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); 167 void hyperv_report_panic_msg(phys_addr_t pa, size_t size); 168 bool hv_is_hyperv_initialized(void); 169 void hyperv_cleanup(void); 170 void hv_setup_sched_clock(void *sched_clock); 171 #else /* CONFIG_HYPERV */ 172 static inline bool hv_is_hyperv_initialized(void) { return false; } 173 static inline void hyperv_cleanup(void) {} 174 #endif /* CONFIG_HYPERV */ 175 176 #if IS_ENABLED(CONFIG_HYPERV) 177 extern int hv_setup_stimer0_irq(int *irq, int *vector, void (*handler)(void)); 178 extern void hv_remove_stimer0_irq(int irq); 179 #endif 180 181 #endif 182