On Wed, Sep 20, 2023 at 07:37:53PM +0200, Eric Auger wrote: > >> qemu will typically not be able to > >> self-open /dev/iommufd as it is root-only. > > > > I don't understand, we open multiple fds to KVM devices. This is the > > same. > Actually qemu opens the /dev/iommu in case no fd is passed along with > the iommufd object. This is done in > [PATCH v1 16/22] backends/iommufd: Introduce the iommufd object, in > > iommufd_backend_connect(). I don't understand either.
The char dev node is root only so this automatic behvaior is fine but not useful if qmeu is running in a sandbox. I'm not sure what "multiple fds to KVM devices" means, I don't know anything about kvm devices.. The iommufd design requires one open of the /dev/iommu to be shared across all the vfios. Jason
