On Thu, Aug 01, 2019 at 02:15:03PM +0200, Auger Eric wrote: > Hi Michael, > > On 7/30/19 9:35 PM, Michael S. Tsirkin wrote: > > On Tue, Jul 30, 2019 at 07:21:36PM +0200, Eric Auger wrote: > >> This patch adds virtio-iommu-pci, which is the pci proxy for > >> the virtio-iommu device. > >> > >> Signed-off-by: Eric Auger <eric.au...@redhat.com> > > > > This part I'm not sure we should merge just yet. The reason being I > > think we should limit it to mmio where DT can be used to describe iommu > > topology. For PCI I don't see why we shouldn't always expose this > > in the config space, and I think it's preferable not to > > need to support a mix of DT,ACPI and PCI as options. > > For context, some discussion related to this topic already arose on v7 > revision of the driver: > > [1] Re: [PATCH v7 0/7] Add virtio-iommu driver > https://lore.kernel.org/linux-pci/87a7ioby9u.fsf@morokweng.localdomain/ > > Some additional thoughts. > > First considering DT boot. > > THE DT description features an iommu-map property in the > pci-host-ecam-generic node that describes which RIDs are handled by the > virtio-iommu and a possible offset/mask to be applied inbetween the RID > and the streamID at the input of the IOMMU > (Documentation/devicetree/bindings/pci/pci-iommu.txt) > > As far as I understand when a DMA capable device is setup, its DMA > configuration is built using that call chain: > > pci_dma_configure > |_ of_dma_configure > |_ of_iommu_configure > |_ of_pci_iommu_init > |_ of_map_rid > > I understand you would like the iommu-map/iommu-map-mask info to be > exposed directly into the config space of the device instead of inside > the DT or IORT table. Assuming a module is initialized sufficiently > early to retrieve this info, we would need the resulting info to be > consolidated to allow pci_dma_configure chain to work seemlessly. This > sounds a significant impact on above kernel infrastructure.
I don't really know what consolidated means. It is pretty common for IOMMUs to expose config through PCI registers. This typically happens as a fixup. I would write a tiny driver to do exactly that, and run it from the fixup. > This comes in addition to the development of the "small module that > loads early and pokes at the IOMMU sufficiently to get the data about > which devices use the IOMMU out of it using standard virtio config > space" evoked in [1] + the definition of the data formats to be put in > the very cfg space. That last part is true but that's exactly why I propose we wait on this patch a bit. > With ACPI I understand we have the same kind of infrastructure: > drivers/acpi/arm64/iort.c currently extracts the mapping between RC RIDs > and IOMMU streamids > > pci_dma_configure( > |_ acpi_dma_configure > |_ iort_iommu_configure > |_ iort_pci_iommu_init > |_ iort_node_map_id > |_ iort_id_map > > Maybe I fail to see the easy and right way to do the integration at > kernel level but I am a bit frightened by the efforts that would be > requested to follow your suggestion, whereas the DT infra is ready and > fully upstreamed to accept the use case. Did you take a look at drivers/pci/quirks.c and how these run? I think it's just a question of adding DECLARE_PCI_FIXUP_CLASS_EARLY and running your hook from there. > For ACPI I agree AFAIK IORT was primarily defined by ARM, for ARM but we > prototyped IORT