Re: [PATCH v2 05/22] hw/pci: modify pci_setup_iommu() to set PCIIOMMUOps

[Auger Eric <eric.auger@redhat.com>]

On 3/30/20 6:24 AM, Liu Yi L wrote:
> This patch modifies pci_setup_iommu() to set PCIIOMMUOps
> instead of setting PCIIOMMUFunc. PCIIOMMUFunc is used to
> get an address space for a PCI device in vendor specific
> way. The PCIIOMMUOps still offers this functionality. But
> using PCIIOMMUOps leaves space to add more iommu related
> vendor specific operations.
> 
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: Peter Xu <peterx@redhat.com>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Yi Sun <yi.y.sun@linux.intel.com>
> Cc: David Gibson <david@gibson.dropbear.id.au>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Reviewed-by: Peter Xu <peterx@redhat.com>
> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> ---
>  hw/alpha/typhoon.c       |  6 +++++-
>  hw/arm/smmu-common.c     |  6 +++++-
>  hw/hppa/dino.c           |  6 +++++-
>  hw/i386/amd_iommu.c      |  6 +++++-
>  hw/i386/intel_iommu.c    |  6 +++++-
>  hw/pci-host/designware.c |  6 +++++-
>  hw/pci-host/pnv_phb3.c   |  6 +++++-
>  hw/pci-host/pnv_phb4.c   |  6 +++++-
>  hw/pci-host/ppce500.c    |  6 +++++-
>  hw/pci-host/prep.c       |  6 +++++-
>  hw/pci-host/sabre.c      |  6 +++++-
>  hw/pci/pci.c             | 12 +++++++-----
>  hw/ppc/ppc440_pcix.c     |  6 +++++-
>  hw/ppc/spapr_pci.c       |  6 +++++-
>  hw/s390x/s390-pci-bus.c  |  8 ++++++--
>  hw/virtio/virtio-iommu.c |  6 +++++-
>  include/hw/pci/pci.h     |  8 ++++++--
>  include/hw/pci/pci_bus.h |  2 +-
>  18 files changed, 90 insertions(+), 24 deletions(-)
> 
> diff --git a/hw/alpha/typhoon.c b/hw/alpha/typhoon.c
> index 1795e2f..f271de1 100644
> --- a/hw/alpha/typhoon.c
> +++ b/hw/alpha/typhoon.c
> @@ -740,6 +740,10 @@ static AddressSpace *typhoon_pci_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &s->pchip.iommu_as;
>  }
>  
> +static const PCIIOMMUOps typhoon_iommu_ops = {
> +    .get_address_space = typhoon_pci_dma_iommu,
> +};
> +
>  static void typhoon_set_irq(void *opaque, int irq, int level)
>  {
>      TyphoonState *s = opaque;
> @@ -897,7 +901,7 @@ PCIBus *typhoon_init(MemoryRegion *ram, ISABus **isa_bus, qemu_irq *p_rtc_irq,
>                               "iommu-typhoon", UINT64_MAX);
>      address_space_init(&s->pchip.iommu_as, MEMORY_REGION(&s->pchip.iommu),
>                         "pchip0-pci");
> -    pci_setup_iommu(b, typhoon_pci_dma_iommu, s);
> +    pci_setup_iommu(b, &typhoon_iommu_ops, s);
>  
>      /* Pchip0 PCI special/interrupt acknowledge, 0x801.F800.0000, 64MB.  */
>      memory_region_init_io(&s->pchip.reg_iack, OBJECT(s), &alpha_pci_iack_ops,
> diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
> index e13a5f4..447146e 100644
> --- a/hw/arm/smmu-common.c
> +++ b/hw/arm/smmu-common.c
> @@ -343,6 +343,10 @@ static AddressSpace *smmu_find_add_as(PCIBus *bus, void *opaque, int devfn)
>      return &sdev->as;
>  }
>  
> +static const PCIIOMMUOps smmu_ops = {
> +    .get_address_space = smmu_find_add_as,
> +};
> +
>  IOMMUMemoryRegion *smmu_iommu_mr(SMMUState *s, uint32_t sid)
>  {
>      uint8_t bus_n, devfn;
> @@ -437,7 +441,7 @@ static void smmu_base_realize(DeviceState *dev, Error **errp)
