On 03.08.2021 15:01, Marek Marczykowski-Górecki wrote: > On Tue, Aug 03, 2021 at 02:29:01PM +0200, Jan Beulich wrote: >> On 03.08.2021 14:21, Marek Marczykowski-Górecki wrote: >>> If we would have an option (in >>> toolstack, or Xen) to force interrupt remapping, then indeed when it's >>> broken, PCI passthrough should be refused (or maybe even system should >>> refuse to boot if we'd have something like iommu=intremap=require). But >>> none of those actually exists. >> >> "iommu=force" actually does prevent boot from completing when >> interrupt remapping is available, but then gets turned off for >> some reason. See iommu_setup()'s >> >> bool_t force_intremap = force_iommu && iommu_intremap; > > Ok, then, just setting iommu_intremap=false should do the right thing,
... if "iommu=force" is in use (but not otherwise), ... > if platform_quirks_init() is called somewhere between the above line, > and actual enforcement of iommu=force few lines later. I couldn't > quickly find if that is the case - is it? iommu_setup() -> iommu_hardware_setup() -> iommu_init_ops->setup() (i.e. vtd_setup()) -> platform_quirks_init() Jan
