On 7/16/24 11:45, Eric Auger wrote:
> 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().
Fully agree.
> 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>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Thanks,
C.
> ---
> hw/virtio/virtio-iommu.c | 21 ---------------------
> 1 file changed, 21 deletions(-)
>
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
> index 33ae61c4a6..4e34dacd6e 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -467,26 +467,6 @@ static AddressSpace *virtio_iommu_find_add_as(PCIBus *bus, void *opaque,
> return &sdev->as;
> }
>
> -static void virtio_iommu_device_clear(VirtIOIOMMU *s, PCIBus *bus, int devfn)
> -{
> - IOMMUPciBus *sbus = g_hash_table_lookup(s->as_by_busptr, bus);
> - IOMMUDevice *sdev;
> -
> - if (!sbus) {
> - return;
> - }
> -
> - sdev = sbus->pbdev[devfn];
> - if (!sdev) {
> - return;
> - }
> -
> - g_list_free_full(sdev->resv_regions, g_free);
> - sdev->resv_regions = NULL;
> - g_free(sdev);
> - sbus->pbdev[devfn] = NULL;
> -}
> -
> static gboolean hiod_equal(gconstpointer v1, gconstpointer v2)
> {
> const struct hiod_key *key1 = v1;
> @@ -728,7 +708,6 @@ virtio_iommu_unset_iommu_device(PCIBus *bus, void *opaque, int devfn)
> }
>
> g_hash_table_remove(viommu->host_iommu_devices, &key);
> - virtio_iommu_device_clear(viommu, bus, devfn);
> }
>
> static const PCIIOMMUOps virtio_iommu_ops = {