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 int hv_setup_vmbus_irq(int 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 extern int vmbus_interrupt;
 103
 104 #if IS_ENABLED(CONFIG_HYPERV)
 105 /*
 106  * Hypervisor's notion of virtual processor ID is different from
 107  * Linux' notion of CPU ID. This information can only be retrieved
 108  * in the context of the calling CPU. Setup a map for easy access
 109  * to this information.
 110  */
 111 extern u32 *hv_vp_index;
 112 extern u32 hv_max_vp_index;
 113
 114 /* Sentinel value for an uninitialized entry in hv_vp_index array */
 115 #define VP_INVAL        U32_MAX
 116
 117 /**
 118  * hv_cpu_number_to_vp_number() - Map CPU to VP.
 119  * @cpu_number: CPU number in Linux terms
 120  *
 121  * This function returns the mapping between the Linux processor
 122  * number and the hypervisor's virtual processor number, useful
 123  * in making hypercalls and such that talk about specific
 124  * processors.
 125  *
 126  * Return: Virtual processor number in Hyper-V terms
 127  */
 128 static inline int hv_cpu_number_to_vp_number(int cpu_number)
 129 {
 130         return hv_vp_index[cpu_number];
 131 }
 132
 133 static inline int cpumask_to_vpset(struct hv_vpset *vpset,
 134                                     const struct cpumask *cpus)
 135 {
 136         int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
 137
 138         /* valid_bank_mask can represent up to 64 banks */
 139         if (hv_max_vp_index / 64 >= 64)
 140                 return 0;
 141
 142         /*
 143          * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
 144          * structs are not cleared between calls, we risk flushing unneeded
 145          * vCPUs otherwise.
 146          */
 147         for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
 148                 vpset->bank_contents[vcpu_bank] = 0;
 149
 150         /*
 151          * Some banks may end up being empty but this is acceptable.
 152          */
 153         for_each_cpu(cpu, cpus) {
 154                 vcpu = hv_cpu_number_to_vp_number(cpu);
 155                 if (vcpu == VP_INVAL)
 156                         return -1;
 157                 vcpu_bank = vcpu / 64;
 158                 vcpu_offset = vcpu % 64;
 159                 __set_bit(vcpu_offset, (unsigned long *)
 160                           &vpset->bank_contents[vcpu_bank]);
 161                 if (vcpu_bank >= nr_bank)
 162                         nr_bank = vcpu_bank + 1;
 163         }
 164         vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
 165         return nr_bank;
 166 }
 167
 168 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
 169 void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
 170 bool hv_is_hyperv_initialized(void);
 171 bool hv_is_hibernation_supported(void);
 172 void hyperv_cleanup(void);
 173 #else /* CONFIG_HYPERV */
 174 static inline bool hv_is_hyperv_initialized(void) { return false; }
 175 static inline bool hv_is_hibernation_supported(void) { return false; }
 176 static inline void hyperv_cleanup(void) {}
 177 #endif /* CONFIG_HYPERV */
 178
 179 #if IS_ENABLED(CONFIG_HYPERV)
 180 extern int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void));
 181 extern void hv_remove_stimer0_irq(int irq);
 182 #endif
 183
 184 #endif