pseries: Implement IOMMU and DMA for PAPR PCI devices

Currently the pseries machine emulation does not support DMA for emulated
PCI devices, because the PAPR spec always requires a (guest visible,
paravirtualized) IOMMU which was not implemented.  Now that we have
infrastructure for IOMMU emulation, we can correct this and allow PCI DMA
for pseries.

With the existing PAPR IOMMU code used for VIO devices, this is almost
trivial. We use a single DMAContext for each (virtual) PCI host bridge,
which is the usual configuration on real PAPR machines (which often have
_many_ PCI host bridges).

Cc: Alex Graf <agraf@suse.de>

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/hw/spapr_pci.c b/hw/spapr_pci.c
index 97d417a..47ba5ff 100644
--- a/hw/spapr_pci.c
+++ b/hw/spapr_pci.c
@@ -266,12 +266,21 @@ static const MemoryRegionOps spapr_io_ops = {
 /*
  * PHB PCI device
  */
+static DMAContext *spapr_pci_dma_context_fn(PCIBus *bus, void *opaque,
+                                            int devfn)
+{
+    sPAPRPHBState *phb = opaque;
+
+    return phb->dma;
+}
+
 static int spapr_phb_init(SysBusDevice *s)
 {
     sPAPRPHBState *phb = FROM_SYSBUS(sPAPRPHBState, s);
     char *namebuf;
     int i;
     PCIBus *bus;
+    uint32_t liobn;
 
     phb->dtbusname = g_strdup_printf("pci@%" PRIx64, phb->buid);
     namebuf = alloca(strlen(phb->dtbusname) + 32);
@@ -312,6 +321,10 @@ static int spapr_phb_init(SysBusDevice *s)
                            PCI_DEVFN(0, 0), PCI_NUM_PINS);
     phb->host_state.bus = bus;
 
+    liobn = SPAPR_PCI_BASE_LIOBN | (pci_find_domain(bus) << 16);
+    phb->dma = spapr_tce_new_dma_context(liobn, 0x40000000);
+    pci_setup_iommu(bus, spapr_pci_dma_context_fn, phb);
+
     QLIST_INSERT_HEAD(&spapr->phbs, phb, list);
 
     /* Initialize the LSI table */
@@ -472,6 +485,8 @@ int spapr_populate_pci_devices(sPAPRPHBState *phb,
     _FDT(fdt_setprop(fdt, bus_off, "interrupt-map", &interrupt_map,
                      sizeof(interrupt_map)));
 
+    spapr_dma_dt(fdt, bus_off, "ibm,dma-window", phb->dma);
+
     return 0;
 }