1 files changed, 66 insertions, 17 deletions

diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
index f1b8a04ee9f2..4fdc26ade1d7 100644
--- a/arch/arm64/hyperv/mshyperv.c
+++ b/arch/arm64/hyperv/mshyperv.c
@@ -19,49 +19,90 @@
 
 static bool hyperv_initialized;
 
+int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
+{
+	hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION,
+			 (struct hv_get_vp_registers_output *)info);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hv_get_hypervisor_version);
+
+#ifdef CONFIG_ACPI
+
+static bool __init hyperv_detect_via_acpi(void)
+{
+	if (acpi_disabled)
+		return false;
+	/*
+	 * Hypervisor ID is only available in ACPI v6+, and the
+	 * structure layout was extended in v6 to accommodate that
+	 * new field.
+	 *
+	 * At the very minimum, this check makes sure not to read
+	 * past the FADT structure.
+	 *
+	 * It is also needed to catch running in some unknown
+	 * non-Hyper-V environment that has ACPI 5.x or less.
+	 * In such a case, it can't be Hyper-V.
+	 */
+	if (acpi_gbl_FADT.header.revision < 6)
+		return false;
+	return strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8) == 0;
+}
+
+#else
+
+static bool __init hyperv_detect_via_acpi(void)
+{
+	return false;
+}
+
+#endif
+
+static bool __init hyperv_detect_via_smccc(void)
+{
+	uuid_t hyperv_uuid = UUID_INIT(
+		0x58ba324d, 0x6447, 0x24cd,
+		0x75, 0x6c, 0xef, 0x8e,
+		0x24, 0x70, 0x59, 0x16);
+
+	return arm_smccc_hypervisor_has_uuid(&hyperv_uuid);
+}
+
 static int __init hyperv_init(void)
 {
 	struct hv_get_vp_registers_output	result;
-	u32	a, b, c, d;
 	u64	guest_id;
 	int	ret;
 
 	/*
 	 * Allow for a kernel built with CONFIG_HYPERV to be running in
-	 * a non-Hyper-V environment, including on DT instead of ACPI.
+	 * a non-Hyper-V environment.
+	 *
 	 * In such cases, do nothing and return success.
 	 */
-	if (acpi_disabled)
-		return 0;
-
-	if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8))
+	if (!hyperv_detect_via_acpi() && !hyperv_detect_via_smccc())
 		return 0;
 
 	/* Setup the guest ID */
 	guest_id = hv_generate_guest_id(LINUX_VERSION_CODE);
-	hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id);
+	hv_set_vpreg(HV_REGISTER_GUEST_OS_ID, guest_id);
 
 	/* Get the features and hints from Hyper-V */
-	hv_get_vpreg_128(HV_REGISTER_FEATURES, &result);
+	hv_get_vpreg_128(HV_REGISTER_PRIVILEGES_AND_FEATURES_INFO, &result);
 	ms_hyperv.features = result.as32.a;
 	ms_hyperv.priv_high = result.as32.b;
 	ms_hyperv.misc_features = result.as32.c;
 
-	hv_get_vpreg_128(HV_REGISTER_ENLIGHTENMENTS, &result);
+	hv_get_vpreg_128(HV_REGISTER_FEATURES_INFO, &result);
 	ms_hyperv.hints = result.as32.a;
 
 	pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n",
 		ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints,
 		ms_hyperv.misc_features);
 
-	/* Get information about the Hyper-V host version */
-	hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, &result);
-	a = result.as32.a;
-	b = result.as32.b;
-	c = result.as32.c;
-	d = result.as32.d;
-	pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n",
-		b >> 16, b & 0xFFFF, a,	d & 0xFFFFFF, c, d >> 24);
+	hv_identify_partition_type();
 
 	ret = hv_common_init();
 	if (ret)
@@ -74,6 +115,14 @@ static int __init hyperv_init(void)
 		return ret;
 	}
 
+	if (ms_hyperv.priv_high & HV_ACCESS_PARTITION_ID)
+		hv_get_partition_id();
+	ms_hyperv.vtl = get_vtl();
+	if (ms_hyperv.vtl > 0) /* non default VTL */
+		pr_info("Linux runs in Hyper-V Virtual Trust Level %d\n", ms_hyperv.vtl);
+
+	ms_hyperv_late_init();
+
 	hyperv_initialized = true;
 	return 0;
 }