On Wed, Sep 04, 2019 at 04:19:33PM +0200, Auger Eric wrote: > Hi Michael, > > On 9/1/19 8:40 AM, Michael S. Tsirkin wrote: > > On Thu, Aug 01, 2019 at 03:49:37PM +0200, Auger Eric wrote: > >> Hi Michael, > >> > >> On 8/1/19 3:06 PM, Michael S. Tsirkin wrote: > >>> 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 meant: instead of retrieving the info through the of_* code you need > >> to interoperate with the module to retrieve the same info and detect > >> when you need to take that path instead of the of one. > > > > The way to do it would be with a quirk, > > and the quirk would not be part of the > > virtio module - it can poke at the device using > > virtio_pci_cfg_cap. > > I got this preliminary quirk function working. However it only works for > a DECLARE_PCI_FIXUP_ENABLE quirk. In an EARLY quirk, the guest crashes > on the first ioread that attempts to read the BAR as mem accesses are > not enabled yet I guess.
This is why I suggested using virtio_pci_cfg_cap. This allows bar access when mem accesses are disabled. > So assuming I get the proper system config data in the device > configuration, the iommu bindings will be set up late. If it all works with a late quirk, then great. If not we can fall back to config cycles. > By the way I have not yet attempted to generate iommu bindings from the > quirk function (job done in drivers/acpi/arm64/iort.c) which does not > sound to be straightforward. > > > >>> > >>> 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. > >> I will do and trace the code. > >>> > >>> > >>>> 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. > >> So if my understanding is correct, at the moment you would accept a DT > >> integration using MMIO. Is that correct? Meanwhile we can prototype your > >> suggestion. > >> > >> Thanks > >> > >> Eric > > > > Right. > > Thank you for the confirmation. However I am not sure Peter will accept > to get the device integrated as a virtio-mmio device and then deprecated > in favor of a virtio-pci device, all the more so work was prepared to > get a PCI integration. Peter? > > Thanks > > Eric > > > >>> > >>> > >>>>> > >>>>>> --- > >>>>>> > >>>>>> 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 > >>>>> > >>>
