Re: [Qemu-devel] [PATCH 27/30] pci: use memory core for iommu support

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

On Tue, May 21, 2013 at 12:57:28PM +0200, Paolo Bonzini wrote:
> From: Avi Kivity <avi.kivity@gmail.com>
> 
> Use the new iommu support in the memory core for iommu support.  The only
> user, spapr, is also converted, but it still provides a DMAContext
> interface until the non-PCI bits switch to AddressSpace.
> 
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
> [ Do not calls memory_region_del_subregion() on the device's
>   bus_master_enable_region, it is an alias; return an AddressSpace
>   from the IOMMU hook and remove the destructor hook. - David Gibson ]
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Looks good to me.
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  hw/pci/pci.c                | 46 ++++++++++++++++++++++-----------------------
>  hw/ppc/spapr_pci.c          |  9 +++++----
>  include/hw/pci-host/spapr.h |  1 +
>  include/hw/pci/pci.h        |  4 ++--
>  include/hw/pci/pci_bus.h    |  4 ++--
>  5 files changed, 33 insertions(+), 31 deletions(-)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index c9d585c..9e6bd77 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -279,6 +279,12 @@ int pci_find_domain(const PCIBus *bus)
>      return -1;
>  }
>  
> +static AddressSpace *pci_default_address_space(PCIBus *bus, void *opaque, int devfn)
> +{
> +    /* FIXME: inherit memory region from bus creator */
> +    return &address_space_memory;
> +}
> +
>  static void pci_bus_init(PCIBus *bus, DeviceState *parent,
>                           const char *name,
>                           MemoryRegion *address_space_mem,
> @@ -289,6 +295,7 @@ static void pci_bus_init(PCIBus *bus, DeviceState *parent,
>      bus->devfn_min = devfn_min;
>      bus->address_space_mem = address_space_mem;
>      bus->address_space_io = address_space_io;
> +    pci_setup_iommu(bus, pci_default_address_space, NULL);
>  
>      /* host bridge */
>      QLIST_INIT(&bus->child);
> @@ -786,6 +793,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
>      PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(pci_dev);
>      PCIConfigReadFunc *config_read = pc->config_read;
>      PCIConfigWriteFunc *config_write = pc->config_write;
> +    AddressSpace *dma_as;
>  
>      if (devfn < 0) {
>          for(devfn = bus->devfn_min ; devfn < ARRAY_SIZE(bus->devices);
> @@ -801,21 +809,15 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
>                       PCI_SLOT(devfn), PCI_FUNC(devfn), name, bus->devices[devfn]->name);
>          return NULL;
>      }
> +
>      pci_dev->bus = bus;
> -    if (bus->dma_context_fn) {
> -        pci_dev->dma = bus->dma_context_fn(bus, bus->dma_context_opaque, devfn);
> -    } else {
> -        /* FIXME: Make dma_context_fn use MemoryRegions instead, so this path is
> -         * taken unconditionally */
> -        /* FIXME: inherit memory region from bus creator */
> -        memory_region_init_alias(&pci_dev->bus_master_enable_region, "bus master",
> -                                 get_system_memory(), 0,
> -                                 memory_region_size(get_system_memory()));
> -        memory_region_set_enabled(&pci_dev->bus_master_enable_region, false);
> -        address_space_init(&pci_dev->bus_master_as, &pci_dev->bus_master_enable_region);
> -        pci_dev->dma = g_new(DMAContext, 1);
> -        dma_context_init(pci_dev->dma, &pci_dev->bus_master_as);
> -    }
> +    dma_as = bus->iommu_fn(bus, bus->iommu_opaque, devfn);
> +    memory_region_init_alias(&pci_dev->bus_master_enable_region, "bus master",
> +                             dma_as->root, 0, memory_region_size(dma_as->root));
> +    memory_region_set_enabled(&pci_dev->bus_master_enable_region, false);
> +    address_space_init(&pci_dev->bus_master_as, &pci_dev->bus_master_enable_region);
