KVM: Allow PIT emulation without speaker port

The in-kernel speaker emulation is only a dummy and also unneeded from
the performance point of view. Rather, it takes user space support to
generate sound output on the host, e.g. console beeps.

To allow this, introduce KVM_CREATE_PIT2 which controls in-kernel
speaker port emulation via a flag passed along the new IOCTL. It also
leaves room for future extensions of the PIT configuration interface.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 8f53f24e527..65df6f5e2b9 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -70,6 +70,14 @@ struct kvm_irqchip {
         } chip;
 };
 
+/* for KVM_CREATE_PIT2 */
+struct kvm_pit_config {
+        __u32 flags;
+        __u32 pad[15];
+};
+
+#define KVM_PIT_SPEAKER_DUMMY     1
+
 #define KVM_EXIT_UNKNOWN          0
 #define KVM_EXIT_EXCEPTION        1
 #define KVM_EXIT_IO               2
@@ -419,6 +427,9 @@ struct kvm_trace_rec {
 #define KVM_CAP_MCE 31
 #endif
 #define KVM_CAP_IRQFD 32
+#ifdef __KVM_HAVE_PIT
+#define KVM_CAP_PIT2 33
+#endif
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -525,6 +536,7 @@ struct kvm_irqfd {
                         _IOW(KVMIO, 0x74, struct kvm_assigned_msix_entry)
 #define KVM_DEASSIGN_DEV_IRQ       _IOW(KVMIO, 0x75, struct kvm_assigned_irq)
 #define KVM_IRQFD                  _IOW(KVMIO, 0x76, struct kvm_irqfd)
+#define KVM_CREATE_PIT2            _IOW(KVMIO, 0x77, struct kvm_pit_config)
 
 /*
  * ioctls for vcpu fds