mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![Jinank Jain](/assets/img/avatar_default.png)
Detect if Linux is running as a nested hypervisor in the root partition for Microsoft Hypervisor, using flags provided by MSHV. Expose a new variable hv_nested that is used later for decisions specific to the nested use case. Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/8e3e7112806e81d2292a66a56fe547162754ecea.1672639707.git.jinankjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
324 lines
8.3 KiB
C
324 lines
8.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
/*
|
|
* Architecture neutral utility routines for interacting with
|
|
* Hyper-V. This file is specifically for code that must be
|
|
* built-in to the kernel image when CONFIG_HYPERV is set
|
|
* (vs. being in a module) because it is called from architecture
|
|
* specific code under arch/.
|
|
*
|
|
* 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/bitfield.h>
|
|
#include <linux/cpumask.h>
|
|
#include <linux/panic_notifier.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/dma-map-ops.h>
|
|
#include <asm/hyperv-tlfs.h>
|
|
#include <asm/mshyperv.h>
|
|
|
|
/*
|
|
* hv_root_partition, ms_hyperv and hv_nested are defined here with other
|
|
* Hyper-V specific globals so they are shared across all architectures and are
|
|
* built only when CONFIG_HYPERV is defined. But on x86,
|
|
* ms_hyperv_init_platform() is built even when CONFIG_HYPERV is not
|
|
* defined, and it uses these three variables. So mark them as __weak
|
|
* here, allowing for an overriding definition in the module containing
|
|
* ms_hyperv_init_platform().
|
|
*/
|
|
bool __weak hv_root_partition;
|
|
EXPORT_SYMBOL_GPL(hv_root_partition);
|
|
|
|
bool __weak hv_nested;
|
|
EXPORT_SYMBOL_GPL(hv_nested);
|
|
|
|
struct ms_hyperv_info __weak ms_hyperv;
|
|
EXPORT_SYMBOL_GPL(ms_hyperv);
|
|
|
|
u32 *hv_vp_index;
|
|
EXPORT_SYMBOL_GPL(hv_vp_index);
|
|
|
|
u32 hv_max_vp_index;
|
|
EXPORT_SYMBOL_GPL(hv_max_vp_index);
|
|
|
|
void * __percpu *hyperv_pcpu_input_arg;
|
|
EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
|
|
|
|
void * __percpu *hyperv_pcpu_output_arg;
|
|
EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
|
|
|
|
/*
|
|
* Hyper-V specific initialization and shutdown code that is
|
|
* common across all architectures. Called from architecture
|
|
* specific initialization functions.
|
|
*/
|
|
|
|
void __init hv_common_free(void)
|
|
{
|
|
kfree(hv_vp_index);
|
|
hv_vp_index = NULL;
|
|
|
|
free_percpu(hyperv_pcpu_output_arg);
|
|
hyperv_pcpu_output_arg = NULL;
|
|
|
|
free_percpu(hyperv_pcpu_input_arg);
|
|
hyperv_pcpu_input_arg = NULL;
|
|
}
|
|
|
|
int __init hv_common_init(void)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* Hyper-V expects to get crash register data or kmsg when
|
|
* crash enlightment is available and system crashes. Set
|
|
* crash_kexec_post_notifiers to be true to make sure that
|
|
* calling crash enlightment interface before running kdump
|
|
* kernel.
|
|
*/
|
|
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
|
|
crash_kexec_post_notifiers = true;
|
|
pr_info("Hyper-V: enabling crash_kexec_post_notifiers\n");
|
|
}
|
|
|
|
/*
|
|
* Allocate the per-CPU state for the hypercall input arg.
|
|
* If this allocation fails, we will not be able to setup
|
|
* (per-CPU) hypercall input page and thus this failure is
|
|
* fatal on Hyper-V.
|
|
*/
|
|
hyperv_pcpu_input_arg = alloc_percpu(void *);
|
|
BUG_ON(!hyperv_pcpu_input_arg);
|
|
|
|
/* Allocate the per-CPU state for output arg for root */
|
|
if (hv_root_partition) {
|
|
hyperv_pcpu_output_arg = alloc_percpu(void *);
|
|
BUG_ON(!hyperv_pcpu_output_arg);
|
|
}
|
|
|
|
hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
|
|
GFP_KERNEL);
|
|
if (!hv_vp_index) {
|
|
hv_common_free();
|
|
return -ENOMEM;
|
|
}
|
|
|
|
for (i = 0; i < num_possible_cpus(); i++)
|
|
hv_vp_index[i] = VP_INVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Hyper-V specific initialization and die code for
|
|
* individual CPUs that is common across all architectures.
|
|
* Called by the CPU hotplug mechanism.
