linux/include/asm-generic/mshyperv.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2
   3/*
   4 * Linux-specific definitions for managing interactions with Microsoft's
   5 * Hyper-V hypervisor. The definitions in this file are architecture
   6 * independent. See arch/<arch>/include/asm/mshyperv.h for definitions
   7 * that are specific to architecture <arch>.
   8 *
   9 * Definitions that are specified in the Hyper-V Top Level Functional
  10 * Spec (TLFS) should not go in this file, but should instead go in
  11 * hyperv-tlfs.h.
  12 *
  13 * Copyright (C) 2019, Microsoft, Inc.
  14 *
  15 * Author : Michael Kelley <mikelley@microsoft.com>
  16 */
  17
  18#ifndef _ASM_GENERIC_MSHYPERV_H
  19#define _ASM_GENERIC_MSHYPERV_H
  20
  21#include <linux/types.h>
  22#include <linux/atomic.h>
  23#include <linux/bitops.h>
  24#include <linux/cpumask.h>
  25#include <asm/ptrace.h>
  26#include <asm/hyperv-tlfs.h>
  27
  28struct ms_hyperv_info {
  29        u32 features;
  30        u32 misc_features;
  31        u32 hints;
  32        u32 nested_features;
  33        u32 max_vp_index;
  34        u32 max_lp_index;
  35};
  36extern struct ms_hyperv_info ms_hyperv;
  37
  38extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
  39extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
  40
  41
  42/* Generate the guest OS identifier as described in the Hyper-V TLFS */
  43static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
  44                                       __u64 d_info2)
  45{
  46        __u64 guest_id = 0;
  47
  48        guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
  49        guest_id |= (d_info1 << 48);
  50        guest_id |= (kernel_version << 16);
  51        guest_id |= d_info2;
  52
  53        return guest_id;
  54}
  55
  56
  57/* Free the message slot and signal end-of-message if required */
  58static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
  59{
  60        /*
  61         * On crash we're reading some other CPU's message page and we need
  62         * to be careful: this other CPU may already had cleared the header
  63         * and the host may already had delivered some other message there.
  64         * In case we blindly write msg->header.message_type we're going
  65         * to lose it. We can still lose a message of the same type but
  66         * we count on the fact that there can only be one
  67         * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
  68         * on crash.
  69         */
  70        if (cmpxchg(&msg->header.message_type, old_msg_type,
  71                    HVMSG_NONE) != old_msg_type)
  72                return;
  73
  74        /*
  75         * The cmxchg() above does an implicit memory barrier to
  76         * ensure the write to MessageType (ie set to
  77         * HVMSG_NONE) happens before we read the
  78         * MessagePending and EOMing. Otherwise, the EOMing
  79         * will not deliver any more messages since there is
  80         * no empty slot
  81         */
  82        if (msg->header.message_flags.msg_pending) {
  83                /*
  84                 * This will cause message queue rescan to
  85                 * possibly deliver another msg from the
  86                 * hypervisor
  87                 */
  88                hv_signal_eom();
  89        }
  90}
  91
  92void hv_setup_vmbus_irq(void (*handler)(void));
  93void hv_remove_vmbus_irq(void);
  94void hv_enable_vmbus_irq(void);
  95void hv_disable_vmbus_irq(void);
  96
  97void hv_setup_kexec_handler(void (*handler)(void));
  98void hv_remove_kexec_handler(void);
  99void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
 100void hv_remove_crash_handler(void);
 101
 102#if IS_ENABLED(CONFIG_HYPERV)
 103/*
 104 * Hypervisor's notion of virtual processor ID is different from
 105 * Linux' notion of CPU ID. This information can only be retrieved
 106 * in the context of the calling CPU. Setup a map for easy access
 107 * to this information.
 108 */
 109extern u32 *hv_vp_index;
 110extern u32 hv_max_vp_index;
 111
 112/* Sentinel value for an uninitialized entry in hv_vp_index array */
 113#define VP_INVAL        U32_MAX
 114
 115/**
 116 * hv_cpu_number_to_vp_number() - Map CPU to VP.
 117 * @cpu_number: CPU number in Linux terms
 118 *
 119 * This function returns the mapping between the Linux processor
 120 * number and the hypervisor's virtual processor number, useful
 121 * in making hypercalls and such that talk about specific
 122 * processors.
 123 *
 124 * Return: Virtual processor number in Hyper-V terms
 125 */
 126static inline int hv_cpu_number_to_vp_number(int cpu_number)
 127{
 128        return hv_vp_index[cpu_number];
 129}
 130
 131static inline int cpumask_to_vpset(struct hv_vpset *vpset,
 132                                    const struct cpumask *cpus)
 133{
 134        int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
 135
 136        /* valid_bank_mask can represent up to 64 banks */
 137        if (hv_max_vp_index / 64 >= 64)
 138                return 0;
 139
 140        /*
 141         * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
 142         * structs are not cleared between calls, we risk flushing unneeded
 143         * vCPUs otherwise.
 144         */
 145        for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
 146                vpset->bank_contents[vcpu_bank] = 0;
 147
 148        /*
 149         * Some banks may end up being empty but this is acceptable.
 150         */
 151        for_each_cpu(cpu, cpus) {
 152                vcpu = hv_cpu_number_to_vp_number(cpu);
 153                if (vcpu == VP_INVAL)
 154                        return -1;
 155                vcpu_bank = vcpu / 64;
 156                vcpu_offset = vcpu % 64;
 157                __set_bit(vcpu_offset, (unsigned long *)
 158                          &vpset->bank_contents[vcpu_bank]);
 159                if (vcpu_bank >= nr_bank)
 160                        nr_bank = vcpu_bank + 1;
 161        }
 162        vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
 163        return nr_bank;
 164}
 165
 166void hyperv_report_panic(struct pt_regs *regs, long err);
 167void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
 168bool hv_is_hyperv_initialized(void);
 169void hyperv_cleanup(void);
 170void hv_setup_sched_clock(void *sched_clock);
 171#else /* CONFIG_HYPERV */
 172static inline bool hv_is_hyperv_initialized(void) { return false; }
 173static inline void hyperv_cleanup(void) {}
 174#endif /* CONFIG_HYPERV */
 175
 176#if IS_ENABLED(CONFIG_HYPERV)
 177extern int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void));
 178extern void hv_remove_stimer0_irq(int irq);
 179#endif
 180
 181#endif
 182