v2: IMS (now dev-msi): With recommendations from Jason/Thomas/Dan on making IMS more generic: Pass a non-pci generic device(struct device) for IMS management instead of mdev Remove all references to mdev and symbol_get/put Remove all references to IMS in common code and replace with dev-msi remove dynamic allocation of platform-msi interrupts: no groups,no new msi list or list helpers Create a generic dev-msi domain with and without interrupt remapping enabled. Introduce dev_msi_domain_alloc_irqs and dev_msi_domain_free_irqs apis mdev: Removing unrelated bits from SVA enabling that’s not necessary for the submission. (Kevin) Restructured entire mdev driver series to make reviewing easier (Kevin) Made rw emulation more robust (Kevin) Removed uuid wq type and added single dedicated wq type (Kevin) Locking fixes for vdev (Yan Zhao) VFIO MSIX trigger fixes (Yan Zhao) Link to previous discussions with Jason: https://lore.kernel.org/lkml/57296ad1-20fe-caf2-b83f-46d823ca0b5f@xxxxxxxxx/ The emulation part that can be moved to user space is very small due to the majority of the emulations being control bits and need to reside in the kernel. We can revisit the necessity of moving the small emulation part to userspace and required architectural changes at a later time. This RFC series has been reviewed by Dan Williams <dan.j.williams@xxxxxxxxx> The actual code can be independent of the stage 2 driver code submission that adds support for SVM, ENQCMD(S), PASID, and shared workqueues. This code series will match the support of the 5.6 kernel (stage 1) driver but on guest. The code is dependent on Baolu’s iommu aux-domain API extensions patches that’s still in process of being reviewed: https://lkml.org/lkml/2020/7/14/48 Stage 1 of the driver has been accepted in v5.6 kernel. It supports dedicated workqueue (wq) without Shared Virtual Memory (SVM) support. Stage 2 supports shared wq and SVM. It is pending upstream review and targeting kernel v5.9. VFIO mediated device framework allows vendor drivers to wrap a portion of device resources into virtual devices (mdev). Each mdev can be assigned to different guest using the same set of VFIO uAPIs as assigning a physical device. Accessing to the mdev resource is served with mixed policies. For example, vendor drivers typically mark data-path interface as pass-through for fast guest operations, and then trap-and-mediate the control-path interface to avoid undesired interference between mdevs. Some level of emulation is necessary behind vfio mdev to compose the virtual device interface. This series brings mdev to idxd driver to enable Intel Scalable IOV (SIOV), a hardware-assisted mediated pass-through technology. SIOV makes each DSA wq independently assignable through PASID-granular resource/DMA isolation. It helps improve scalability and reduces mediation complexity against purely software-based mdev implementations. Each assigned wq is configured by host and exposed to the guest in a read-only configuration mode, which allows the guest to use the wq w/o additional setup. This design greatly reduces the emulation bits to focus on handling commands from guests. Introducing mdev types “1dwq” type. This mdev type allows allocation of a single dedicated wq from available dedicated wqs. After a workqueue (wq) is enabled, the user will generate an uuid. On mdev creation, the mdev driver code will find a dwq depending on the mdev type. When the create operation is successful, the user generated uuid can be passed to qemu. When the guest boots up, it should discover a DSA device when doing PCI discovery. For example of “1dwq” type: 1. Enable wq with “mdev” wq type 2. A user generated uuid. 3. The uuid is written to the mdev class sysfs path: echo $UUID > /sys/class/mdev_bus/0000\:00\:0a.0/mdev_supported_types/idxd-wq/create 4. Pass the following parameter to qemu: "-device vfio-pci,sysfsdev=/sys/bus/pci/devices/0000:00:0a.0/$UUID" The wq exported through mdev will have the read only config bit set for configuration. This means that the device does not require the typical configuration. After enabling the device, the user must set the WQ type and name. That is all is necessary to enable the WQ and start using it. The single wq configuration is not the only way to create the mdev. Multi wqs support for mdev will be in the future works. The mdev utilizes Interrupt Message Store or