[RFC PATCH 00/15] iommu/riscv: Add irqbypass support

Andrew Jones
2024-11-14T16:19:01Z

Platforms with implementations of the RISC-V IOMMU and AIA support
directly delivering MSIs of devices assigned to guests to the VCPUs.
VFIO and KVM have a framework to enable such support, which is called
irqbypass. This series enables irqbypass for devices assigned to KVM
guests when all VCPUs are allocated guest interrupt files. The RISC-V
IOMMU and AIA also support MRIFs (memory-resident interrupt files),
but support for those will be posted as a follow-on to this series.

The patches are organized as follows:
1-3: Prepare to create an MSI remapping irqdomain parented by the IMSIC
4-6: Prepare the IOMMU driver for VFIO domains which will use a single
stage of translation, but G-stage instead of the first stage
7-8: Add support to the IOMMU driver for creating irqdomains
9-10: Prepare KVM to enable irqbypass
11-13: Add irqbypass support to the IOMMU driver and KVM
14-15: Enable VFIO by default

This series is also available here [1] and may be tested with QEMU recent
enough to have the IOMMU model.

Based on linux-next commit 28955f4fa282 ("Add linux-next specific files for 20241112")

[1] https://github.com/jones-drew/linux/commits/riscv/iommu-irqbypass-rfc-v1/

Thanks,
drew

Andrew Jones (10):
irqchip/riscv-imsic: Use hierarchy to reach irq_set_affinity
genirq/msi: Provide DOMAIN_BUS_MSI_REMAP
irqchip/riscv-imsic: Add support for DOMAIN_BUS_MSI_REMAP
iommu/riscv: Move definitions to iommu.h
iommu/riscv: Add IRQ domain for interrupt remapping
RISC-V: KVM: Add irqbypass skeleton
RISC-V: Define irqbypass vcpu_info
iommu/riscv: Add guest file irqbypass support
RISC-V: KVM: Add guest file irqbypass support
RISC-V: defconfig: Add VFIO modules

Tomasz Jeznach (3):
iommu/riscv: report iommu capabilities
RISC-V: KVM: Enable KVM_VFIO interfaces on RISC-V arch
vfio: enable IOMMU_TYPE1 for RISC-V

Zong Li (2):
iommu/riscv: use data structure instead of individual values
iommu/riscv: support GSCID and GVMA invalidation command

arch/riscv/configs/defconfig | 2 +
arch/riscv/include/asm/irq.h | 9 +
arch/riscv/include/asm/kvm_host.h | 3 +
arch/riscv/kvm/Kconfig | 3 +
arch/riscv/kvm/aia_imsic.c | 136 +++++++-
arch/riscv/kvm/vm.c | 60 ++++
drivers/iommu/riscv/Makefile | 2 +-
drivers/iommu/riscv/iommu-bits.h | 11 +
drivers/iommu/riscv/iommu-ir.c | 360 +++++++++++++++++++++
drivers/iommu/riscv/iommu.c | 183 ++++++-----
drivers/iommu/riscv/iommu.h | 78 +++++
drivers/irqchip/irq-riscv-imsic-platform.c | 18 +-
drivers/vfio/Kconfig | 2 +-
include/linux/irqdomain_defs.h | 1 +
14 files changed, 776 insertions(+), 92 deletions(-)
create mode 100644 drivers/iommu/riscv/iommu-ir.c

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2.47.0