From a53ae8e934cd54686875b5bcfc2f434244ee55d6 Mon Sep 17 00:00:00 2001 From: Marcel Apfelbaum Date: Mon, 16 Sep 2013 11:21:16 +0300 Subject: hw/pci: partially handle pci master abort A MemoryRegion with negative priority was created and it spans over all the pci address space. It "intercepts" the accesses to unassigned pci address space and will follow the pci spec: 1. returns -1 on read 2. does nothing on write Note: setting the RECEIVED MASTER ABORT bit in the STATUS register of the device that initiated the transaction will be implemented in another series Signed-off-by: Marcel Apfelbaum Acked-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/pci/pci.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'hw') diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 00554a05ac..25626b8e19 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -283,6 +283,24 @@ const char *pci_root_bus_path(PCIDevice *dev) return rootbus->qbus.name; } +static uint64_t master_abort_mem_read(void *opaque, hwaddr addr, unsigned size) +{ + return -1ULL; +} + +static void master_abort_mem_write(void *opaque, hwaddr addr, uint64_t val, + unsigned size) +{ +} + +static const MemoryRegionOps master_abort_mem_ops = { + .read = master_abort_mem_read, + .write = master_abort_mem_write, + .endianness = DEVICE_LITTLE_ENDIAN, +}; + +#define MASTER_ABORT_MEM_PRIORITY INT_MIN + static void pci_bus_init(PCIBus *bus, DeviceState *parent, const char *name, MemoryRegion *address_space_mem, @@ -294,6 +312,14 @@ static void pci_bus_init(PCIBus *bus, DeviceState *parent, bus->address_space_mem = address_space_mem; bus->address_space_io = address_space_io; + + memory_region_init_io(&bus->master_abort_mem, OBJECT(bus), + &master_abort_mem_ops, bus, "pci-master-abort", + memory_region_size(bus->address_space_mem)); + memory_region_add_subregion_overlap(bus->address_space_mem, + 0, &bus->master_abort_mem, + MASTER_ABORT_MEM_PRIORITY); + /* host bridge */ QLIST_INIT(&bus->child); -- cgit v1.2.1