[Qemu-devel] [PATCH] spapr-pci: remove io ports workaround

[Greg Kurz]

In the past, IO space could not be mapped into the memory address space
so we introduced a workaround for that. Nowadays it does not look
necessary so we can remove the workaround and make sPAPR PCI
configuration simplier.

Signed-off-by: Greg Kurz <address@hidden>
---

There has been a previous post for this patch:

        http://patchwork.ozlabs.org/patch/299123/

Since then, things have evolved:
- the kvm_mem_ioeventfd_add failure was fixed by the "KVM: fix addr type 
  for KVM_IOEVENTFD" commit (584f2be).
- Alexey's NACK got addressed in SLOF:

        https://github.com/aik/SLOF/commit/020220e

Cheers.

--
Greg

 hw/ppc/spapr_pci.c |   13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 66ddf10..3b7d978 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -564,23 +564,14 @@ static int spapr_phb_init(SysBusDevice *s)
     memory_region_add_subregion(get_system_memory(), sphb->mem_win_addr,
                                 &sphb->memwindow);
 
-    /* On ppc, we only have MMIO no specific IO space from the CPU
-     * perspective.  In theory we ought to be able to embed the PCI IO
-     * memory region direction in the system memory space.  However,
-     * if any of the IO BAR subregions use the old_portio mechanism,
-     * that won't be processed properly unless accessed from the
-     * system io address space.  This hack to bounce things via
-     * system_io works around the problem until all the users of
-     * old_portion are updated */
+    /* Initialize IO regions */
     sprintf(namebuf, "%s.io", sphb->dtbusname);
     memory_region_init(&sphb->iospace, OBJECT(sphb),
                        namebuf, SPAPR_PCI_IO_WIN_SIZE);
-    /* FIXME: fix to support multiple PHBs */
-    memory_region_add_subregion(get_system_io(), 0, &sphb->iospace);
 
     sprintf(namebuf, "%s.io-alias", sphb->dtbusname);
     memory_region_init_alias(&sphb->iowindow, OBJECT(sphb), namebuf,
-                             get_system_io(), 0, SPAPR_PCI_IO_WIN_SIZE);
+                             &sphb->iospace, 0, SPAPR_PCI_IO_WIN_SIZE);
     memory_region_add_subregion(get_system_memory(), sphb->io_win_addr,
                                 &sphb->iowindow);
     /*