@@ -33,6 +33,9 @@
 #define HYPERV_CPUID_ENLIGHTMENT_INFO		0x40000004
 #define HYPERV_CPUID_IMPLEMENT_LIMITS		0x40000005
 #define HYPERV_CPUID_NESTED_FEATURES		0x4000000A
+#define HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS	0x40000080
+#define HYPERV_CPUID_SYNDBG_INTERFACE			0x40000081
+#define HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES	0x40000082
 
 #define HYPERV_HYPERVISOR_PRESENT_BIT		0x80000000
 #define HYPERV_CPUID_MIN			0x40000005

@@ -131,6 +134,8 @@
 #define HV_FEATURE_FREQUENCY_MSRS_AVAILABLE		BIT(8)
 /* Crash MSR available */
 #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE		BIT(10)
+/* Support for debug MSRs available */
+#define HV_FEATURE_DEBUG_MSRS_AVAILABLE			BIT(11)
 /* stimer Direct Mode is available */
 #define HV_STIMER_DIRECT_MODE_AVAILABLE			BIT(19)
 

@@ -194,6 +199,12 @@
 #define HV_X64_NESTED_GUEST_MAPPING_FLUSH		BIT(18)
 #define HV_X64_NESTED_MSR_BITMAP			BIT(19)
 
+/*
+ * Hyper-V synthetic debugger platform capabilities
+ * These are HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES.EAX bits.
+ */
+#define HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING	BIT(1)
+
 /* Hyper-V specific model specific registers (MSRs) */
 
 /* MSR used to identify the guest OS. */

@@ -267,6 +278,17 @@
 /* Hyper-V guest idle MSR */
 #define HV_X64_MSR_GUEST_IDLE			0x400000F0
 
+/* Hyper-V Synthetic debug options MSR */
+#define HV_X64_MSR_SYNDBG_CONTROL		0x400000F1
+#define HV_X64_MSR_SYNDBG_STATUS		0x400000F2
+#define HV_X64_MSR_SYNDBG_SEND_BUFFER		0x400000F3
+#define HV_X64_MSR_SYNDBG_RECV_BUFFER		0x400000F4
+#define HV_X64_MSR_SYNDBG_PENDING_BUFFER	0x400000F5
+#define HV_X64_MSR_SYNDBG_OPTIONS		0x400000FF
+
+/* Hyper-V HV_X64_MSR_SYNDBG_OPTIONS bits */
+#define HV_X64_SYNDBG_OPTION_USE_HCALLS		BIT(2)
+
 /* Hyper-V guest crash notification MSR's */
 #define HV_X64_MSR_CRASH_P0			0x40000100
 #define HV_X64_MSR_CRASH_P1			0x40000101

@@ -376,6 +398,9 @@ struct hv_tsc_emulation_status {
 #define HVCALL_SEND_IPI_EX			0x0015
 #define HVCALL_POST_MESSAGE			0x005c
 #define HVCALL_SIGNAL_EVENT			0x005d
+#define HVCALL_POST_DEBUG_DATA			0x0069
+#define HVCALL_RETRIEVE_DEBUG_DATA		0x006a
+#define HVCALL_RESET_DEBUG_SESSION		0x006b
 #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
 #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
 

@@ -419,6 +444,7 @@ enum HV_GENERIC_SET_FORMAT {
 #define HV_STATUS_INVALID_HYPERCALL_INPUT	3
 #define HV_STATUS_INVALID_ALIGNMENT		4
 #define HV_STATUS_INVALID_PARAMETER		5
+#define HV_STATUS_OPERATION_DENIED		8
 #define HV_STATUS_INSUFFICIENT_MEMORY		11
 #define HV_STATUS_INVALID_PORT_ID		17
 #define HV_STATUS_INVALID_CONNECTION_ID		18