>      s->smmu_pcibus_by_busptr = g_hash_table_new(NULL, NULL);
>  
>      if (s->primary_bus) {
> -        pci_setup_iommu(s->primary_bus, smmu_find_add_as, s);
> +        pci_setup_iommu(s->primary_bus, &smmu_ops, s);
>      } else {
>          error_setg(errp, "SMMU is not attached to any PCI bus!");
>      }
> diff --git a/hw/hppa/dino.c b/hw/hppa/dino.c
> index 2b1b38c..3da4f84 100644
> --- a/hw/hppa/dino.c
> +++ b/hw/hppa/dino.c
> @@ -459,6 +459,10 @@ static AddressSpace *dino_pcihost_set_iommu(PCIBus *bus, void *opaque,
>      return &s->bm_as;
>  }
>  
> +static const PCIIOMMUOps dino_iommu_ops = {
> +    .get_address_space = dino_pcihost_set_iommu,
> +};
> +
>  /*
>   * Dino interrupts are connected as shown on Page 78, Table 23
>   * (Little-endian bit numbers)
> @@ -580,7 +584,7 @@ PCIBus *dino_init(MemoryRegion *addr_space,
>      memory_region_add_subregion(&s->bm, 0xfff00000,
>                                  &s->bm_cpu_alias);
>      address_space_init(&s->bm_as, &s->bm, "pci-bm");
> -    pci_setup_iommu(b, dino_pcihost_set_iommu, s);
> +    pci_setup_iommu(b, &dino_iommu_ops, s);
>  
>      *p_rtc_irq = qemu_allocate_irq(dino_set_timer_irq, s, 0);
>      *p_ser_irq = qemu_allocate_irq(dino_set_serial_irq, s, 0);
> diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
> index b1175e5..5fec30e 100644
> --- a/hw/i386/amd_iommu.c
> +++ b/hw/i386/amd_iommu.c
> @@ -1451,6 +1451,10 @@ static AddressSpace *amdvi_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &iommu_as[devfn]->as;
>  }
>  
> +static const PCIIOMMUOps amdvi_iommu_ops = {
> +    .get_address_space = amdvi_host_dma_iommu,
> +};
> +
>  static const MemoryRegionOps mmio_mem_ops = {
>      .read = amdvi_mmio_read,
>      .write = amdvi_mmio_write,
> @@ -1577,7 +1581,7 @@ static void amdvi_realize(DeviceState *dev, Error **errp)
>  
>      sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->mmio);
>      sysbus_mmio_map(SYS_BUS_DEVICE(s), 0, AMDVI_BASE_ADDR);
> -    pci_setup_iommu(bus, amdvi_host_dma_iommu, s);
> +    pci_setup_iommu(bus, &amdvi_iommu_ops, s);
>      s->devid = object_property_get_int(OBJECT(&s->pci), "addr", errp);
>      msi_init(&s->pci.dev, 0, 1, true, false, errp);
>      amdvi_init(s);
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index df7ad25..4b22910 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -3729,6 +3729,10 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &vtd_as->as;
>  }
>  
> +static PCIIOMMUOps vtd_iommu_ops = {
static const
> +    .get_address_space = vtd_host_dma_iommu,
> +};
> +
>  static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
>  {
>      X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
> @@ -3840,7 +3844,7 @@ static void vtd_realize(DeviceState *dev, Error **errp)
>                                                g_free, g_free);
>      vtd_init(s);
>      sysbus_mmio_map(SYS_BUS_DEVICE(s), 0, Q35_HOST_BRIDGE_IOMMU_ADDR);
> -    pci_setup_iommu(bus, vtd_host_dma_iommu, dev);
> +    pci_setup_iommu(bus, &vtd_iommu_ops, dev);
>      /* Pseudo address space under root PCI bus. */
>      x86ms->ioapic_as = vtd_host_dma_iommu(bus, s, Q35_PSEUDO_DEVFN_IOAPIC);
>      qemu_add_machine_init_done_notifier(&vtd_machine_done_notify);
