KVM: add basic paravirt support
Add basic KVM paravirt support. Avoid vm-exits on IO delays.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/include/asm-x86/kvm_para.h b/include/asm-x86/kvm_para.h
index 5ab7d3d..ed5df3a 100644
--- a/include/asm-x86/kvm_para.h
+++ b/include/asm-x86/kvm_para.h
@@ -10,7 +10,8 @@
* paravirtualization, the appropriate feature bit should be checked.
*/
#define KVM_CPUID_FEATURES 0x40000001
-#define KVM_FEATURE_CLOCKSOURCE 0
+#define KVM_FEATURE_CLOCKSOURCE 0
+#define KVM_FEATURE_NOP_IO_DELAY 1
#define MSR_KVM_WALL_CLOCK 0x11
#define MSR_KVM_SYSTEM_TIME 0x12
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index a2f3274..76f0947 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -237,6 +237,7 @@
#define KVM_CAP_NR_VCPUS 9 /* returns max vcpus per vm */
#define KVM_CAP_NR_MEMSLOTS 10 /* returns max memory slots per vm */
#define KVM_CAP_PIT 11
+#define KVM_CAP_NOP_IO_DELAY 12
/*
* ioctls for VM fds
