Hi Cédric,
On 11/15/24 09:34, Cédric Le Goater wrote:
> When commit 96b7af4388b3 intoduced a .instance_finalize() handler,
> it did not take into account that the container was not necessarily
> inserted into the container list of the address space. Hence, if
> the container object is destroyed, by calling object_unref() for
> example, before vfio_address_space_insert() is called, QEMU may
> crash when removing the container from the list as done in
> vfio_container_instance_finalize(). This was seen with an SEV-SNP
> guest for which discarding of RAM fails.
>
> To resolve this issue, use the safe version of QLIST_REMOVE().
>
> Cc: Zhenzhong Duan <zhenzhong.d...@intel.com>
> Cc: Eric Auger <eric.au...@redhat.com>
> Fixes: 96b7af4388b3 ("vfio/container: Move vfio_container_destroy() to an
> instance_finalize() handler")
> Signed-off-by: Cédric Le Goater <c...@redhat.com>
Reviewed-by: Eric Auger <eric.au...@redhat.com>
Eric
> ---
>
> Changes in v2:
>
> - use the safe version of QLIST_REMOVE() instead of calling
> vfio_address_space_insert() earlier.
>
> hw/vfio/container-base.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c
> index
> 809b15767425a48f2404b08fc409ee5684af2094..6f86c37d971ec38426dacd471bca837c0d0df806
> 100644
> --- a/hw/vfio/container-base.c
> +++ b/hw/vfio/container-base.c
> @@ -103,7 +103,7 @@ static void vfio_container_instance_finalize(Object *obj)
> VFIOContainerBase *bcontainer = VFIO_IOMMU(obj);
> VFIOGuestIOMMU *giommu, *tmp;
>
> - QLIST_REMOVE(bcontainer, next);
> + QLIST_SAFE_REMOVE(bcontainer, next);
>
> QLIST_FOREACH_SAFE(giommu, &bcontainer->giommu_list, giommu_next, tmp) {
> memory_region_unregister_iommu_notifier(
