_ADDRESS_SPACE_MEMORY,
+ "pci_bridge_mem",
+ &br->address_space_mem,
+ parent->address_space_mem,
+ cmd & PCI_COMMAND_MEMORY);
+ pci_bridge_update_alias(br, init, &w->alias_io,
+ PCI_BASE_ADDRESS_SPACE_IO,
+ "pci_bridge_io",
+ &br->address_space_io,
+ parent->address_space_io,
+ cmd & PCI_COMMAND_IO);
+
+ pci_bridge_update_vga_aliases(br, init, parent, w->alias_vga);
}
static void pci_bridge_region_del(PCIBridge *br, PCIBridgeWindows *w)
@@ -237,14 +248,11 @@ static void pci_bridge_region_cleanup(PCIBridge *br, PCIBridgeWindows *w)
void pci_bridge_update_mappings(PCIBridge *br)
{
- PCIBridgeWindows *w = &br->windows;
-
/* Make updates atomic to: handle the case of one VCPU updating the bridge
* while another accesses an unaffected region. */
memory_region_transaction_begin();
- pci_bridge_region_del(br, w);
- pci_bridge_region_cleanup(br, w);
- pci_bridge_region_init(br);
+ pci_bridge_region_del(br, &br->windows);
+ pci_bridge_region_update(br, false);
memory_region_transaction_commit();
}
@@ -386,7 +394,7 @@ void pci_bridge_initfn(PCIDevice *dev, const char *typename)
memory_region_init(&br->address_space_io, OBJECT(br), "pci_bridge_io",
4 * GiB);
address_space_init(&br->as_io, &br->address_space_io, "pci_bridge_pci_io");
- pci_bridge_region_init(br);
+ pci_bridge_region_update(br, true);
QLIST_INIT(&sec_bus->child);
QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);
--
2.51.0