Re: [Qemu-devel] [PATCH RFC 2/3] hw/pci: add MemoryRegion ops for unassigned pci addresses

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Sep 02, 2013 at 05:13:08PM +0300, Marcel Apfelbaum wrote:
> The MemoryRegions assigned with this ops shall "intercept"
> the accesses to unassigned pci address space and the
> associated callback will set MASTER ABORT bit in the
> STATUS register of the device that initiated the
> transaction as defined in PCI spec.
> 
> Note: This implementation assumes that all the reads/writes to
> the pci address space are done by the cpu.
> 
> Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
> ---
>  hw/pci/pci.c         | 18 ++++++++++++++++++
>  include/hw/pci/pci.h |  3 +++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index 4c004f5..f0289fc 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -2229,6 +2229,24 @@ MemoryRegion *pci_address_space_io(PCIDevice *dev)
>      return dev->bus->address_space_io;
>  }
>  
> +static bool pci_unassigned_mem_accepts(void *opaque, hwaddr addr,
> +                                       unsigned size, bool is_write)
> +{
> +    PCIDevice *d = opaque;
> +
> +    /* FIXME assumption: the cpu initiated the pci transaction
> +     * and not another pci device */

/*
 * Multiline
 * comments
 */


> +    pci_word_test_and_set_mask(d->config + PCI_STATUS,
> +                               PCI_STATUS_REC_MASTER_ABORT);
> +
> +    return false;
> +}
> +
> +const MemoryRegionOps pci_unassigned_mem_ops = {
> +    .valid.accepts = pci_unassigned_mem_accepts,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
>  static void pci_device_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *k = DEVICE_CLASS(klass);
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index ccec2ba..854681c 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -329,6 +329,9 @@ int pci_device_load(PCIDevice *s, QEMUFile *f);
>  MemoryRegion *pci_address_space(PCIDevice *dev);
>  MemoryRegion *pci_address_space_io(PCIDevice *dev);
>  
> +#define PCI_UNASSIGNED_MEM_PRIORITY -1
> +extern const MemoryRegionOps pci_unassigned_mem_ops;
> +
>  typedef void (*pci_set_irq_fn)(void *opaque, int irq_num, int level);
>  typedef int (*pci_map_irq_fn)(PCIDevice *pci_dev, int irq_num);
>  typedef PCIINTxRoute (*pci_route_irq_fn)(void *opaque, int pin);
> -- 
> 1.8.3.1