kvm: require KVM_CAP_SIGNAL_MSI

This was introduced in KVM in Linux 3.5, we can require it unconditionally
in kvm_irqchip_send_msi().  However, not all architectures have to implement
it so check it only in x86, the only architecture that ever had MSI injection
but not KVM_CAP_SIGNAL_MSI.

ARM uses it to detect the presence of the ITS emulation in the kernel,
introduced in Linux 4.8.  Assume that it's there and possibly fail when
realizing the arm-its-kvm device.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/hw/intc/arm_gicv3_its_common.c b/hw/intc/arm_gicv3_its_common.c
index abaf77057e..fddd6d490c 100644
--- a/hw/intc/arm_gicv3_its_common.c
+++ b/hw/intc/arm_gicv3_its_common.c
@@ -163,8 +163,7 @@ type_init(gicv3_its_common_register_types)
 const char *its_class_name(void)
 {
     if (kvm_irqchip_in_kernel()) {
-        /* KVM implementation requires this capability */
-        return kvm_direct_msi_enabled() ? "arm-its-kvm" : NULL;
+        return "arm-its-kvm";
     } else {
         /* Software emulation based model */
         return "arm-gicv3-its";