> diff --git a/hw/pci-host/designware.c b/hw/pci-host/designware.c
> index dd24551..4c6338a 100644
> --- a/hw/pci-host/designware.c
> +++ b/hw/pci-host/designware.c
> @@ -645,6 +645,10 @@ static AddressSpace *designware_pcie_host_set_iommu(PCIBus *bus, void *opaque,
>      return &s->pci.address_space;
>  }
>  
> +static const PCIIOMMUOps designware_iommu_ops = {
> +    .get_address_space = designware_pcie_host_set_iommu,
> +};
> +
>  static void designware_pcie_host_realize(DeviceState *dev, Error **errp)
>  {
>      PCIHostState *pci = PCI_HOST_BRIDGE(dev);
> @@ -686,7 +690,7 @@ static void designware_pcie_host_realize(DeviceState *dev, Error **errp)
>      address_space_init(&s->pci.address_space,
>                         &s->pci.address_space_root,
>                         "pcie-bus-address-space");
> -    pci_setup_iommu(pci->bus, designware_pcie_host_set_iommu, s);
> +    pci_setup_iommu(pci->bus, &designware_iommu_ops, s);
>  
>      qdev_set_parent_bus(DEVICE(&s->root), BUS(pci->bus));
>      qdev_init_nofail(DEVICE(&s->root));
> diff --git a/hw/pci-host/pnv_phb3.c b/hw/pci-host/pnv_phb3.c
> index 74618fa..ecfe627 100644
> --- a/hw/pci-host/pnv_phb3.c
> +++ b/hw/pci-host/pnv_phb3.c
> @@ -961,6 +961,10 @@ static AddressSpace *pnv_phb3_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &ds->dma_as;
>  }
>  
> +static PCIIOMMUOps pnv_phb3_iommu_ops = {
static const
> +    .get_address_space = pnv_phb3_dma_iommu,
> +};
> +
>  static void pnv_phb3_instance_init(Object *obj)
>  {
>      PnvPHB3 *phb = PNV_PHB3(obj);
> @@ -1059,7 +1063,7 @@ static void pnv_phb3_realize(DeviceState *dev, Error **errp)
>                                       &phb->pci_mmio, &phb->pci_io,
>                                       0, 4, TYPE_PNV_PHB3_ROOT_BUS);
>  
> -    pci_setup_iommu(pci->bus, pnv_phb3_dma_iommu, phb);
> +    pci_setup_iommu(pci->bus, &pnv_phb3_iommu_ops, phb);
>  
>      /* Add a single Root port */
>      qdev_prop_set_uint8(DEVICE(&phb->root), "chassis", phb->chip_id);
> diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
> index 23cf093..04e95e3 100644
> --- a/hw/pci-host/pnv_phb4.c
> +++ b/hw/pci-host/pnv_phb4.c
> @@ -1148,6 +1148,10 @@ static AddressSpace *pnv_phb4_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &ds->dma_as;
>  }
>  
> +static PCIIOMMUOps pnv_phb4_iommu_ops = {
idem
> +    .get_address_space = pnv_phb4_dma_iommu,
> +};
> +
>  static void pnv_phb4_instance_init(Object *obj)
>  {
>      PnvPHB4 *phb = PNV_PHB4(obj);
> @@ -1205,7 +1209,7 @@ static void pnv_phb4_realize(DeviceState *dev, Error **errp)
>                                       pnv_phb4_set_irq, pnv_phb4_map_irq, phb,
>                                       &phb->pci_mmio, &phb->pci_io,
>                                       0, 4, TYPE_PNV_PHB4_ROOT_BUS);
> -    pci_setup_iommu(pci->bus, pnv_phb4_dma_iommu, phb);
> +    pci_setup_iommu(pci->bus, &pnv_phb4_iommu_ops, phb);
>  
>      /* Add a single Root port */
>      qdev_prop_set_uint8(DEVICE(&phb->root), "chassis", phb->chip_id);
> diff --git a/hw/pci-host/ppce500.c b/hw/pci-host/ppce500.c
> index d710727..5baf5db 100644
> --- a/hw/pci-host/ppce500.c
> +++ b/hw/pci-host/ppce500.c
> @@ -439,6 +439,10 @@ static AddressSpace *e500_pcihost_set_iommu(PCIBus *bus, void *opaque,
