1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/hv/mshv_common.c b/drivers/hv/mshv_common.c
new file mode 100644
index 000000000000..2575e6d7a71f
--- /dev/null
+++ b/drivers/hv/mshv_common.c
@@ -0,0 +1,161 @@
+// 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 "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);
+
+/*
+ * Handle any pre-processing before going into the guest mode on this cpu, most
+ * notably call schedule(). Must be invoked with both preemption and
+ * interrupts enabled.
+ *
+ * Returns: 0 on success, -errno on error.
+ */
+int mshv_do_pre_guest_mode_work(ulong th_flags)
+{
+	if (th_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
+		return -EINTR;
+
+	if (th_flags & _TIF_NEED_RESCHED)
+		schedule();
+
+	if (th_flags & _TIF_NOTIFY_RESUME)
+		resume_user_mode_work(NULL);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mshv_do_pre_guest_mode_work);