integration with x86 and it worked for pc machine > without major trouble. > > I sent the kernel and qemu patches prototyping this IORT integration: > > https://github.com/eauger/linux/tree/virtio-iommu-v0.9-iort-x86 > https://github.com/eauger/qemu/tree/v3.1.0-rc3-virtio-iommu-v0.9-x86 > > There ACPI IORT was built for PC machine and the integration effort at > both kernel and QEMU level was low. This work would need to be rebased > and depends on kernel ACPI related patches that are not yet upstreamed > though. > > Thanks > > Eric In the end it might turn out you are right. But it does us no harm to delay this just a bit, and for now limit things to ARM where it's already used and where alternatives exist. > > > >> --- > >> > >> v8 -> v9: > >> - add the msi-bypass property > >> - create virtio-iommu-pci.c > >> --- > >> hw/virtio/Makefile.objs | 1 + > >> hw/virtio/virtio-iommu-pci.c | 88 ++++++++++++++++++++++++++++++++ > >> include/hw/pci/pci.h | 1 + > >> include/hw/virtio/virtio-iommu.h | 1 + > >> qdev-monitor.c | 1 + > >> 5 files changed, 92 insertions(+) > >> create mode 100644 hw/virtio/virtio-iommu-pci.c > >> > >> diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs > >> index f42e4dd94f..80ca719f1c 100644 > >> --- a/hw/virtio/Makefile.objs > >> +++ b/hw/virtio/Makefile.objs > >> @@ -27,6 +27,7 @@ obj-$(CONFIG_VIRTIO_INPUT_HOST) += > >> virtio-input-host-pci.o > >> obj-$(CONFIG_VIRTIO_INPUT) += virtio-input-pci.o > >> obj-$(CONFIG_VIRTIO_RNG) += virtio-rng-pci.o > >> obj-$(CONFIG_VIRTIO_BALLOON) += virtio-balloon-pci.o > >> +obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu-pci.o > >> obj-$(CONFIG_VIRTIO_9P) += virtio-9p-pci.o > >> obj-$(CONFIG_VIRTIO_SCSI) += virtio-scsi-pci.o > >> obj-$(CONFIG_VIRTIO_BLK) += virtio-blk-pci.o > >> diff --git a/hw/virtio/virtio-iommu-pci.c b/hw/virtio/virtio-iommu-pci.c > >> new file mode 100644 > >> index 0000000000..f9977096bd > >> --- /dev/null > >> +++ b/hw/virtio/virtio-iommu-pci.c > >> @@ -0,0 +1,88 @@ > >> +/* > >> + * Virtio IOMMU PCI Bindings > >> + * > >> + * Copyright (c) 2019 Red Hat, Inc. > >> + * Written by Eric Auger > >> + * > >> + * This program is free software; you can redistribute it and/or modify > >> + * it under the terms of the GNU General Public License version 2 or > >> + * (at your option) any later version. > >> + */ > >> + > >> +#include "qemu/osdep.h" > >> + > >> +#include "virtio-pci.h" > >> +#include "hw/virtio/virtio-iommu.h" > >> + > >> +typedef struct VirtIOIOMMUPCI VirtIOIOMMUPCI; > >> + > >> +/* > >> + * virtio-iommu-pci: This extends VirtioPCIProxy. > >> + * > >> + */ > >> +#define VIRTIO_IOMMU_PCI(obj) \ > >> + OBJECT_CHECK(VirtIOIOMMUPCI, (obj), TYPE_VIRTIO_IOMMU_PCI) > >> + > >> +struct VirtIOIOMMUPCI { > >> + VirtIOPCIProxy parent_obj; > >> + VirtIOIOMMU vdev; > >> +}; > >> + > >> +static Property virtio_iommu_pci_properties[] = { > >> + DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0), > >> + DEFINE_PROP_BOOL("msi-bypass", VirtIOIOMMUPCI, vdev.msi_bypass, true), > >> + DEFINE_PROP_END_OF_LIST(), > >> +}; > >> + > >> +static void virtio_iommu_pci_realize(VirtIOPCIProxy *vpci_dev, Error > >> **errp) > >> +{ > >> + VirtIOIOMMUPCI *dev = VIRTIO_IOMMU_PCI(vpci_dev); > >> + DeviceState *vdev = DEVICE(&dev->vdev); > >> + > >> + qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus)); > >> + object_property_set_link(OBJECT(dev), > >> + OBJECT(pci_get_bus(&vpci_dev->pci_dev)), > >> + "primary-bus", errp); > >> + object_property_set_bool(OBJECT(vdev), true, "realized", errp); > >> +} > >> + > >> +static void virtio_iommu_pci_class_init(ObjectClass *klass, void *data) > >> +{ > >> + DeviceClass *dc = DEVICE_CLASS(klass); > >> + VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass); > >> + PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass); > >> + k->realize = virtio_iommu_pci_realize; > >> + set_bit(DEVICE_CATEGORY_MISC, dc->categories); > >> + dc->props = virtio_iommu_pci_properties; > >> + pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET; > >> + pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_IOMMU; > >> + pcidev_k->revision = VIRTIO_PCI_ABI_VERSION; > >> + pcidev_k->class_id = PCI_CLASS_OTHERS; > >> +} > >> + > >> +static void virtio_iommu_pci_instance_init(Object *obj) > >> +{ > >> + VirtIOIOMMUPCI *dev = VIRTIO_IOMMU_PCI(obj); > >> + > >> + virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev), > >> + TYPE_VIRTIO_IOMMU); > >> +} > >> + > >> +static const VirtioPCIDeviceTypeInfo virtio_iommu_pci_info = { > >> + .base_name = TYPE_VIRTIO_IOMMU_PCI, > >> + .generic_name = "virtio-iommu-pci", > >> + .transitional_name = "virtio-iommu-pci-transitional", > >> + .non_transitional_name = "virtio-iommu-pci-non-transitional", > >> + .instance_size = sizeof(VirtIOIOMMUPCI), > >> + .instance_init = virtio_iommu_pci_instance_init, > >> + .class_init = virtio_iommu_pci_class_init, > >> +}; > >> + > >> +static void virtio_iommu_pci_register(void) > >> +{ > >> + virtio_pci_types_register(&virtio_iommu_pci_info); > >> +} > >> + > >> +type_init(virtio_iommu_pci_register) > >> + > >> + > >> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h > >> index aaf1b9f70d..492ea7e68d 100644 > >> --- a/include/hw/pci/pci.h > >> +++ b/include/hw/pci/pci.h > >> @@ -86,6 +86,7 @@ extern bool pci_available; > >> #define PCI_DEVICE_ID_VIRTIO_9P 0x1009 > >> #define PCI_DEVICE_ID_VIRTIO_VSOCK 0x1012 > >> #define PCI_DEVICE_ID_VIRTIO_PMEM 0x1013 > >> +#define PCI_DEVICE_ID_VIRTIO_IOMMU 0x1014 > >> > >> #define PCI_VENDOR_ID_REDHAT 0x1b36 > >> #define PCI_DEVICE_ID_REDHAT_BRIDGE 0x0001 > >> diff --git a/include/hw/virtio/virtio-iommu.h > >> b/include/hw/virtio/virtio-iommu.h > >> index 56c8b4e57f..893ac65c0b 100644 > >> --- a/include/hw/virtio/virtio-iommu.h > >> +++ b/include/hw/virtio/virtio-iommu.h > >> @@ -25,6 +25,7 @@ > >> #include "hw/pci/pci.h" > >> > >> #define TYPE_VIRTIO_IOMMU "virtio-iommu-device" > >> +#define TYPE_VIRTIO_IOMMU_PCI "virtio-iommu-device-base" > >> #define VIRTIO_IOMMU(obj) \ > >> OBJECT_CHECK(VirtIOIOMMU, (obj), TYPE_VIRTIO_IOMMU) > >> > >> diff --git a/qdev-monitor.c b/qdev-monitor.c > >> index 58222c2211..74cf090c61 100644 > >> --- a/qdev-monitor.c > >> +++ b/qdev-monitor.c > >> @@ -63,6 +63,7 @@ static const QDevAlias qdev_alias_table[] = { > >> { "virtio-input-host-ccw", "virtio-input-host", QEMU_ARCH_S390X }, > >> { "virtio-input-host-pci", "virtio-input-host", > >> QEMU_ARCH_ALL & ~QEMU_ARCH_S390X }, > >> + { "virtio-iommu-pci", "virtio-iommu", QEMU_ARCH_ALL & > >> ~QEMU_ARCH_S390X }, > >> { "virtio-keyboard-ccw", "virtio-keyboard", QEMU_ARCH_S390X }, > >> { "virtio-keyboard-pci", "virtio-keyboard", > >> QEMU_ARCH_ALL & ~QEMU_ARCH_S390X }, > >> -- > >> 2.20.1 > >