>      return &s->bm_as;
>  }
>  
> +static const PCIIOMMUOps ppce500_iommu_ops = {
> +    .get_address_space = e500_pcihost_set_iommu,
> +};
> +
>  static void e500_pcihost_realize(DeviceState *dev, Error **errp)
>  {
>      SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
> @@ -473,7 +477,7 @@ static void e500_pcihost_realize(DeviceState *dev, Error **errp)
>      memory_region_init(&s->bm, OBJECT(s), "bm-e500", UINT64_MAX);
>      memory_region_add_subregion(&s->bm, 0x0, &s->busmem);
>      address_space_init(&s->bm_as, &s->bm, "pci-bm");
> -    pci_setup_iommu(b, e500_pcihost_set_iommu, s);
> +    pci_setup_iommu(b, &ppce500_iommu_ops, s);
>  
>      pci_create_simple(b, 0, "e500-host-bridge");
>  
> diff --git a/hw/pci-host/prep.c b/hw/pci-host/prep.c
> index 1a02e9a..7c57311 100644
> --- a/hw/pci-host/prep.c
> +++ b/hw/pci-host/prep.c
> @@ -213,6 +213,10 @@ static AddressSpace *raven_pcihost_set_iommu(PCIBus *bus, void *opaque,
>      return &s->bm_as;
>  }
>  
> +static const PCIIOMMUOps raven_iommu_ops = {
> +    .get_address_space = raven_pcihost_set_iommu,
> +};
> +
>  static void raven_change_gpio(void *opaque, int n, int level)
>  {
>      PREPPCIState *s = opaque;
> @@ -303,7 +307,7 @@ static void raven_pcihost_initfn(Object *obj)
>      memory_region_add_subregion(&s->bm, 0         , &s->bm_pci_memory_alias);
>      memory_region_add_subregion(&s->bm, 0x80000000, &s->bm_ram_alias);
>      address_space_init(&s->bm_as, &s->bm, "raven-bm");
> -    pci_setup_iommu(&s->pci_bus, raven_pcihost_set_iommu, s);
> +    pci_setup_iommu(&s->pci_bus, &raven_iommu_ops, s);
>  
>      h->bus = &s->pci_bus;
>  
> diff --git a/hw/pci-host/sabre.c b/hw/pci-host/sabre.c
> index 2b8503b..251549b 100644
> --- a/hw/pci-host/sabre.c
> +++ b/hw/pci-host/sabre.c
> @@ -112,6 +112,10 @@ static AddressSpace *sabre_pci_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &is->iommu_as;
>  }
>  
> +static const PCIIOMMUOps sabre_iommu_ops = {
> +    .get_address_space = sabre_pci_dma_iommu,
> +};
> +
>  static void sabre_config_write(void *opaque, hwaddr addr,
>                                 uint64_t val, unsigned size)
>  {
> @@ -402,7 +406,7 @@ static void sabre_realize(DeviceState *dev, Error **errp)
>      /* IOMMU */
>      memory_region_add_subregion_overlap(&s->sabre_config, 0x200,
>                      sysbus_mmio_get_region(SYS_BUS_DEVICE(s->iommu), 0), 1);
> -    pci_setup_iommu(phb->bus, sabre_pci_dma_iommu, s->iommu);
> +    pci_setup_iommu(phb->bus, &sabre_iommu_ops, s->iommu);
>  
>      /* APB secondary busses */
>      pci_dev = pci_create_multifunction(phb->bus, PCI_DEVFN(1, 0), true,
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index e1ed667..aa9025c 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -2644,7 +2644,7 @@ AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
>      PCIBus *iommu_bus = bus;
>      uint8_t devfn = dev->devfn;
>  
> -    while (iommu_bus && !iommu_bus->iommu_fn && iommu_bus->parent_dev) {
> +    while (iommu_bus && !iommu_bus->iommu_ops && iommu_bus->parent_dev) {
Depending on future usage, this is not strictly identical to the
original code. You exit the loop as soon as a iommu_bus->iommu_ops is
set whatever the presence of get_address_space().

