1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/hv/mshv_common.c b/drivers/hv/mshv_common.c
new file mode 100644
index 000000000000..58027b23c206
--- /dev/null
+++ b/drivers/hv/mshv_common.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024, Microsoft Corporation.
+ *
+ * This file contains functions that will be called from one or more modules.
+ * If any of these modules are configured to build, this file is built and just
+ * statically linked in.
+ *
+ * Authors: Microsoft Linux virtualization team
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <asm/mshyperv.h>
+#include <linux/resume_user_mode.h>
+#include <linux/export.h>
+#include <linux/acpi.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+
+#include "mshv.h"
+
+#define HV_GET_REGISTER_BATCH_SIZE	\
+	(HV_HYP_PAGE_SIZE / sizeof(union hv_register_value))
+#define HV_SET_REGISTER_BATCH_SIZE	\
+	((HV_HYP_PAGE_SIZE - sizeof(struct hv_input_set_vp_registers)) \
+		/ sizeof(struct hv_register_assoc))
+
+int hv_call_get_vp_registers(u32 vp_index, u64 partition_id, u16 count,
+			     union hv_input_vtl input_vtl,
+			     struct hv_register_assoc *registers)
+{
+	struct hv_input_get_vp_registers *input_page;
+	union hv_register_value *output_page;
+	u16 completed = 0;
+	unsigned long remaining = count;
+	int rep_count, i;
+	u64 status = HV_STATUS_SUCCESS;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
+	output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
+
+	input_page->partition_id = partition_id;
+	input_page->vp_index = vp_index;
+	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
+	input_page->rsvd_z8 = 0;
+	input_page->rsvd_z16 = 0;
+
+	while (remaining) {
+		rep_count = min(remaining, HV_GET_REGISTER_BATCH_SIZE);
+		for (i = 0; i < rep_count; ++i)
+			input_page->names[i] = registers[i].name;
+
+		status = hv_do_rep_hypercall(HVCALL_GET_VP_REGISTERS, rep_count,
+					     0, input_page, output_page);
+		if (!hv_result_success(status))
+			break;
+
+		completed = hv_repcomp(status);
+		for (i = 0; i < completed; ++i)
+			registers[i].value = output_page[i];
+
+		registers += completed;
+		remaining -= completed;
+	}
+	local_irq_restore(flags);
+
+	return hv_result_to_errno(status);
+}
+EXPORT_SYMBOL_GPL(hv_call_get_vp_registers);
+
+int hv_call_set_vp_registers(u32 vp_index, u64 partition_id, u16 count,
+			     union hv_input_vtl input_vtl,
+			     struct hv_register_assoc *registers)
+{
+	struct hv_input_set_vp_registers *input_page;
+	u16 completed = 0;
+	unsigned long remaining = count;
+	int rep_count;
+	u64 status = HV_STATUS_SUCCESS;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	input_page = *this_cpu_ptr(hyperv_pcpu_input_arg);
+
+	input_page->partition_id = partition_id;
+	input_page->vp_index = vp_index;
+	input_page->input_vtl.as_uint8 = input_vtl.as_uint8;
+	input_page->rsvd_z8 = 0;
+	input_page->rsvd_z16 = 0;
+
+	while (remaining) {
+		rep_count = min(remaining, HV_SET_REGISTER_BATCH_SIZE);
+		memcpy(input_page->elements, registers,
+		       sizeof(struct hv_register_assoc) * rep_count);
+
+		status = hv_do_rep_hypercall(HVCALL_SET_VP_REGISTERS, rep_count,
+					     0, input_page, NULL);
+		if (!hv_result_success(status))
+			break;
+
+		completed = hv_repcomp(status);
+		registers += completed;
+		remaining -= completed;
+	}
+
+	local_irq_restore(flags);
+
+	return hv_result_to_errno(status);
+}
+EXPORT_SYMBOL_GPL(hv_call_set_vp_registers);
+
+int hv_call_get_partition_property(u64 partition_id,
+				   u64 property_code,
+				   u64 *property_value)
+{
+	u64 status;
+	unsigned long flags;
+	struct hv_input_get_partition_property *input;
+	struct hv_output_get_partition_property *output;
+
+	local_irq_save(flags);
+	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
+	memset(input, 0, sizeof(*input));
+	input->partition_id = partition_id;
+	input->property_code = property_code;
+	status = hv_do_hypercall(HVCALL_GET_PARTITION_PROPERTY, input, output);
+
+	if (!hv_result_success(status)) {
+		local_irq_restore(flags);
+		return hv_result_to_errno(status);
+	}
+	*property_value = output->property_value;
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hv_call_get_partition_property);
+
+/*
+ * Corresponding sleep states have to be initialized in order for a subsequent
+ * HVCALL_ENTER_SLEEP_STATE call to succeed. Currently only S5 state as per
+ * ACPI 6.4 chapter 7.4.2 is relevant, while S1, S2 and S3 can be supported.
