diff options
| -rw-r--r-- | hw/core/machine.c | 4 | ||||
| -rw-r--r-- | hw/pci-host/gpex.c | 56 | ||||
| -rw-r--r-- | include/hw/pci-host/gpex.h | 4 |
3 files changed, 60 insertions, 4 deletions
diff --git a/hw/core/machine.c b/hw/core/machine.c index cebcdcc351..0f5ce43d0c 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -36,7 +36,9 @@ #include "hw/virtio/virtio.h" #include "hw/virtio/virtio-pci.h" -GlobalProperty hw_compat_6_0[] = {}; +GlobalProperty hw_compat_6_0[] = { + { "gpex-pcihost", "allow-unmapped-accesses", "false" }, +}; const size_t hw_compat_6_0_len = G_N_ELEMENTS(hw_compat_6_0); GlobalProperty hw_compat_5_2[] = { diff --git a/hw/pci-host/gpex.c b/hw/pci-host/gpex.c index 2bdbe7b456..a6752fac5e 100644 --- a/hw/pci-host/gpex.c +++ b/hw/pci-host/gpex.c @@ -83,12 +83,51 @@ static void gpex_host_realize(DeviceState *dev, Error **errp) int i; pcie_host_mmcfg_init(pex, PCIE_MMCFG_SIZE_MAX); + sysbus_init_mmio(sbd, &pex->mmio); + + /* + * Note that the MemoryRegions io_mmio and io_ioport that we pass + * to pci_register_root_bus() are not the same as the + * MemoryRegions io_mmio_window and io_ioport_window that we + * expose as SysBus MRs. The difference is in the behaviour of + * accesses to addresses where no PCI device has been mapped. + * + * io_mmio and io_ioport are the underlying PCI view of the PCI + * address space, and when a PCI device does a bus master access + * to a bad address this is reported back to it as a transaction + * failure. + * + * io_mmio_window and io_ioport_window implement "unmapped + * addresses read as -1 and ignore writes"; this is traditional + * x86 PC behaviour, which is not mandated by the PCI spec proper + * but expected by much PCI-using guest software, including Linux. + * + * In the interests of not being unnecessarily surprising, we + * implement it in the gpex PCI host controller, by providing the + * _window MRs, which are containers with io ops that implement + * the 'background' behaviour and which hold the real PCI MRs as + * subregions. + */ memory_region_init(&s->io_mmio, OBJECT(s), "gpex_mmio", UINT64_MAX); memory_region_init(&s->io_ioport, OBJECT(s), "gpex_ioport", 64 * 1024); - sysbus_init_mmio(sbd, &pex->mmio); - sysbus_init_mmio(sbd, &s->io_mmio); - sysbus_init_mmio(sbd, &s->io_ioport); + if (s->allow_unmapped_accesses) { + memory_region_init_io(&s->io_mmio_window, OBJECT(s), + &unassigned_io_ops, OBJECT(s), + "gpex_mmio_window", UINT64_MAX); + memory_region_init_io(&s->io_ioport_window, OBJECT(s), + &unassigned_io_ops, OBJECT(s), + "gpex_ioport_window", 64 * 1024); + + memory_region_add_subregion(&s->io_mmio_window, 0, &s->io_mmio); + memory_region_add_subregion(&s->io_ioport_window, 0, &s->io_ioport); + sysbus_init_mmio(sbd, &s->io_mmio_window); + sysbus_init_mmio(sbd, &s->io_ioport_window); + } else { + sysbus_init_mmio(sbd, &s->io_mmio); + sysbus_init_mmio(sbd, &s->io_ioport); + } + for (i = 0; i < GPEX_NUM_IRQS; i++) { sysbus_init_irq(sbd, &s->irq[i]); s->irq_num[i] = -1; @@ -108,6 +147,16 @@ static const char *gpex_host_root_bus_path(PCIHostState *host_bridge, return "0000:00"; } +static Property gpex_host_properties[] = { + /* + * Permit CPU accesses to unmapped areas of the PIO and MMIO windows + * (discarding writes and returning -1 for reads) rather than aborting. + */ + DEFINE_PROP_BOOL("allow-unmapped-accesses", GPEXHost, + allow_unmapped_accesses, true), + DEFINE_PROP_END_OF_LIST(), +}; + static void gpex_host_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); @@ -117,6 +166,7 @@ static void gpex_host_class_init(ObjectClass *klass, void *data) dc->realize = gpex_host_realize; set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories); dc->fw_name = "pci"; + device_class_set_props(dc, gpex_host_properties); } static void gpex_host_initfn(Object *obj) diff --git a/include/hw/pci-host/gpex.h b/include/hw/pci-host/gpex.h index d48a020a95..fcf8b63820 100644 --- a/include/hw/pci-host/gpex.h +++ b/include/hw/pci-host/gpex.h @@ -49,8 +49,12 @@ struct GPEXHost { MemoryRegion io_ioport; MemoryRegion io_mmio; + MemoryRegion io_ioport_window; + MemoryRegion io_mmio_window; qemu_irq irq[GPEX_NUM_IRQS]; int irq_num[GPEX_NUM_IRQS]; + + bool allow_unmapped_accesses; }; struct GPEXConfig { |