Hi Wang, On 3/25/21 8:22 AM, Wang Xingang wrote: > From: Xingang Wang <wangxinga...@huawei.com> > > The pci host iommu property is useful to check whether > the iommu is enabled on the pci root bus. > > Signed-off-by: Xingang Wang <wangxinga...@huawei.com> > Signed-off-by: Jiahui Cen <cenjia...@huawei.com> > --- > hw/pci/pci.c | 18 +++++++++++++++++- > hw/pci/pci_host.c | 2 ++ > include/hw/pci/pci.h | 1 + > include/hw/pci/pci_host.h | 1 + > 4 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index ac9a24889c..e17aa9075f 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -417,6 +417,22 @@ const char *pci_root_bus_path(PCIDevice *dev) > return rootbus->qbus.name; > } > > +bool pci_root_bus_has_iommu(PCIBus *bus) "has_iommu" is misleading as it does not mean an IOMMU is actually instantiated but rather that if there is any, it will translate transactions coming from this primary bus
I would rather inverse the logic and have a "bypass_iommu" property defaulting to false and this function dubbed something like pci_root_bus_bypass_iommu > +{ > + PCIBus *rootbus = bus; > + PCIHostState *host_bridge; > + > + if (!pci_bus_is_root(bus)) { > + rootbus = pci_device_root_bus(bus->parent_dev); > + } > + > + host_bridge = PCI_HOST_BRIDGE(rootbus->qbus.parent); > + > + assert(host_bridge->bus == rootbus); > + > + return host_bridge->iommu; > +} > + > static void pci_root_bus_init(PCIBus *bus, DeviceState *parent, > MemoryRegion *address_space_mem, > MemoryRegion *address_space_io, > @@ -2716,7 +2732,7 @@ AddressSpace *pci_device_iommu_address_space(PCIDevice > *dev) > > iommu_bus = parent_bus; > } > - if (iommu_bus && iommu_bus->iommu_fn) { > + if (pci_root_bus_has_iommu(bus) && iommu_bus && iommu_bus->iommu_fn) { > return iommu_bus->iommu_fn(bus, iommu_bus->iommu_opaque, devfn); > } > return &address_space_memory; > diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c > index 8ca5fadcbd..92ce213b18 100644 > --- a/hw/pci/pci_host.c > +++ b/hw/pci/pci_host.c > @@ -222,6 +222,8 @@ const VMStateDescription vmstate_pcihost = { > static Property pci_host_properties_common[] = { > DEFINE_PROP_BOOL("x-config-reg-migration-enabled", PCIHostState, > mig_enabled, true), > + DEFINE_PROP_BOOL("pci-host-iommu-enabled", PCIHostState, > + iommu, true), > DEFINE_PROP_END_OF_LIST(), > }; > > diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h > index 6be4e0c460..718b5a454a 100644 > --- a/include/hw/pci/pci.h > +++ b/include/hw/pci/pci.h > @@ -480,6 +480,7 @@ void pci_for_each_bus(PCIBus *bus, > > PCIBus *pci_device_root_bus(const PCIDevice *d); > const char *pci_root_bus_path(PCIDevice *dev); > +bool pci_root_bus_has_iommu(PCIBus *bus); > PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn); > int pci_qdev_find_device(const char *id, PCIDevice **pdev); > void pci_bus_get_w64_range(PCIBus *bus, Range *range); > diff --git a/include/hw/pci/pci_host.h b/include/hw/pci/pci_host.h > index 52e038c019..64128e3a19 100644 > --- a/include/hw/pci/pci_host.h > +++ b/include/hw/pci/pci_host.h > @@ -43,6 +43,7 @@ struct PCIHostState { > uint32_t config_reg; > bool mig_enabled; > PCIBus *bus; > + bool iommu; > > QLIST_ENTRY(PCIHostState) next; > }; > Thanks Eric