x86: KVM guest: 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>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/kvm_para.h b/include/linux/kvm_para.h
index 5497aac0d2f8..9c462c91a6b1 100644
--- a/include/linux/kvm_para.h
+++ b/include/linux/kvm_para.h
@@ -20,6 +20,12 @@
 #include <asm/kvm_para.h>
 
 #ifdef __KERNEL__
+#ifdef CONFIG_KVM_GUEST
+void __init kvm_guest_init(void);
+#else
+#define kvm_guest_init() do { } while (0)
+#endif
+
 static inline int kvm_para_has_feature(unsigned int feature)
 {
         if (kvm_arch_para_features() & (1UL << feature))