>          PCIBus *parent_bus = pci_get_bus(iommu_bus->parent_dev);
>  
>          /*
> @@ -2683,15 +2683,17 @@ AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
>  
>          iommu_bus = parent_bus;
>      }
> -    if (iommu_bus && iommu_bus->iommu_fn) {
> -        return iommu_bus->iommu_fn(bus, iommu_bus->iommu_opaque, devfn);
> +    if (iommu_bus && iommu_bus->iommu_ops &&
> +                     iommu_bus->iommu_ops->get_address_space) {
> +        return iommu_bus->iommu_ops->get_address_space(bus,
> +                                 iommu_bus->iommu_opaque, devfn);
>      }
>      return &address_space_memory;
>  }
>  
> -void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque)
> +void pci_setup_iommu(PCIBus *bus, const PCIIOMMUOps *ops, void *opaque)
>  {
> -    bus->iommu_fn = fn;
> +    bus->iommu_ops = ops;
>      bus->iommu_opaque = opaque;
>  }
>  
> diff --git a/hw/ppc/ppc440_pcix.c b/hw/ppc/ppc440_pcix.c
> index 2ee2d4f..7b17ee5 100644
> --- a/hw/ppc/ppc440_pcix.c
> +++ b/hw/ppc/ppc440_pcix.c
> @@ -442,6 +442,10 @@ static AddressSpace *ppc440_pcix_set_iommu(PCIBus *b, void *opaque, int devfn)
>      return &s->bm_as;
>  }
>  
> +static const PCIIOMMUOps ppc440_iommu_ops = {
> +    .get_address_space = ppc440_pcix_set_iommu,
> +};
> +
>  /* The default pci_host_data_{read,write} functions in pci/pci_host.c
>   * deny access to registers without bit 31 set but our clients want
>   * this to work so we have to override these here */
> @@ -487,7 +491,7 @@ static void ppc440_pcix_realize(DeviceState *dev, Error **errp)
>      memory_region_init(&s->bm, OBJECT(s), "bm-ppc440-pcix", UINT64_MAX);
>      memory_region_add_subregion(&s->bm, 0x0, &s->busmem);
>      address_space_init(&s->bm_as, &s->bm, "pci-bm");
> -    pci_setup_iommu(h->bus, ppc440_pcix_set_iommu, s);
> +    pci_setup_iommu(h->bus, &ppc440_iommu_ops, s);
>  
>      memory_region_init(&s->container, OBJECT(s), "pci-container", PCI_ALL_SIZE);
>      memory_region_init_io(&h->conf_mem, OBJECT(s), &pci_host_conf_le_ops,
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 709a527..729a1cb 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -771,6 +771,10 @@ static AddressSpace *spapr_pci_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &phb->iommu_as;
>  }
>  
> +static const PCIIOMMUOps spapr_iommu_ops = {
> +    .get_address_space = spapr_pci_dma_iommu,
> +};
> +
>  static char *spapr_phb_vfio_get_loc_code(SpaprPhbState *sphb,  PCIDevice *pdev)
>  {
>      char *path = NULL, *buf = NULL, *host = NULL;
> @@ -1950,7 +1954,7 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
>      memory_region_add_subregion(&sphb->iommu_root, SPAPR_PCI_MSI_WINDOW,
>                                  &sphb->msiwindow);
>  
> -    pci_setup_iommu(bus, spapr_pci_dma_iommu, sphb);
> +    pci_setup_iommu(bus, &spapr_iommu_ops, sphb);
>  
>      pci_bus_set_route_irq_fn(bus, spapr_route_intx_pin_to_irq);
>  
> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
> index ed8be12..c1c3aa4 100644
> --- a/hw/s390x/s390-pci-bus.c
> +++ b/hw/s390x/s390-pci-bus.c
> @@ -635,6 +635,10 @@ static AddressSpace *s390_pci_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>      return &iommu->as;
