On Mon, Sep 16, 2013 at 12:11:32PM +0300, Marcel Apfelbaum wrote:
> On Mon, 2013-09-16 at 12:04 +0300, Michael S. Tsirkin wrote:
> > On Mon, Sep 16, 2013 at 11:21:16AM +0300, Marcel Apfelbaum wrote:
> > > 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 <marce...@redhat.com>
So let's hold on to this patch and see how the full
implementation interacts with it.
Let's apply 1-2 - I'll put it on my tree unless someone objects.
> > > ---
> > > Changes from v4:
> > > - Addressed Michael S. Tsirkin comments
> > > - Changed PCI master_abort_mem ops endian-nes to DEVICE_LITTLE_ENDIAN
> > > - Fixed: overlap master_abort_mem at offset 0, not at
> > > bus->address_space_mem.addr
> > >
> > > hw/pci/pci.c | 26 ++++++++++++++++++++++++++
> > > include/hw/pci/pci_bus.h | 1 +
> > > 2 files changed, 27 insertions(+)
> > >
> > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> > > index ad1c1ca..d8a1b11 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);
> > >
> >
> > Does this handle devices behind bridges?
> Yes, tested also for devices behind bridge.
BTW why does this only handle memory?
IO should be exactly identical, shouldn't it?
> >
> >
> > > diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
> > > index 9df1788..2ad5edb 100644
> > > --- a/include/hw/pci/pci_bus.h
> > > +++ b/include/hw/pci/pci_bus.h
> > > @@ -23,6 +23,7 @@ struct PCIBus {
> > > PCIDevice *parent_dev;
> > > MemoryRegion *address_space_mem;
> > > MemoryRegion *address_space_io;
> > > + MemoryRegion master_abort_mem;
> > >
> >
> > Looks like this field is left uninitialized for bridge
> > devices (they don't seem to call pci_bus_init)?
> The bridges have no influence with respect to master_abort_mem
> as it handles *all* unassigned addresses for PCI address space.
> As stated above, it was tested.
>
> Thanks,
> Marcel
>
>
> >
> > > QLIST_HEAD(, PCIBus) child; /* this will be replaced by qdev later */
> > > QLIST_ENTRY(PCIBus) sibling;/* this will be replaced by qdev later */
> > > --
> > > 1.8.3.1
>
>
