qemu /
qemu /
935c3914184c4ebb1a4c545fc77fe2f0b24645c2 Revert "virtio-iommu: Clear IOMMUDevice when VFIO device is unplugged"
This reverts commit 1b889d6e39c32d709f1114699a014b381bcf1cb1.
There are different problems with that tentative fix:
- Some resources are left dangling (resv_regions,
host_resv_ranges) and memory subregions are left attached to
the root MR although freed as embedded in the sdev IOMMUDevice.
Finally the sdev->as is not destroyed and associated listeners
are left.
- Even when fixing the above we observe a memory corruption
associated with the deallocation of the IOMMUDevice. This can
be observed when a VFIO device is hotplugged, hot-unplugged
and a system reset is issued. At this stage we have not been
able to identify the root cause (IOMMU MR or as structs beeing
overwritten and used later on?).
- Another issue is HostIOMMUDevice are indexed by non aliased
BDF whereas the IOMMUDevice is indexed by aliased BDF - yes the
current naming is really misleading -. Given the state of the
code I don't think the virtio-iommu device works in non
singleton group case though.
So let's revert the patch for now. This means the IOMMU MR/as survive
the hotunplug. This is what is done in the intel_iommu for instance.
It does not sound very logical to keep those but currently there is
no symetric function to pci_device_iommu_address_space().
probe_done issue will be handled in a subsequent patch. Also
resv_regions and host_resv_regions will be deallocated separately.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Message-Id: <20240716094619.1713905-2-eric.auger@redhat.com>
Tested-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
1 file changed
