On Tue, Sep 17, 2019 at 03:51:39PM +0000, Derrick, Jonathan wrote: [...] > Sorry for the confusion. > > These changes only affect systems with VMD devices with 8086:28C0 > device IDs, but these won't be production hardware for some time. > > Systems with VMD devices exist in the wild with 8086:201D device IDs. > These don't support the guest passthrough mode and this code won't > break anything with them. Additionally, patch 1/2 (bus numbering) only > affects 8086:28C0. > > So on existing HW, these patches won't affect anything It is me who created confusion, apologies. I read the code properly and I understand that both patches are fixes for HW that is still not available (and they can't create an issue with current kernel because HAS_MEMBAR_SHADOW and HAS_BUS_RESTRICTIONS features are not implemented on 8086:201D), we should take these patches and trickle them to stable kernels as soon as possible so that when HW _is_ available mainline and stable kernels are fixed. Correct ? Lorenzo