IMS[3], a device-specific MSI implementation, instead of MSIX for interrupts for the guest. This preserves MSIX for host usages and also allows a significantly larger number of interrupt vectors for guest usage. The idxd driver implements IMS as on-device memory mapped unified storage. Each interrupt message is stored as a DWORD size data payload and a 64-bit address (same as MSI-X). Access to the IMS is through the host idxd driver. This patchset extends the existing platform-msi framework (which provides a generic mechanism to support non-PCI compliant MSI interrupts) to benefit any driver which wants to allocate msi-like(dev-msi) interrupts and provide its own ops functions (mask/unmask etc.) Call-back functions defined by the kernel and implemented by the driver are used to 1. program the interrupt addr/data values instead of the kernel directly programming them. 2. mask/unmask the interrupt source The kernel can specify the requirements for these callback functions (e.g., the driver is not expected to block, or not expected to take a lock in the callback function). Support for 2 new IRQ chip/domain is added(with and without IRQ_REMAP support- DEV-MSI/IR-DEV-MSI). [1]: https://lore.kernel.org/lkml/157965011794.73301.15960052071729101309.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx/ [2]: https://software.intel.com/en-us/articles/intel-sdm [3]: https://software.intel.com/en-us/download/intel-scalable-io-virtualization-technical-specification [4]: https://software.intel.com/en-us/download/intel-data-streaming-accelerator-preliminary-architecture-specification [5]: https://01.org/blogs/2019/introducing-intel-data-streaming-accelerator [6]: https://intel.github.io/idxd/ [7]: https://github.com/intel/idxd-driver idxd-stage2.5 --- Dave Jiang (13): dmaengine: idxd: add support for readonly config devices dmaengine: idxd: add interrupt handle request support dmaengine: idxd: add DEV-MSI support in base driver dmaengine: idxd: add device support functions in prep for mdev dmaengine: idxd: add basic mdev registration and helper functions dmaengine: idxd: add emulation rw routines dmaengine: idxd: prep for virtual device commands dmaengine: idxd: virtual device commands emulation dmaengine: idxd: ims setup for the vdcm dmaengine: idxd: add mdev type as a new wq type dmaengine: idxd: add dedicated wq mdev type dmaengine: idxd: add new wq state for mdev dmaengine: idxd: add error notification from host driver to mediated device Jing Lin (1): dmaengine: idxd: add ABI documentation for mediated device support Megha Dey (4): platform-msi: Introduce platform_msi_ops irq/dev-msi: Add support for a new DEV_MSI irq domain irq/dev-msi: Create IR-DEV-MSI irq domain irq/dev-msi: Introduce APIs to allocate/free dev-msi interrupts Documentation/ABI/stable/sysfs-driver-dma-idxd | 15 arch/x86/include/asm/hw_irq.h | 6 arch/x86/kernel/apic/msi.c | 12 drivers/base/Kconfig | 7 drivers/base/Makefile | 1 drivers/base/dev-msi.c | 170 ++++ drivers/base/platform-msi.c | 62 + drivers/base/platform-msi.h | 23 drivers/dma/Kconfig | 7 drivers/dma/idxd/Makefile | 2 drivers/dma/idxd/cdev.c | 6 drivers/dma/idxd/device.c | 266 +++++- drivers/dma/idxd/idxd.h | 62 + drivers/dma/idxd/ims.c | 174 ++++ drivers/dma/idxd/ims.h | 17 drivers/dma/idxd/init.c | 100 ++ drivers/dma/idxd/irq.c | 6 drivers/dma/idxd/mdev.c | 1106 ++++++++++++++++++++++++ drivers/dma/idxd/mdev.h | 118 +++ drivers/dma/idxd/registers.h | 24 - drivers/dma/idxd/submit.c | 37 + drivers/dma/idxd/sysfs.c | 55 + drivers/dma/idxd/vdev.c | 962 +++++++++++++++++++++ drivers/dma/idxd/vdev.h | 28 + drivers/dma/mv_xor_v2.c | 6 drivers/dma/qcom/hidma.c | 6 drivers/iommu/arm-smmu-v3.c | 6 drivers/iommu/intel/irq_remapping.c | 11 drivers/irqchip/irq-mbigen.c | 8 drivers/irqchip/irq-mvebu-icu.c | 6 drivers/mailbox/bcm-flexrm-mailbox.c | 6 drivers/perf/arm_smmuv3_pmu.c | 6 include/linux/intel-iommu.h | 1 include/linux/irqdomain.h | 11 include/linux/msi.h | 35 + include/uapi/linux/idxd.h | 2 36 files changed, 3270 insertions(+), 100 deletions(-) create mode 100644 drivers/base/dev-msi.c create mode 100644 drivers/base/platform-msi.h create mode 100644 drivers/dma/idxd/ims.c create mode 100644 drivers/dma/idxd/ims.h create mode 100644 drivers/dma/idxd/mdev.c create mode 100644 drivers/dma/idxd/mdev.h create mode 100644 drivers/dma/idxd/vdev.c create mode 100644 drivers/dma/idxd/vdev.h --
