>-----Original Message-----
>From: Eric Auger <eric.au...@redhat.com>
>Sent: Thursday, July 6, 2023 12:51 AM
>Subject: [PATCH v2 1/2] virtio-iommu: Fix 64kB host page size VFIO device
>assignment
>
>When running on a 64kB page size host and protecting a VFIO device with the
>virtio-iommu, qemu crashes with this kind of message:
>
>qemu-kvm: virtio-iommu page mask 0xfffffffffffff000 is incompatible with
>mask 0x20010000
>qemu: hardware error: vfio: DMA mapping failed, unable to continue
>
>This is due to the fact the IOMMU MR corresponding to the VFIO device is
>enabled very late on domain attach, after the machine init.
>The device reports a minimal 64kB page size but it is too late to be applied.
>virtio_iommu_set_page_size_mask() fails and this causes
>vfio_listener_region_add() to end up with hw_error();
>
>To work around this issue, we transiently enable the IOMMU MR on machine
>init to collect the page size requirements and then restore the bypass state.
>
>Fixes: 90519b9053 ("virtio-iommu: Add bypass mode support to assigned
>device")
>Signed-off-by: Eric Auger <eric.au...@redhat.com>Reviewed-by: Zhenzhong Duan <zhenzhong.d...@intel.com> Thanks Zhenzhong
