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 priv_high; 31 u32 misc_features; 32 u32 hints; 33 u32 nested_features; 34 u32 max_vp_index; 35 u32 max_lp_index; 36 u32 isolation_config_a; 37 u32 isolation_config_b; 38 }; 39 extern struct ms_hyperv_info ms_hyperv; 40 41 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr); 42 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8); 43 44 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */ 45 static inline int hv_result(u64 status) 46 { 47 return status & HV_HYPERCALL_RESULT_MASK; 48 } 49 50 static inline bool hv_result_success(u64 status) 51 { 52 return hv_result(status) == HV_STATUS_SUCCESS; 53 } 54 55 static inline unsigned int hv_repcomp(u64 status) 56 { 57 /* Bits [43:32] of status have 'Reps completed' data. */ 58 return (status & HV_HYPERCALL_REP_COMP_MASK) >> 59 HV_HYPERCALL_REP_COMP_OFFSET; 60 } 61 62 /* 63 * Rep hypercalls. Callers of this functions are supposed to ensure that 64 * rep_count and varhead_size comply with Hyper-V hypercall definition. 65 */ 66 static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size, 67 void *input, void *output) 68 { 69 u64 control = code; 70 u64 status; 71 u16 rep_comp; 72 73 control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET; 74 control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET; 75 76 do { 77 status = hv_do_hypercall(control, input, output); 78 if (!hv_result_success(status)) 79 return status; 80 81 rep_comp = hv_repcomp(status); 82 83 control &= ~HV_HYPERCALL_REP_START_MASK; 84 control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET; 85 86 touch_nmi_watchdog(); 87 } while (rep_comp < rep_count); 88 89 return status; 90 } 91 92 /* Generate the guest OS identifier as described in the Hyper-V TLFS */ 93 static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version, 94 __u64 d_info2) 95 { 96 __u64 guest_id = 0; 97 98 guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48); 99 guest_id |= (d_info1 << 48); 100 guest_id |= (kernel_version << 16); 101 guest_id |= d_info2; 102 103 return guest_id; 104 } 105 106 /* Free the message slot and signal end-of-message if required */ 107 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type) 108 { 109 /* 110 * On crash we're reading some other CPU's message page and we need 111 * to be careful: this other CPU may already had cleared the header 112 * and the host may already had delivered some other message there. 113 * In case we blindly write msg->header.message_type we're going 114 * to lose it. We can still lose a message of the same type but 115 * we count on the fact that there can only be one 116 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages 117 * on crash. 118 */ 119 if (cmpxchg(&msg->header.message_type, old_msg_type, 120 HVMSG_NONE) != old_msg_type) 121 return; 122 123 /* 124 * The cmxchg() above does an implicit memory barrier to 125 * ensure the write to MessageType (ie set to 126 * HVMSG_NONE) happens before we read the 127 * MessagePending and EOMing. Otherwise, the EOMing 128 * will not deliver any more messages since there is 129 * no empty slot 130 */ 131 if (msg->header.message_flags.msg_pending) { 132 /* 133 * This will cause message queue rescan to 134 * possibly deliver another msg from the 135 * hypervisor 136 */ 137 hv_set_register(HV_REGISTER_EOM, 0); 138 } 139 } 140 141 void hv_setup_vmbus_handler(void (*handler)(void)); 142 void hv_remove_vmbus_handler(void); 143 void hv_setup_stimer0_handler(void (*handler)(void)); 144 void hv_remove_stimer0_handler(void); 145 146 void hv_setup_kexec_handler(void (*handler)(void)); 147 void hv_remove_kexec_handler(void); 148 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); 149 void hv_remove_crash_handler(void); 150 151 extern int vmbus_interrupt; 152 extern int vmbus_irq; 153 154 #if IS_ENABLED(CONFIG_HYPERV) 155 /* 156 * Hypervisor's notion of virtual processor ID is different from 157 * Linux' notion of CPU ID. This information can only be retrieved 158 * in the context of the calling CPU. Setup a map for easy access 159 * to this information. 160 */ 161 extern u32 *hv_vp_index; 162 extern u32 hv_max_vp_index; 163 164 /* Sentinel value for an uninitialized entry in hv_vp_index array */ 165 #define VP_INVAL U32_MAX 166 167 void *hv_alloc_hyperv_page(void); 168 void *hv_alloc_hyperv_zeroed_page(void); 169 void hv_free_hyperv_page(unsigned long addr); 170 171 /** 172 * hv_cpu_number_to_vp_number() - Map CPU to VP. 173 * @cpu_number: CPU number in Linux terms 174 * 175 * This function returns the mapping between the Linux processor 176 * number and the hypervisor's virtual processor number, useful 177 * in making hypercalls and such that talk about specific 178 * processors. 179 * 180 * Return: Virtual processor number in Hyper-V terms 181 */ 182 static inline int hv_cpu_number_to_vp_number(int cpu_number) 183 { 184 return hv_vp_index[cpu_number]; 185 } 186 187 static inline int cpumask_to_vpset(struct hv_vpset *vpset, 188 const struct cpumask *cpus) 189 { 190 int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1; 191 192 /* valid_bank_mask can represent up to 64 banks */ 193 if (hv_max_vp_index / 64 >= 64) 194 return 0; 195 196 /* 197 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex 198 * structs are not cleared between calls, we risk flushing unneeded 199 * vCPUs otherwise. 200 */ 201 for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++) 202 vpset->bank_contents[vcpu_bank] = 0; 203 204 /* 205 * Some banks may end up being empty but this is acceptable. 206 */ 207 for_each_cpu(cpu, cpus) { 208 vcpu = hv_cpu_number_to_vp_number(cpu); 209 if (vcpu == VP_INVAL) 210 return -1; 211 vcpu_bank = vcpu / 64; 212 vcpu_offset = vcpu % 64; 213 __set_bit(vcpu_offset, (unsigned long *) 214 &vpset->bank_contents[vcpu_bank]); 215 if (vcpu_bank >= nr_bank) 216 nr_bank = vcpu_bank + 1; 217 } 218 vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0); 219 return nr_bank; 220 } 221 222 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die); 223 bool hv_is_hyperv_initialized(void); 224 bool hv_is_hibernation_supported(void); 225 enum hv_isolation_type hv_get_isolation_type(void); 226 bool hv_is_isolation_supported(void); 227 void hyperv_cleanup(void); 228 bool hv_query_ext_cap(u64 cap_query); 229 #else /* CONFIG_HYPERV */ 230 static inline bool hv_is_hyperv_initialized(void) { return false; } 231 static inline bool hv_is_hibernation_supported(void) { return false; } 232 static inline void hyperv_cleanup(void) {} 233 #endif /* CONFIG_HYPERV */ 234 235 #endif 236