handle fixed DM ICR writes in the kernel

Author: romank-msft

arch/x86/include/asm/svm.h

@@ -5,7 +5,8 @@
 #include <uapi/asm/svm.h>
 #include <uapi/asm/kvm.h>
 
-#include <asm/hyperv-tlfs.h>
+/* TODO: including into mshv_vtl_main.c breaks the build. */
+// #include <asm/hyperv-tlfs.h>
 
 /*
  * 32-bit intercept words in the VMCB Control Area, starting
@@ -164,7 +165,8 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 	 * for use by hypervisor/software.
 	 */
 	union {
-		struct hv_vmcb_enlightenments hv_enlightenments;
+		/* TODO: including into mshv_vtl_main.c breaks the build. */
+		// struct hv_vmcb_enlightenments hv_enlightenments;
 		u8 reserved_sw[32];
 	};
 };
@@ -195,6 +197,9 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 #define V_IGN_TPR_SHIFT 20
 #define V_IGN_TPR_MASK (1 << V_IGN_TPR_SHIFT)
 
+#define V_GUEST_BUSY_SHIFT 63
+#define V_GUEST_BUSY_MASK (1ULL << V_GUEST_BUSY_SHIFT)
+
 #define V_IRQ_INJECTION_BITS_MASK (V_IRQ_MASK | V_INTR_PRIO_MASK | V_IGN_TPR_MASK)
 
 #define V_INTR_MASKING_SHIFT 24