In vir-host-validate we do two checks related to IOMMU: 1) hardware support, and 2) kernel support. While users are usually interested in the latter, the former also makes sense. And for the former (hardware support) we have this huge if-else block for nearly every architecture, except ARM. Now, IOMMU is called SMMU in ARM world, and while there's certainly a definitive way of detecting SMMU support (e.g. via dumping some registers in asm), we can work around this - just like we do for Intel and AMD - and check for an ACPI table presence. In ARM world, there's I/O Remapping Table (IORT) which describes SMMU capabilities on given host and is exposed in sysfs (regardless of arm_smmu module). Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2178885 Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx> --- tools/virt-host-validate-common.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tools/virt-host-validate-common.c b/tools/virt-host-validate-common.c index a41bb346d2..49d3c4083b 100644 --- a/tools/virt-host-validate-common.c +++ b/tools/virt-host-validate-common.c @@ -388,6 +388,15 @@ int virHostValidateIOMMU(const char *hvname, return VIR_HOST_VALIDATE_FAILURE(VIR_HOST_VALIDATE_NOTE); } virHostMsgPass(); + } else if (ARCH_IS_ARM(arch)) { + if (access("/sys/firmware/acpi/tables/IORT", F_OK) == 0) { + virHostMsgPass(); + } else { + virHostMsgFail(level, + "No ACPI IORT table found, IOMMU not " + "supported by this hardware platform"); + return VIR_HOST_VALIDATE_FAILURE(level); + } } else { virHostMsgFail(level, "Unknown if this platform has IOMMU support"); -- 2.39.2
