kvm: Add kvm_has_pit_state2 helper

To be used for in-kernel PIT emulation.

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

kvm-all.c

diff --git a/kvm-all.c b/kvm-all.c
index 77eadf6..278085f 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -76,6 +76,7 @@
     struct kvm_sw_breakpoint_head kvm_sw_breakpoints;
 #endif
     int pit_in_kernel;
+    int pit_state2;
     int xsave, xcrs;
     int many_ioeventfds;
     int irqchip_inject_ioctl;
@@ -1058,6 +1059,10 @@
     s->xcrs = kvm_check_extension(s, KVM_CAP_XCRS);
 #endif
 
+#ifdef KVM_CAP_PIT_STATE2
+    s->pit_state2 = kvm_check_extension(s, KVM_CAP_PIT_STATE2);
+#endif
+
     ret = kvm_arch_init(s);
     if (ret < 0) {
         goto err;
@@ -1390,6 +1395,11 @@
     return kvm_state->xcrs;
 }
 
+int kvm_has_pit_state2(void)
+{
+    return kvm_state->pit_state2;
+}
+
 int kvm_has_many_ioeventfds(void)
 {
     if (!kvm_enabled()) {

kvm-stub.c

diff --git a/kvm-stub.c b/kvm-stub.c
index f63a0d2..1f1c686 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -78,6 +78,11 @@
     return 1;
 }
 
+int kvm_has_pit_state2(void)
+{
+    return 0;
+}
+
 void kvm_setup_guest_memory(void *start, size_t size)
 {
 }

kvm.h

diff --git a/kvm.h b/kvm.h
index f9f1dc8..8ef4476 100644
--- a/kvm.h
+++ b/kvm.h
@@ -54,6 +54,7 @@
 int kvm_has_debugregs(void);
 int kvm_has_xsave(void);
 int kvm_has_xcrs(void);
+int kvm_has_pit_state2(void);
 int kvm_has_many_ioeventfds(void);
 int kvm_has_gsi_routing(void);