|
|
*/
|
|
|
|
int hv_common_cpu_init(unsigned int cpu)
|
|
{
|
|
void **inputarg, **outputarg;
|
|
u64 msr_vp_index;
|
|
gfp_t flags;
|
|
int pgcount = hv_root_partition ? 2 : 1;
|
|
|
|
/* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
|
|
flags = irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL;
|
|
|
|
inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
|
|
*inputarg = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags);
|
|
if (!(*inputarg))
|
|
return -ENOMEM;
|
|
|
|
if (hv_root_partition) {
|
|
outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
|
|
*outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
|
|
}
|
|
|
|
msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX);
|
|
|
|
hv_vp_index[cpu] = msr_vp_index;
|
|
|
|
if (msr_vp_index > hv_max_vp_index)
|
|
hv_max_vp_index = msr_vp_index;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int hv_common_cpu_die(unsigned int cpu)
|
|
{
|
|
unsigned long flags;
|
|
void **inputarg, **outputarg;
|
|
void *mem;
|
|
|
|
local_irq_save(flags);
|
|
|
|
inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
|
|
mem = *inputarg;
|
|
*inputarg = NULL;
|
|
|
|
if (hv_root_partition) {
|
|
outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
|
|
*outputarg = NULL;
|
|
}
|
|
|
|
local_irq_restore(flags);
|
|
|
|
kfree(mem);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Bit mask of the extended capability to query: see HV_EXT_CAPABILITY_xxx */
|
|
bool hv_query_ext_cap(u64 cap_query)
|
|
{
|
|
/*
|
|
* The address of the 'hv_extended_cap' variable will be used as an
|
|
* output parameter to the hypercall below and so it should be
|
|
* compatible with 'virt_to_phys'. Which means, it's address should be
|
|
* directly mapped. Use 'static' to keep it compatible; stack variables
|
|
* can be virtually mapped, making them incompatible with
|
|
* 'virt_to_phys'.
|
|
* Hypercall input/output addresses should also be 8-byte aligned.
|
|
*/
|
|
static u64 hv_extended_cap __aligned(8);
|
|
static bool hv_extended_cap_queried;
|
|
u64 status;
|
|
|
|
/*
|
|
* Querying extended capabilities is an extended hypercall. Check if the
|
|
* partition supports extended hypercall, first.
|
|
*/
|
|
if (!(ms_hyperv.priv_high & HV_ENABLE_EXTENDED_HYPERCALLS))
|
|
return false;
|
|
|
|
/* Extended capabilities do not change at runtime. */
|
|
if (hv_extended_cap_queried)
|
|
return hv_extended_cap & cap_query;
|
|
|
|
status = hv_do_hypercall(HV_EXT_CALL_QUERY_CAPABILITIES, NULL,
|
|
&hv_extended_cap);
|
|
|
|
/*
|
|
* The query extended capabilities hypercall should not fail under
|
|
* any normal circumstances. Avoid repeatedly making the hypercall, on
|
|
* error.
|
|
*/
|
|
hv_extended_cap_queried = true;
|
|
if (!hv_result_success(status)) {
|
|
pr_err("Hyper-V: Extended query capabilities hypercall failed 0x%llx\n",
|
|
status);
|
|
return false;
|
|
}
|
|
|
|
return hv_extended_cap & cap_query;
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_query_ext_cap);
|
|
|
|
void hv_setup_dma_ops(struct device *dev, bool coherent)
|
|
{
|
|
/*
|
|
* Hyper-V does not offer a vIOMMU in the guest
|
|
* VM, so pass 0/NULL for the IOMMU settings
|
|
*/
|
|
arch_setup_dma_ops(dev, 0, 0, NULL, coherent);
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_setup_dma_ops);
|
|
|
|
bool hv_is_hibernation_supported(void)
|
|
{
|
|
return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4);
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
|
|
|
|
/*
|
|
* Default function to read the Hyper-V reference counter, independent
|
|
* of whether Hyper-V enlightened clocks/timers are being used. But on
|
|
* architectures where it is used, Hyper-V enlightenment code in
|
|
* hyperv_timer.c may override this function.
|
|
*/
|
|
static u64 __hv_read_ref_counter(void)
|
|
{
|
|
return hv_get_register(HV_REGISTER_TIME_REF_COUNT);
|
|
}
|
|
|
|
u64 (*hv_read_reference_counter)(void) = __hv_read_ref_counter;
|
|
EXPORT_SYMBOL_GPL(hv_read_reference_counter);
|
|
|
|
/* These __weak functions provide default "no-op" behavior and
|
|
* may be overridden by architecture specific versions. Architectures
|
|
* for which the default "no-op" behavior is sufficient can leave
|
|
* them unimplemented and not be cluttered with a bunch of stub
|
|
* functions in arch-specific code.
|
|
*/
|
|
|
|
bool __weak hv_is_isolation_supported(void)
|
|
{
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_is_isolation_supported);
|
|
|
|
bool __weak hv_isolation_type_snp(void)
|
|
{
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
|
|
|
|
void __weak hv_setup_vmbus_handler(void (*handler)(void))
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_setup_vmbus_handler);
|
|
|
|
void __weak hv_remove_vmbus_handler(void)
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler);
|
|
|
|
void __weak hv_setup_kexec_handler(void (*handler)(void))
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_setup_kexec_handler);
|
|
|
|
void __weak hv_remove_kexec_handler(void)
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_remove_kexec_handler);
|
|
|
|
void __weak hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_setup_crash_handler);
|
|
|
|
void __weak hv_remove_crash_handler(void)
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_remove_crash_handler);
|
|
|
|
void __weak hyperv_cleanup(void)
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(hyperv_cleanup);
|
|
|
|
u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
|
|
{
|
|
return HV_STATUS_INVALID_PARAMETER;
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);
|
|
|
|
void __weak *hv_map_memory(void *addr, unsigned long size)
|
|
{
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_map_memory);
|
|
|
|
void __weak hv_unmap_memory(void *addr)
|
|
{
|
|
}
|
|
EXPORT_SYMBOL_GPL(hv_unmap_memory);
|