mirror_ubuntu-kernels/arch/arm64/hyperv/mshyperv.c

88 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Core routines for interacting with Microsoft's Hyper-V hypervisor,
* including hypervisor initialization.
*
* Copyright (C) 2021, Microsoft, Inc.
*
* Author : Michael Kelley <mikelley@microsoft.com>
*/
#include <linux/types.h>
#include <linux/acpi.h>
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/version.h>
#include <linux/cpuhotplug.h>
#include <asm/mshyperv.h>
static bool hyperv_initialized;
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.
* In such cases, do nothing and return success.
*/
if (acpi_disabled)
return 0;
if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8))
return 0;
/* Setup the guest ID */
guest_id = hv_generate_guest_id(LINUX_VERSION_CODE);
hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id);
/* Get the features and hints from Hyper-V */
hv_get_vpreg_128(HV_REGISTER_FEATURES, &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);
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);
ret = hv_common_init();
if (ret)
return ret;
ret = cpuhp_setup_state(CPUHP_AP_HYPERV_ONLINE, "arm64/hyperv_init:online",
hv_common_cpu_init, hv_common_cpu_die);
if (ret < 0) {
hv_common_free();
return ret;
}
hyperv_initialized = true;
return 0;
}
early_initcall(hyperv_init);
bool hv_is_hyperv_initialized(void)
{
return hyperv_initialized;
}
EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);