The IORT doc defines "Number of IDs" ("id_count" in the virt-acpi-build)
to be "the number of IDs in the range minus one". Otherwise, Linux kernel
reports "conflicting mapping for input ID" FW_BUG at the overlapped ID.
Fixes: 42e0f050e3a5 ("hw/arm/virt-acpi-build: Add IORT support to bypass
SMMUv3")
Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
---
Changelog
v2:
* Moved "-1" to the same line of id_count calculation
* Added "+1" to the next_range.input_base calculation
v1:
https://lore.kernel.org/all/20240613234802.828265-1-nicol...@nvidia.com/
hw/arm/virt-acpi-build.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index c3ccfef026..631f2c6d04 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -243,7 +243,8 @@ iort_host_bridges(Object *obj, void *opaque)
AcpiIortIdMapping idmap = {
.input_base = min_bus << 8,
- .id_count = (max_bus - min_bus + 1) << 8,
+ /* id_count is the number of IDs in the range minus one */
+ .id_count = ((max_bus - min_bus + 1) << 8) - 1,
};
g_array_append_val(idmap_blob, idmap);
}
@@ -298,11 +299,13 @@ build_iort(GArray *table_data, BIOSLinker *linker,
VirtMachineState *vms)
idmap = &g_array_index(smmu_idmaps, AcpiIortIdMapping, i);
if (next_range.input_base < idmap->input_base) {
- next_range.id_count = idmap->input_base -
next_range.input_base;
+ /* id_count is the number of IDs in the range minus one */
+ next_range.id_count = idmap->input_base -
+ next_range.input_base - 1;
g_array_append_val(its_idmaps, next_range);
}
- next_range.input_base = idmap->input_base + idmap->id_count;
+ next_range.input_base = idmap->input_base + idmap->id_count + 1;
}
/* Append the last RC -> ITS ID mapping */
--
2.43.0
