From: Eric Auger <eric.au...@redhat.com> Add a hotplug handler for virtio-iommu on x86 and set the necessary reserved region property. On x86, the [0xfee00000, 0xfeefffff] DMA region is reserved for MSIs. DMA transactions to this range either trigger IRQ remapping in the IOMMU or bypasses IOMMU translation.
Although virtio-iommu does not support IRQ remapping it must be informed of the reserved region so that it can forward DMA transactions targeting this region. Signed-off-by: Eric Auger <eric.au...@redhat.com> Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org> --- hw/i386/pc.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 694fc9ce07..c1e1cffe16 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -797,6 +797,11 @@ void pc_machine_done(Notifier *notifier, void *data) "irqchip support."); exit(EXIT_FAILURE); } + + if (pcms->virtio_iommu && x86_iommu_get_default()) { + error_report("QEMU does not support multiple vIOMMUs for x86 yet."); + exit(EXIT_FAILURE); + } } void pc_guest_info_init(PCMachineState *pcms) @@ -1376,6 +1381,14 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev, } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) || object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) { pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp); + } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) { + /* Declare the reserved MSI region */ + char *resv_prop_str = g_strdup_printf("0xfee00000:0xfeefffff:%d", + VIRTIO_IOMMU_RESV_MEM_T_MSI); + + qdev_prop_set_uint32(dev, "len-reserved-regions", 1); + qdev_prop_set_string(dev, "reserved-regions[0]", resv_prop_str); + g_free(resv_prop_str); } } @@ -1393,6 +1406,11 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev, PCMachineState *pcms = PC_MACHINE(hotplug_dev); PCIDevice *pdev = PCI_DEVICE(dev); + if (pcms->virtio_iommu) { + error_setg(errp, + "QEMU does not support multiple vIOMMUs for x86 yet."); + return; + } pcms->virtio_iommu = true; pcms->virtio_iommu_bdf = pci_get_bdf(pdev); } @@ -1436,7 +1454,8 @@ static HotplugHandler *pc_get_hotplug_handler(MachineState *machine, if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) || object_dynamic_cast(OBJECT(dev), TYPE_CPU) || object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) || - object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) { + object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI) || + object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) { return HOTPLUG_HANDLER(machine); } -- 2.33.0