>  }
>  
> +static const PCIIOMMUOps s390_iommu_ops = {
> +    .get_address_space = s390_pci_dma_iommu,
> +};
> +
>  static uint8_t set_ind_atomic(uint64_t ind_loc, uint8_t to_be_set)
>  {
>      uint8_t ind_old, ind_new;
> @@ -748,7 +752,7 @@ static void s390_pcihost_realize(DeviceState *dev, Error **errp)
>      b = pci_register_root_bus(dev, NULL, s390_pci_set_irq, s390_pci_map_irq,
>                                NULL, get_system_memory(), get_system_io(), 0,
>                                64, TYPE_PCI_BUS);
> -    pci_setup_iommu(b, s390_pci_dma_iommu, s);
> +    pci_setup_iommu(b, &s390_iommu_ops, s);
>  
>      bus = BUS(b);
>      qbus_set_hotplug_handler(bus, OBJECT(dev), &local_err);
> @@ -919,7 +923,7 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
>  
>          pdev = PCI_DEVICE(dev);
>          pci_bridge_map_irq(pb, dev->id, s390_pci_map_irq);
> -        pci_setup_iommu(&pb->sec_bus, s390_pci_dma_iommu, s);
> +        pci_setup_iommu(&pb->sec_bus, &s390_iommu_ops, s);
>  
>          qbus_set_hotplug_handler(BUS(&pb->sec_bus), OBJECT(s), errp);
>  
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
> index 4cee808..fefc24e 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -235,6 +235,10 @@ static AddressSpace *virtio_iommu_find_add_as(PCIBus *bus, void *opaque,
>      return &sdev->as;
>  }
>  
> +static const PCIIOMMUOps virtio_iommu_ops = {
> +    .get_address_space = virtio_iommu_find_add_as,
> +};
> +
>  static int virtio_iommu_attach(VirtIOIOMMU *s,
>                                 struct virtio_iommu_req_attach *req)
>  {
> @@ -682,7 +686,7 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp)
>      s->as_by_busptr = g_hash_table_new_full(NULL, NULL, NULL, g_free);
>  
>      if (s->primary_bus) {
> -        pci_setup_iommu(s->primary_bus, virtio_iommu_find_add_as, s);
> +        pci_setup_iommu(s->primary_bus, &virtio_iommu_ops, s);
>      } else {
>          error_setg(errp, "VIRTIO-IOMMU is not attached to any PCI bus!");
>      }
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index cfedf5a..ffe192d 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -485,10 +485,14 @@ void pci_bus_get_w64_range(PCIBus *bus, Range *range);
>  
>  void pci_device_deassert_intx(PCIDevice *dev);
>  
> -typedef AddressSpace *(*PCIIOMMUFunc)(PCIBus *, void *, int);
> +typedef struct PCIIOMMUOps PCIIOMMUOps;
> +struct PCIIOMMUOps {
> +    AddressSpace * (*get_address_space)(PCIBus *bus,
> +                                void *opaque, int32_t devfn);
> +};
>  
>  AddressSpace *pci_device_iommu_address_space(PCIDevice *dev);
> -void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque);
> +void pci_setup_iommu(PCIBus *bus, const PCIIOMMUOps *iommu_ops, 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 0714f57..c281057 100644
> --- a/include/hw/pci/pci_bus.h
> +++ b/include/hw/pci/pci_bus.h
> @@ -29,7 +29,7 @@ enum PCIBusFlags {
>  struct PCIBus {
>      BusState qbus;
>      enum PCIBusFlags flags;
> -    PCIIOMMUFunc iommu_fn;
> +    const PCIIOMMUOps *iommu_ops;
>      void *iommu_opaque;
>      uint8_t devfn_min;
>      uint32_t slot_reserved_mask;
> 
Thanks

Eric