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Re: [PATCH 00/13] VIRTIO-IOMMU/VFIO: Don't assume 64b IOVA space
From: |
Eric Auger |
Subject: |
Re: [PATCH 00/13] VIRTIO-IOMMU/VFIO: Don't assume 64b IOVA space |
Date: |
Tue, 5 Sep 2023 11:15:43 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 |
Hi Yanghang,
On 9/5/23 10:22, YangHang Liu wrote:
> I have runned the following two tests, but both tests failed:
> [1] start a VM with virtio-iommu + 2 ice PFs only via qemu-kvm 8.1.5
> Test result : the qemu-kvm keeps throwing the error: VFIO_MAP_DMA
> failed: File exists. vfio_dma_map(0x56443d20fbe0, 0xffffe000, 0x1000,
> 0x7fb545709000) = -17 (File exists)
> [2] start a VM with virtio-iommu + 2 ice PFs via libvirt-9.5 + qemu-kvm 8.1.5
> Test result: the qemu-kvm core dump with
> ERROR:../qom/object.c:1198:object_unref: assertion failed: (obj->ref >
> 0). Bail out! ERROR:../qom/object.c:1198:object_unref: assertion
> failed: (obj->ref > 0)
>
> After removing the 2 PF from the VM, both tests passed.
> Tested-by: Yanghang Liu <yanghliu@redhat.com>
thank you for testing. If my understanding is correct you still
encountered some issues with/after the series. If this is correct you
shall not offer your Tested-by which means you tested the series and it
works fine for you/fixes your issue.
Coming back to the above mentionned issues:
1) the File Exists issue is known and is linked to the replay. This will
be handled separately, ie.I need to resume working on it as my first
approach was flawed: See
https://lore.kernel.org/all/20221207133646.635760-1-eric.auger@redhat.com/
This is unrelated to this series. Note this shouldn't prevent your
passthroughed device from working. Those should be just spurious
warnings that need to be removed.
2) the object_unref assertion most probaly is linked to that series and
I will to investigate asap.
Thank you again!
Eric
>
> Best Regards,
> YangHang Liu
>
>
> On Mon, Sep 4, 2023 at 4:08 PM Eric Auger <eric.auger@redhat.com> wrote:
>> 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/virtio-iommu_geometry_v1
>>
>> 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
>> virtio-iommu: Introduce per IOMMUDevice reserved regions
>> range: Introduce range_inverse_array()
>> virtio-iommu: Implement set_iova_ranges() callback
>> range: Make range_compare() public
>> util/reserved-region: Add new ReservedRegion helpers
>> virtio-iommu: Consolidate host reserved regions and property set ones
>> test: Add some tests for range and resv-mem helpers
>> virtio-iommu: Resize memory region according to the max iova info
>> vfio: Remove 64-bit IOVA address space assumption
>>
>> include/exec/memory.h | 30 ++++-
>> include/hw/vfio/vfio-common.h | 2 +
>> include/hw/virtio/virtio-iommu.h | 7 +-
>> include/qemu/range.h | 9 ++
>> include/qemu/reserved-region.h | 32 +++++
>> hw/core/qdev-properties-system.c | 9 +-
>> hw/vfio/common.c | 70 ++++++++---
>> hw/virtio/virtio-iommu-pci.c | 8 +-
>> hw/virtio/virtio-iommu.c | 85 +++++++++++--
>> softmmu/memory.c | 15 +++
>> tests/unit/test-resv-mem.c | 198 +++++++++++++++++++++++++++++++
>> util/range.c | 41 ++++++-
>> util/reserved-region.c | 94 +++++++++++++++
>> hw/virtio/trace-events | 1 +
>> tests/unit/meson.build | 1 +
>> util/meson.build | 1 +
>> 16 files changed, 562 insertions(+), 41 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 07/13] virtio-iommu: Implement set_iova_ranges() callback, (continued)
- [PATCH 07/13] virtio-iommu: Implement set_iova_ranges() callback, Eric Auger, 2023/09/04
- [PATCH 09/13] util/reserved-region: Add new ReservedRegion helpers, Eric Auger, 2023/09/04
- [PATCH 11/13] test: Add some tests for range and resv-mem helpers, Eric Auger, 2023/09/04
- [PATCH 13/13] vfio: Remove 64-bit IOVA address space assumption, Eric Auger, 2023/09/04
- [PATCH 12/13] virtio-iommu: Resize memory region according to the max iova info, Eric Auger, 2023/09/04
- [PATCH 08/13] range: Make range_compare() public, Eric Auger, 2023/09/04
- [PATCH 10/13] virtio-iommu: Consolidate host reserved regions and property set ones, Eric Auger, 2023/09/04
- Re: [PATCH 00/13] VIRTIO-IOMMU/VFIO: Don't assume 64b IOVA space, YangHang Liu, 2023/09/05
- Re: [PATCH 00/13] VIRTIO-IOMMU/VFIO: Don't assume 64b IOVA space, Alex Williamson, 2023/09/05