Allow instantiating a virtio-iommu device on ACPI systems by adding a Virtual I/O Translation table (VIOT). Enable x86 support for VIOT.
Changes since v2 [1]: * Use acpi_table_begin() and acpi_table_end(). This series now depends on "acpi: refactor error prone build_header() and packed structures usage in ACPI tables" [2] * Dropped ACPI header definitions. * Dropped doc patch, to be revisited later. * Squashed patch 5. * Added tests for q35 and virt machines: patch 6 temporarily enables blob updates (for bisectability), patch 7 adds the two test cases and patches 8-10 add the three reference tables. There is an important caveat at the moment: when virtio-iommu is instantiated, device DMA faults until the guest configures the IOMMU. Firmware is therefore unable to access storage devices and load the bootloader and OS. Upcoming patches will align virtio-iommu with other vIOMMUs and let DMA bypass the IOMMU during boot. In the meantime there are several ways to circumvent the problem: * Use plain old virtio-blk as storage, without enabling the 'iommu_platform' property. DMA from the device bypasses the IOMMU. * Place the storage device behind a PCI bus that bypasses the IOMMU, using the new 'bypass_iommu' bridge property. See docs/bypass-iommu.txt * Use non-PCI storage devices, for example virtio-blk-device on the arm64 virt machine. You can find a description of the VIOT table, which will be included in next ACPI version, here: https://jpbrucker.net/virtio-iommu/viot/viot-v9.pdf [1] https://lore.kernel.org/qemu-devel/20210903143208.2434284-1-jean-phili...@linaro.org/ [2] https://lore.kernel.org/qemu-devel/20210907144814.741785-1-imamm...@redhat.com/ Jean-Philippe Brucker (10): hw/acpi: Add VIOT table hw/arm/virt-acpi-build: Add VIOT table for virtio-iommu hw/arm/virt: Remove device tree restriction for virtio-iommu hw/arm/virt: Reject instantiation of multiple IOMMUs pc: Allow instantiating a virtio-iommu device tests/acpi: allow updates of VIOT expected data files tests/acpi: add test cases for VIOT tests/acpi: add expected VIOT blob for virt machine tests/acpi: add expected DSDT blob for VIOT test on q35 tests/acpi: add expected VIOT blob for q35 machine hw/acpi/viot.h | 13 ++++ include/hw/i386/pc.h | 2 + hw/acpi/viot.c | 112 +++++++++++++++++++++++++++++++++ hw/arm/virt-acpi-build.c | 7 +++ hw/arm/virt.c | 15 +++-- hw/i386/acpi-build.c | 5 ++ hw/i386/pc.c | 28 ++++++++- hw/virtio/virtio-iommu-pci.c | 7 --- tests/qtest/bios-tables-test.c | 39 ++++++++++++ hw/acpi/Kconfig | 4 ++ hw/acpi/meson.build | 1 + hw/arm/Kconfig | 1 + hw/i386/Kconfig | 1 + tests/data/acpi/q35/DSDT.viot | Bin 0 -> 9415 bytes tests/data/acpi/q35/VIOT.viot | Bin 0 -> 112 bytes tests/data/acpi/virt/VIOT | Bin 0 -> 88 bytes 16 files changed, 219 insertions(+), 16 deletions(-) create mode 100644 hw/acpi/viot.h create mode 100644 hw/acpi/viot.c create mode 100644 tests/data/acpi/q35/DSDT.viot create mode 100644 tests/data/acpi/q35/VIOT.viot create mode 100644 tests/data/acpi/virt/VIOT -- 2.33.0
