On 7/9/25 11:16, Jason Andryuk wrote: > Hi, > > I'm running Xen in QEMU with vgic3 and started hitting: > > (XEN) Xen BUG at drivers/passthrough/arm/iommu_helpers.c:49 > > BUG_ON(!is_domain_direct_mapped(d)); > > I'm using dmo0less to create a split hardware and control domains. That > means hwdom is not direct mapped, but is_iommu_enabled() is true. It looks > to be caused by the new call to iommu_map() in: > > commit f9f6b22abf1d8d88c97fbc9925b274c0bb4ac881 > Author: Rahul Singh <rahul.si...@arm.com> > Date: Wed Jul 2 07:10:03 2025 +0000 > > xen/arm: Map ITS doorbell register to IOMMU page tables > > Thoughts on how to address this?
I think the BUG_ON in question wants changing to: - BUG_ON(!is_domain_direct_mapped(d)); + BUG_ON(!domain_use_host_layout(d)); ... along with an appropriate update of the comment prior to this line. I suspect a cache colored hwdom/dom0 would also stumble here. In the future when we will support vITS for domUs, we may want to remove the BUG_ON entirely [1], but for now the ITS doorbell mapping is still expected to be DFN == MFN. [1] https://github.com/Xilinx/xen/commit/d814f9d13a51625bdaca9299d36272ee393e7ddc > Thanks, > Jason > > (XEN) Loading d1 initrd from 0000000045800000 to > 0x0000000048200000-0x000000004bdcd615 > (XEN) Loading d1 DTB to 0x0000000048000000-0x00000000480005c4 > (XEN) Xen BUG at drivers/passthrough/arm/iommu_helpers.c:49 > (XEN) ----[ Xen-4.21-unstable arm64 debug=y Tainted: I ]---- > (XEN) CPU: 0 > (XEN) PC: 00000a000024c758 arm_iommu_map_page+0x80/0x90 > (XEN) LR: 00000a000024c750 > (XEN) SP: 00000a000032fb70 > (XEN) CPSR: 0000000080000249 MODE:64-bit EL2h (Hypervisor, handler) > ... > (XEN) Xen call trace: > (XEN) [<00000a000024c758>] arm_iommu_map_page+0x80/0x90 (PC) > (XEN) [<00000a000024c750>] arm_iommu_map_page+0x78/0x90 (LR) > (XEN) [<00000a0000250884>] iommu_map+0xcc/0x29c > (XEN) [<00000a0000288024>] vgic_v3_its_init_domain+0x18c/0x1e8 > (XEN) [<00000a0000285228>] vgic-v3.c#vgic_v3_domain_init+0x168/0x21c > (XEN) [<00000a0000281dcc>] domain_vgic_init+0x14c/0x210 > (XEN) [<00000a00002705a4>] arch_domain_create+0x150/0x1f0 > (XEN) [<00000a00002055e8>] domain_create+0x47c/0x6c0 > (XEN) [<00000a00002cf090>] create_domUs+0x7f8/0x8cc > (XEN) [<00000a00002eb588>] start_xen+0x8f4/0x998 > (XEN) [<00000a000020018c>] head.o#primary_switched+0x4/0x10 > (XEN) > (XEN) > (XEN) **************************************** > (XEN) Panic on CPU 0: > (XEN) Xen BUG at drivers/passthrough/arm/iommu_helpers.c:49 > (XEN) **************************************** > (XEN) > (XEN) Reboot in five seconds...
