include/asm-generic/mshyperv.h

   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
  28 struct 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 };
  36 extern struct ms_hyperv_info ms_hyperv;
  37
  38 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
  39 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
  40
  41
  42 /* Generate the guest OS identifier as described in the Hyper-V TLFS */
  43 static 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 */
  58 static 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
  92 void hv_setup_vmbus_irq(void (*handler)(void));
  93 void hv_remove_vmbus_irq(void);
  94 void hv_enable_vmbus_irq(void);
  95 void hv_disable_vmbus_irq(void);
  96
  97 void hv_setup_kexec_handler(void (*handler)(void));
  98 void hv_remove_kexec_handler(void);
  99 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
 100 void 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  */
 109 extern u32 *hv_vp_index;
 110 extern 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  */
 126 static inline int hv_cpu_number_to_vp_number(int cpu_number)
 127 {
 128         return hv_vp_index[cpu_number];
 129 }
 130
 131 static 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
 166 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
 167 void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
 168 bool hv_is_hyperv_initialized(void);
 169 bool hv_is_hibernation_supported(void);
 170 void hyperv_cleanup(void);
 171 void hv_setup_sched_clock(void *sched_clock);
 172 #else /* CONFIG_HYPERV */
 173 static inline bool hv_is_hyperv_initialized(void) { return false; }
 174 static inline bool hv_is_hibernation_supported(void) { return false; }
 175 static inline void hyperv_cleanup(void) {}
 176 #endif /* CONFIG_HYPERV */
 177
 178 #if IS_ENABLED(CONFIG_HYPERV)
 179 extern int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void));
 180 extern void hv_remove_stimer0_irq(int irq);
 181 #endif
 182
 183 #endif