The original issue I found : After starting a VM which has two ice PFs and a virtio-iommu device, qemu-kvm and VM guest dmesg throw lots of duplicate VFIO_MAP_DMA errors
After testing with Eric's build, the original issue is gone and the Tier1 regression test against ice PF and virtio iommu device gets PASS as well. Tested-by: Yanghang Liu <[email protected]> On Wed, Oct 18, 2023 at 9:45 PM Michael S. Tsirkin <[email protected]> wrote: > > On Wed, Oct 11, 2023 at 07:52:16PM +0200, Eric Auger wrote: > > This applies on top of vfio-next: > > https://github.com/legoater/qemu/, vfio-next branch > > virtio things make sense > > Reviewed-by: Michael S. Tsirkin <[email protected]> > > let me know how you want to merge all this. > > > > > 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/vfio-next-iommu_geometry-v3 > > > > History: > > 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 (13): > > 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 > > vfio: Remove 64-bit IOVA address space assumption > > > > include/exec/memory.h | 34 +++- > > include/hw/vfio/vfio-common.h | 2 + > > 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 | 23 ++- > > hw/vfio/container.c | 67 ++++++- > > 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, 791 insertions(+), 46 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 > >
