On 2025/8/22 14:40, Zhenzhong Duan wrote:
Currently we don't support nested translation for passthrough device with emulated device under same PCI bridge, because they require different address space when x-flts=on.In theory, we do support if devices under same PCI bridge are all passthrough devices. But emulated device can be hotplugged under same bridge. To simplify, just forbid passthrough device under PCI bridge no matter if there is, or will be emulated devices under same bridge. This is acceptable because PCIE bridge is more popular than PCI bridge now. Suggested-by: Yi Liu <yi.l....@intel.com> Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com> Reviewed-by: Eric Auger <eric.au...@redhat.com> --- hw/i386/intel_iommu.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index da355bda79..6edd91d94e 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -4341,9 +4341,10 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, return vtd_dev_as; }-static bool vtd_check_hiod(IntelIOMMUState *s, HostIOMMUDevice *hiod,+static bool vtd_check_hiod(IntelIOMMUState *s, VTDHostIOMMUDevice *vtd_hiod, Error **errp) { + HostIOMMUDevice *hiod = vtd_hiod->hiod; HostIOMMUDeviceClass *hiodc = HOST_IOMMU_DEVICE_GET_CLASS(hiod); int ret;@@ -4370,6 +4371,8 @@ static bool vtd_check_hiod(IntelIOMMUState *s, HostIOMMUDevice *hiod,#ifdef CONFIG_IOMMUFD struct HostIOMMUDeviceCaps *caps = &hiod->caps; struct iommu_hw_info_vtd *vtd = &caps->vendor_caps.vtd; + PCIBus *bus = vtd_hiod->bus; + PCIDevice *pdev = pci_find_device(bus, pci_bus_num(bus), vtd_hiod->devfn);
pci_find_device() finds bus pointer with bus_num, this can be avoided as you already have bus pointer. Perhaps this may be done by wrapping bus->devices[devfn] to a helper. Especially, pci_bus_num() may not have the correct bus number at this point.
/* Remaining checks are all stage-1 translation specific */if (!object_dynamic_cast(OBJECT(hiod), TYPE_HOST_IOMMU_DEVICE_IOMMUFD)) { @@ -4392,6 +4395,12 @@ static bool vtd_check_hiod(IntelIOMMUState *s, HostIOMMUDevice *hiod, error_setg(errp, "Stage-1 1GB huge page is unsupported by host IOMMU"); return false; } + + if (pci_device_get_iommu_bus_devfn(pdev, &bus, NULL, NULL)) { + error_setg(errp, "Host device under PCI bridge is unsupported " + "when x-flts=on"); + return false; + } #endiferror_setg(errp, "host IOMMU is incompatible with stage-1 translation");@@ -4425,7 +4434,7 @@ static bool vtd_dev_set_iommu_device(PCIBus *bus, void *opaque, int devfn, vtd_hiod->iommu_state = s; vtd_hiod->hiod = hiod;- if (!vtd_check_hiod(s, hiod, errp)) {+ if (!vtd_check_hiod(s, vtd_hiod, errp)) { g_free(vtd_hiod); vtd_iommu_unlock(s); return false;
other parts looks good to me. Reviewed-by: Yi Liu <yi.l....@intel.com>
