Commit 4f917406 authored by Peter Maydell's avatar Peter Maydell Committed by Aleksandar Markovic
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hw/pci-host/xilinx-pcie: don't make "io" region be RAM 



Currently we use memory_region_init_rom_nomigrate() to create
the "io" memory region to pass to pci_register_root_bus().
This is a dummy region, because this PCI controller doesn't
support accesses to PCI IO space.

There is no reason for the dummy region to be a RAM region;
it is only used as a place where PCI BARs can be mapped,
and if you could get a PCI card to do a bus master access
to the IO space it should not get acts-like-RAM behaviour.
Use a simple container memory region instead. (We do have
one PCI card model which can do bus master accesses to IO
space -- the LSI53C895A SCSI adaptor.)

This avoids the oddity of having a memory region which is
RAM but where the RAM is not migrated.

Note that the size of the region we use here has no
effect on behaviour.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarAlistair Francis <alistair.francis@wdc.com>
Signed-off-by: default avatarAleksandar Markovic <aleksandar.markovic@mips.com>
parent 917b77f5

hw/pci-host/xilinx-pcie.c

+2 −3
Original line number Diff line number Diff line
@@ -120,9 +120,8 @@ static void xilinx_pcie_host_realize(DeviceState *dev, Error **errp) 
    memory_region_init(&s->mmio, OBJECT(s), "mmio", UINT64_MAX);

    memory_region_set_enabled(&s->mmio, false);



    /* dummy I/O region */

    memory_region_init_ram_nomigrate(&s->io, OBJECT(s), "io", 16, NULL);

    memory_region_set_enabled(&s->io, false);

    /* dummy PCI I/O region (not visible to the CPU) */

    memory_region_init(&s->io, OBJECT(s), "io", 16);



    /* interrupt out */

    qdev_init_gpio_out_named(dev, &s->irq, "interrupt_out", 1);