> +    pci_dev->dma = g_new(DMAContext, 1);
> +    dma_context_init(pci_dev->dma, &pci_dev->bus_master_as);
>  
>      pci_dev->devfn = devfn;
>      pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
> @@ -870,12 +872,10 @@ static void do_pci_unregister_device(PCIDevice *pci_dev)
>      pci_dev->bus->devices[pci_dev->devfn] = NULL;
>      pci_config_free(pci_dev);
>  
> -    if (!pci_dev->bus->dma_context_fn) {
> -        address_space_destroy(&pci_dev->bus_master_as);
> -        memory_region_destroy(&pci_dev->bus_master_enable_region);
> -        g_free(pci_dev->dma);
> -        pci_dev->dma = NULL;
> -    }
> +    address_space_destroy(&pci_dev->bus_master_as);
> +    memory_region_destroy(&pci_dev->bus_master_enable_region);
> +    g_free(pci_dev->dma);
> +    pci_dev->dma = NULL;
>  }
>  
>  static void pci_unregister_io_regions(PCIDevice *pci_dev)
> @@ -2232,10 +2232,10 @@ static void pci_device_class_init(ObjectClass *klass, void *data)
>      k->props = pci_props;
>  }
>  
> -void pci_setup_iommu(PCIBus *bus, PCIDMAContextFunc fn, void *opaque)
> +void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque)
>  {
> -    bus->dma_context_fn = fn;
> -    bus->dma_context_opaque = opaque;
> +    bus->iommu_fn = fn;
> +    bus->iommu_opaque = opaque;
>  }
>  
>  static const TypeInfo pci_device_type_info = {
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index eb64a8f..762db62 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -506,12 +506,11 @@ static const MemoryRegionOps spapr_msi_ops = {
>  /*
>   * PHB PCI device
>   */
> -static DMAContext *spapr_pci_dma_context_fn(PCIBus *bus, void *opaque,
> -                                            int devfn)
> +static AddressSpace *spapr_pci_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>  {
>      sPAPRPHBState *phb = opaque;
>  
> -    return spapr_tce_get_dma(phb->tcet);
> +    return &phb->iommu_as;
>  }
>  
>  static int spapr_phb_init(SysBusDevice *s)
> @@ -651,7 +650,9 @@ static int spapr_phb_init(SysBusDevice *s)
>          fprintf(stderr, "Unable to create TCE table for %s\n", sphb->dtbusname);
>          return -1;
>      }
> -    pci_setup_iommu(bus, spapr_pci_dma_context_fn, sphb);
> +    address_space_init(&sphb->iommu_as, spapr_tce_get_iommu(sphb->tcet),
> +                       sphb->dtbusname);
> +    pci_setup_iommu(bus, spapr_pci_dma_iommu, sphb);
>  
>      QLIST_INSERT_HEAD(&spapr->phbs, sphb, list);
>  
> diff --git a/include/hw/pci-host/spapr.h b/include/hw/pci-host/spapr.h
> index 653dd40..1e23dbf 100644
> --- a/include/hw/pci-host/spapr.h
> +++ b/include/hw/pci-host/spapr.h
> @@ -50,6 +50,7 @@ typedef struct sPAPRPHBState {
>      uint64_t dma_window_start;
>      uint64_t dma_window_size;
>      sPAPRTCETable *tcet;
> +    AddressSpace iommu_as;
>  
>      struct {
>          uint32_t irq;
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index 8d075ab..3a85bce 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -401,9 +401,9 @@ int pci_read_devaddr(Monitor *mon, const char *addr, int *domp, int *busp,
>  
>  void pci_device_deassert_intx(PCIDevice *dev);
>  
> -typedef DMAContext *(*PCIDMAContextFunc)(PCIBus *, void *, int);
> +typedef AddressSpace *(*PCIIOMMUFunc)(PCIBus *, void *, int);
>  
> -void pci_setup_iommu(PCIBus *bus, PCIDMAContextFunc fn, void *opaque);
> +void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque);
>  
>  static inline void
>  pci_set_byte(uint8_t *config, uint8_t val)
> diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
> index 6ee443c..66762f6 100644
> --- a/include/hw/pci/pci_bus.h
> +++ b/include/hw/pci/pci_bus.h
> @@ -10,8 +10,8 @@
>  
>  struct PCIBus {
>      BusState qbus;
> -    PCIDMAContextFunc dma_context_fn;
> -    void *dma_context_opaque;
> +    PCIIOMMUFunc iommu_fn;
> +    void *iommu_opaque;
>      uint8_t devfn_min;
>      pci_set_irq_fn set_irq;
>      pci_map_irq_fn map_irq;
> -- 
> 1.8.1.4
>