+ *
+ * In order to pass proper PM values to mshv, ACPI should be initialized and
+ * should support S5 sleep state when this method is invoked.
+ */
+static int hv_initialize_sleep_states(void)
+{
+	u64 status;
+	unsigned long flags;
+	struct hv_input_set_system_property *in;
+	acpi_status acpi_status;
+	u8 sleep_type_a, sleep_type_b;
+
+	if (!acpi_sleep_state_supported(ACPI_STATE_S5)) {
+		pr_err("%s: S5 sleep state not supported.\n", __func__);
+		return -ENODEV;
+	}
+
+	acpi_status = acpi_get_sleep_type_data(ACPI_STATE_S5, &sleep_type_a,
+					       &sleep_type_b);
+	if (ACPI_FAILURE(acpi_status))
+		return -ENODEV;
+
+	local_irq_save(flags);
+	in = *this_cpu_ptr(hyperv_pcpu_input_arg);
+	memset(in, 0, sizeof(*in));
+
+	in->property_id = HV_SYSTEM_PROPERTY_SLEEP_STATE;
+	in->set_sleep_state_info.sleep_state = HV_SLEEP_STATE_S5;
+	in->set_sleep_state_info.pm1a_slp_typ = sleep_type_a;
+	in->set_sleep_state_info.pm1b_slp_typ = sleep_type_b;
+
+	status = hv_do_hypercall(HVCALL_SET_SYSTEM_PROPERTY, in, NULL);
+	local_irq_restore(flags);
+
+	if (!hv_result_success(status)) {
+		hv_status_err(status, "\n");
+		return hv_result_to_errno(status);
+	}
+
+	return 0;
+}
+
+/*
+ * This notifier initializes sleep states in mshv hypervisor which will be
+ * used during power off.
+ */
+static int hv_reboot_notifier_handler(struct notifier_block *this,
+				      unsigned long code, void *another)
+{
+	int ret = 0;
+
+	if (code == SYS_HALT || code == SYS_POWER_OFF)
+		ret = hv_initialize_sleep_states();
+
+	return ret ? NOTIFY_DONE : NOTIFY_OK;
+}
+
+static struct notifier_block hv_reboot_notifier = {
+	.notifier_call = hv_reboot_notifier_handler,
+};
+
+void hv_sleep_notifiers_register(void)
+{
+	int ret;
+
+	ret = register_reboot_notifier(&hv_reboot_notifier);
+	if (ret)
+		pr_err("%s: cannot register reboot notifier %d\n", __func__,
+		       ret);
+}
+
+/*
+ * Power off the machine by entering S5 sleep state via Hyper-V hypercall.
+ * This call does not return if successful.
+ */
+void hv_machine_power_off(void)
+{
+	unsigned long flags;
+	struct hv_input_enter_sleep_state *in;
+
+	local_irq_save(flags);
+	in = *this_cpu_ptr(hyperv_pcpu_input_arg);
+	in->sleep_state = HV_SLEEP_STATE_S5;
+
+	(void)hv_do_hypercall(HVCALL_ENTER_SLEEP_STATE, in, NULL);
+	local_irq_restore(flags);
+
+	/* should never reach here */
+	BUG();
+
+}