In build_rimt(), the calculation of `num_ids` for the ID mapping array incorrectly uses the same formula (`0xffff - s->pci_iommu_bdf`) for both System IOMMU and PCI IOMMU topologies.
For a System IOMMU, `s->pci_iommu_bdf` is 0. This results in a `num_ids` value of 0xffff. Since the source ID base starts at 0, the mapping only covers Requester IDs from 0 to 0xfffe. The final valid PCI Requester ID (0xffff) is erroneously omitted from the RIMT table. Fix this by decoupling the `num_ids` calculation. For System IOMMUs, explicitly set `num_ids` to 0x10000 to cover the entire PCI Requester ID space. This issue was discovered and reported by SpecHunter, an AI-driven architecture specification analysis tool. Link: https://github.com/yizishun/rv-isa-sec/blob/c78dacf66c8acd677b3538c837fde310bb71a97b/output/riscv-server-platform/pr-102/qemu.txt#L32 Signed-off-by: Zishun Yi <[email protected]> --- hw/riscv/virt-acpi-build.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/riscv/virt-acpi-build.c b/hw/riscv/virt-acpi-build.c index fd6ca5dbc4ff..413d47d70ef1 100644 --- a/hw/riscv/virt-acpi-build.c +++ b/hw/riscv/virt-acpi-build.c @@ -802,10 +802,11 @@ static void build_rimt(GArray *table_data, BIOSLinker *linker, range = &g_array_index(iommu_idmaps, AcpiRimtIdMapping, i); if (virt_is_iommu_sys_enabled(s)) { range->source_id_base = 0; + range->num_ids = 0x10000; } else { range->source_id_base = s->pci_iommu_bdf + 1; + range->num_ids = 0xffff - s->pci_iommu_bdf; } - range->num_ids = 0xffff - s->pci_iommu_bdf; build_rimt_id_mapping(table_data, range->source_id_base, range->num_ids, iommu_offset); } -- 2.51.2
