[PATCH v3 5/5] KVM: selftests: List the IOMMU modes in irq_test's help output

[David Matlack <dmatlack@google.com>]

List the names of all known IOMMU modes, and of the IOMMU modes that are
available on the current system, in the help output for irq_test's -t
option.

The help output currently lists only vfio_type1_iommu and iommufd, even
though the VFIO selftests library supports five IOMMU modes, and the
list would go stale whenever a mode is added. List the available modes
separately so that users can see which modes work on the current system.

Opportunistically refer to the -t option's argument as iommu_mode rather
than iommu_type in the usage line, to match the help text.

Signed-off-by: David Matlack <dmatlack@google.com>
---
 tools/testing/selftests/kvm/irq_test.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/irq_test.c b/tools/testing/selftests/kvm/irq_test.c
index 0d6ca1a052c4..9076271cc0dd 100644
--- a/tools/testing/selftests/kvm/irq_test.c
+++ b/tools/testing/selftests/kvm/irq_test.c
@@ -150,7 +150,7 @@ static void kvm_set_empty_gsi_routing(struct kvm_vm *vm)
 
 static void help(const char *name)
 {
-	printf("Usage: %s [-a] [-d <segment:bus:device.function>] [-e] [-h] [-i nr_irqs] [-m] [-n] [-t iommu_type] [-v nr_vcpus] [-x]\n", name);
+	printf("Usage: %s [-a] [-d <segment:bus:device.function>] [-e] [-h] [-i nr_irqs] [-m] [-n] [-t iommu_mode] [-v nr_vcpus] [-x]\n", name);
 	printf("\n");
 	printf("Tests KVM interrupt routing and delivery via irqfd.\n");
 	printf("-a	Affine the device's host IRQ to a random physical CPU\n");
@@ -159,7 +159,9 @@ static void help(const char *name)
 	printf("-i	The number of IRQs to generate during the test\n");
 	printf("-m	Pin target vCPU to random physical CPU before triggering interrupt\n");
 	printf("-n	Deliver 50 percent of IRQs as non-maskable interrupts\n");
-	printf("-t	Override the IOMMU type to use (vfio_type1_iommu or iommufd)\n");
+	printf("-t	Override the IOMMU mode to use\n");
+	printf("	Options: %s\n", iommu_mode_names_all());
+	printf("	Available: %s\n", iommu_mode_names_available());
 	printf("-v	Number of vCPUS to run\n");
 	printf("-x	Use xAPIC mode instead of x2APIC mode in the guest\n");
 	printf("\n");
-- 
2.56.0.506.g506a7eabc5-goog