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[PATCH v4 00/12] VIRTIO-IOMMU/VFIO: Don't assume 64b IOVA space
From: |
Eric Auger |
Subject: |
[PATCH v4 00/12] VIRTIO-IOMMU/VFIO: Don't assume 64b IOVA space |
Date: |
Thu, 19 Oct 2023 15:45:06 +0200 |
On x86, when assigning VFIO-PCI devices protected with virtio-iommu
we encounter the case where the guest tries to map IOVAs beyond 48b
whereas the physical VTD IOMMU only supports 48b. This ends up with
VFIO_MAP_DMA failures at qemu level because at kernel level,
vfio_iommu_iova_dma_valid() check returns false on vfio_map_do_map().
This is due to the fact the virtio-iommu currently unconditionally
exposes an IOVA range of 64b through its config input range fields.
This series removes this assumption by retrieving the usable IOVA
regions through the VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE UAPI when
a VFIO device is attached. This info is communicated to the
virtio-iommu memory region, transformed into the inversed info, ie.
the host reserved IOVA regions. Then those latter are combined with the
reserved IOVA regions set though the virtio-iommu reserved-regions
property. That way, the guest virtio-iommu driver, unchanged, is
able to probe the whole set of reserved regions and prevent any IOVA
belonging to those ranges from beeing used, achieving the original goal.
Best Regards
Eric
This series can be found at:
https://github.com/eauger/qemu/tree/iommu_geometry-v4
History:
v3 -> v4:
- removed nr_iovas (Alex) and droppped last patch (Alex)
- Collected Michael's R-b, Peter's R-b and Yanghang's T-b
v2 -> v3:
- rebase on top of vfio-next (including iommufd prereq)
- take into account IOVA range info capability may not be offered by
old kernel and use nr_iovas = -1 to encode that [Alex]
- use GList * everywhere instead of arrays (in the range_inverse_array)
with the benefice it sorts ranges retrieved from the kernel which are
not garanteed to be sorted. Rework the tests accordingly [Alex]
- Make sure resv_regions GList is build before the probe() [Jean]
per device list is first populated with prop resv regions on
IOMMUDevice creation and then rebuilt on set_iova()
- Add a warning if set_iova builds a valid list after probe was
called [Jean]
- Build host windows on top of IOVA valid ranges if this info can
be retrieved from the kernel. As many windows are created as
valid ranges
v1 -> v2:
- Remove "[PATCH 12/13] virtio-iommu: Resize memory region according
to the max iova info" which causes way too much trouble: trigger
a coredump in vhost, causes duplication of IOMMU notifiers causing
EEXIST vfio_dma_map errors, ... This looks like a bad usage of the
memory API so I prefer removing this from this series. So I was
also obliged to remove the vfio_find_hostwin() check in the case
of an IOMMU.
- Let range_inverse_array() take low/high args instead of hardcoding
0, UINT64_MAX which both complexifies the algo and the tests.
- Move range function description in header.
- Check that if set_iova_ranges is called several times, new resv
regions are included in previous ones
Eric Auger (12):
memory: Let ReservedRegion use Range
memory: Introduce memory_region_iommu_set_iova_ranges
vfio: Collect container iova range info
virtio-iommu: Rename reserved_regions into prop_resv_regions
range: Make range_compare() public
util/reserved-region: Add new ReservedRegion helpers
virtio-iommu: Introduce per IOMMUDevice reserved regions
range: Introduce range_inverse_array()
virtio-iommu: Record whether a probe request has been issued
virtio-iommu: Implement set_iova_ranges() callback
virtio-iommu: Consolidate host reserved regions and property set ones
test: Add some tests for range and resv-mem helpers
include/exec/memory.h | 34 +++-
include/hw/vfio/vfio-common.h | 1 +
include/hw/virtio/virtio-iommu.h | 7 +-
include/qemu/range.h | 14 ++
include/qemu/reserved-region.h | 32 ++++
hw/core/qdev-properties-system.c | 9 +-
hw/vfio/common.c | 9 +
hw/vfio/container.c | 42 +++-
hw/virtio/virtio-iommu-pci.c | 8 +-
hw/virtio/virtio-iommu.c | 155 +++++++++++++--
system/memory.c | 13 ++
tests/unit/test-resv-mem.c | 318 +++++++++++++++++++++++++++++++
util/range.c | 61 +++++-
util/reserved-region.c | 91 +++++++++
hw/virtio/trace-events | 1 +
tests/unit/meson.build | 1 +
util/meson.build | 1 +
17 files changed, 764 insertions(+), 33 deletions(-)
create mode 100644 include/qemu/reserved-region.h
create mode 100644 tests/unit/test-resv-mem.c
create mode 100644 util/reserved-region.c
--
2.41.0
- [PATCH v4 00/12] VIRTIO-IOMMU/VFIO: Don't assume 64b IOVA space,
Eric Auger <=
- [PATCH v4 01/12] memory: Let ReservedRegion use Range, Eric Auger, 2023/10/19
- [PATCH v4 03/12] vfio: Collect container iova range info, Eric Auger, 2023/10/19
- [PATCH v4 02/12] memory: Introduce memory_region_iommu_set_iova_ranges, Eric Auger, 2023/10/19
- [PATCH v4 05/12] range: Make range_compare() public, Eric Auger, 2023/10/19
- [PATCH v4 04/12] virtio-iommu: Rename reserved_regions into prop_resv_regions, Eric Auger, 2023/10/19
- [PATCH v4 06/12] util/reserved-region: Add new ReservedRegion helpers, Eric Auger, 2023/10/19
- [PATCH v4 07/12] virtio-iommu: Introduce per IOMMUDevice reserved regions, Eric Auger, 2023/10/19
- [PATCH v4 09/12] virtio-iommu: Record whether a probe request has been issued, Eric Auger, 2023/10/19
- [PATCH v4 08/12] range: Introduce range_inverse_array(), Eric Auger, 2023/10/19
- [PATCH v4 10/12] virtio-iommu: Implement set_iova_ranges() callback, Eric Auger, 2023/10/19