[PATCH] virt-host-validate: Detect SMMU support on ARMs
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(a)redhat.com>
---
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