Hi,
Changes from v5:
https://lore.kernel.org/qemu-devel/20260519103727.899332-1-skolothumtho@nvidia.com/
- Addressed v5 feedback and picked up Reviewed-by tags. Thanks!
- Added documentation for design and lifecycle details. Please see patch #30.
- Changed probe() and alloc_viommu() CMDQV ops both mandatory (patches #6, #8)
- Fixed build on windows failure (patch #11)
- Improved tracing with "Direct" vs "VI" info (patches #15, #16)
- Removed vcmdq_enabled() check on BASE reprogramming (patch #16)
- Dropped address_space_range_is_ram() check; record error on setup_vcmdq()
failure (patch #18)
- Dropped qemu_ram_backend_pagesize_min() and instead uses
qemu_minrampagesize()- patch #25
- Based on top of Nathan's "Resolve AUTO properties" v4 series [0].
Please find the complete branch here:
https://github.com/shamiali2008/qemu-master/tree/master-vcmdq-v6-ext
Sanity tested on NVIDIA Grace. Further testing in progress.
Feedback and testing are very welcome.
Thanks,
Shameer
[0] https://lore.kernel.org/qemu-devel/20260527221631.612026-1-nathanc@nvidia.com/
---
Background(from RFCv1):
https://lore.kernel.org/qemu-devel/20251210133737.78257-1-skolothumtho@nvidia.com/
Thanks to Nicolin for the initial patches and testing on which this
is based.
Tegra241 CMDQV extends SMMUv3 by allocating per-VM "virtual interfaces"
(VINTFs), each hosting up to 128 VCMDQs.
Each VINTF exposes two 64KB MMIO pages:
- Page0 – guest owned control and status registers (directly mapped
into the VM)
- Page1 – queue configuration registers (trapped/emulated by QEMU)
Unlike the standard SMMU CMDQ, a guest owned Tegra241 VCMDQ does not
support the full command set. Only a subset, primarily invalidation
related commands, is accepted by the CMDQV hardware. For this reason,
a distinct CMDQV device must be exposed to the guest, and the guest OS
must include a Tegra241 CMDQV aware driver to take advantage of the
hardware acceleration.
VCMDQ support is integrated via the IOMMU_HW_QUEUE_ALLOC mechanism,
allowing QEMU to attach guest configured VCMDQ buffers to the
underlying CMDQV hardware through IOMMUFD. The Linux kernel already
supports the full CMDQV virtualisation model via IOMMUFD[0].
---
Nicolin Chen (15):
backends/iommufd: Update iommufd_backend_get_device_info
backends/iommufd: Update iommufd_backend_alloc_viommu to allow user
ptr
backends/iommufd: Introduce iommufd_backend_alloc_hw_queue
backends/iommufd: Introduce iommufd_backend_viommu_mmap
hw/arm/tegra241-cmdqv: Implement CMDQV init
hw/arm/tegra241-cmdqv: Implement CMDQV vIOMMU alloc/free
hw/arm/tegra241-cmdqv: Emulate CMDQ-V Config region
hw/arm/tegra241-cmdqv: Emulate VCMDQ register reads
hw/arm/tegra241-cmdqv: Emulate VCMDQ register writes
hw/arm/tegra241-cmdqv: mmap VINTF Page0 for CMDQV
hw/arm/tegra241-cmdqv: Allocate HW VCMDQs once configured
hw/arm/tegra241-cmdqv: Map VINTF page0 into guest MMIO space
hw/arm/tegra241-cmdqv: Add reset handler
hw/arm/tegra241-cmdqv: Limit queue size based on backend page size
hw/arm/virt-acpi: Advertise Tegra241 CMDQV nodes in DSDT
Shameer Kolothum (16):
system/iommufd: Remove unused viommu pointer from IOMMUFDVeventq
hw/arm/smmuv3-accel: Introduce CMDQV ops interface
hw/arm/tegra241-cmdqv: Add Tegra241 CMDQV ops backend stub
hw/arm/smmuv3-accel: Wire CMDQV ops into accel lifecycle
hw/arm/virt: Use stored SMMUv3 device list for IORT build
hw/arm/tegra241-cmdqv: Probe host Tegra241 CMDQV support
hw/arm/virt: Link SMMUv3 CMDQV resources to platform bus
hw/arm/tegra241-cmdqv: Use mmap'd VINTF page0 as VCMDQ backing
memory: Allow RAM device regions to skip IOMMU mapping
hw/arm/smmuv3-accel: Introduce common helper for veventq read
hw/arm/tegra241-cmdqv: Read and propagate Tegra241 CMDQV errors
hw/arm/smmuv3: Add per-device identifier property
hw/arm/smmuv3-accel: Introduce helper to query CMDQV type
hw/arm/smmuv3-accel: Enforce viommu association when CMDQV is active
hw/arm/tegra241-cmdqv: Document the CMDQV design and lifecycle
hw/arm/smmuv3: Add cmdqv property for SMMUv3 device
hw/arm/smmuv3-accel.h | 48 ++
hw/arm/tegra241-cmdqv.h | 384 +++++++++++
include/hw/arm/smmuv3.h | 3 +
include/hw/arm/virt.h | 1 +
include/system/iommufd.h | 17 +-
include/system/memory.h | 21 +
backends/iommufd.c | 64 ++
hw/arm/smmuv3-accel-stubs.c | 12 +
hw/arm/smmuv3-accel.c | 194 ++++--
hw/arm/smmuv3.c | 10 +
hw/arm/tegra241-cmdqv-stubs.c | 16 +
hw/arm/tegra241-cmdqv.c | 1122 +++++++++++++++++++++++++++++++++
hw/arm/virt-acpi-build.c | 127 ++--
hw/arm/virt.c | 37 ++
hw/vfio/iommufd.c | 4 +-
hw/vfio/listener.c | 6 +
system/memory.c | 10 +
backends/trace-events | 4 +-
hw/arm/Kconfig | 5 +
hw/arm/meson.build | 2 +
hw/arm/trace-events | 11 +
hw/vfio/trace-events | 1 +
qemu-options.hx | 8 +
23 files changed, 2027 insertions(+), 80 deletions(-)
create mode 100644 hw/arm/tegra241-cmdqv.h
create mode 100644 hw/arm/tegra241-cmdqv-stubs.c
create mode 100644 hw/arm/tegra241-cmdqv.c
--
2.43.0