On Wed, Jul 05, 2023 at 06:51:16PM +0200, Eric Auger wrote: > When assigning a host device and protecting it with the virtio-iommu we may > end up with qemu crashing with > > qemu-kvm: virtio-iommu page mask 0xfffffffffffff000 is incompatible > with mask 0x20010000 > qemu: hardware error: vfio: DMA mapping failed, unable to continue > > This happens if the host features a 64kB page size and constraints > the physical IOMMU to use a 64kB page size. By default 4kB granule is used > by the qemu virtio-iommu device and this latter becomes aware of the 64kB > requirement too late, after the machine init, when the vfio device domain is > attached. virtio_iommu_set_page_size_mask() fails and this causes > vfio_listener_region_add() to end up with hw_error(). Currently the > granule is global to all domains. > > To work around this issue, despite the IOMMU MR may be bypassed, we > transiently enable it on machine init done to get vfio_listener_region_add > and virtio_iommu_set_page_size_mask called ealier, before the domain > attach. That way the page size requirement can be taken into account > before the guest gets started. > > Also get benefit of this series to do some cleanups in some traces > which may confuse the end user.
For both patches: Reviewed-by: Jean-Philippe Brucker <jean-phili...@linaro.org> Tested-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
