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 features_b; 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 45 /* Generate the guest OS identifier as described in the Hyper-V TLFS */ 46 static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version, 47 __u64 d_info2) 48 { 49 __u64 guest_id = 0; 50 51 guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48); 52 guest_id |= (d_info1 << 48); 53 guest_id |= (kernel_version << 16); 54 guest_id |= d_info2; 55 56 return guest_id; 57 } 58 59 60 /* Free the message slot and signal end-of-message if required */ 61 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type) 62 { 63 /* 64 * On crash we're reading some other CPU's message page and we need 65 * to be careful: this other CPU may already had cleared the header 66 * and the host may already had delivered some other message there. 67 * In case we blindly write msg->header.message_type we're going 68 * to lose it. We can still lose a message of the same type but 69 * we count on the fact that there can only be one 70 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages 71 * on crash. 72 */ 73 if (cmpxchg(&msg->header.message_type, old_msg_type, 74 HVMSG_NONE) != old_msg_type) 75 return; 76 77 /* 78 * The cmxchg() above does an implicit memory barrier to 79 * ensure the write to MessageType (ie set to 80 * HVMSG_NONE) happens before we read the 81 * MessagePending and EOMing. Otherwise, the EOMing 82 * will not deliver any more messages since there is 83 * no empty slot 84 */ 85 if (msg->header.message_flags.msg_pending) { 86 /* 87 * This will cause message queue rescan to 88 * possibly deliver another msg from the 89 * hypervisor 90 */ 91 hv_set_register(HV_REGISTER_EOM, 0); 92 } 93 } 94 95 void hv_setup_vmbus_handler(void (*handler)(void)); 96 void hv_remove_vmbus_handler(void); 97 void hv_setup_stimer0_handler(void (*handler)(void)); 98 void hv_remove_stimer0_handler(void); 99 100 void hv_setup_kexec_handler(void (*handler)(void)); 101 void hv_remove_kexec_handler(void); 102 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); 103 void hv_remove_crash_handler(void); 104 105 extern int vmbus_interrupt; 106 extern int vmbus_irq; 107 108 #if IS_ENABLED(CONFIG_HYPERV) 109 /* 110 * Hypervisor's notion of virtual processor ID is different from 111 * Linux' notion of CPU ID. This information can only be retrieved 112 * in the context of the calling CPU. Setup a map for easy access 113 * to this information. 114 */ 115 extern u32 *hv_vp_index; 116 extern u32 hv_max_vp_index; 117 118 /* Sentinel value for an uninitialized entry in hv_vp_index array */ 119 #define VP_INVAL U32_MAX 120 121 void *hv_alloc_hyperv_page(void); 122 void *hv_alloc_hyperv_zeroed_page(void); 123 void hv_free_hyperv_page(unsigned long addr); 124 125 /** 126 * hv_cpu_number_to_vp_number() - Map CPU to VP. 127 * @cpu_number: CPU number in Linux terms 128 * 129 * This function returns the mapping between the Linux processor 130 * number and the hypervisor's virtual processor number, useful 131 * in making hypercalls and such that talk about specific 132 * processors. 133 * 134 * Return: Virtual processor number in Hyper-V terms 135 */ 136 static inline int hv_cpu_number_to_vp_number(int cpu_number) 137 { 138 return hv_vp_index[cpu_number]; 139 } 140 141 static inline int cpumask_to_vpset(struct hv_vpset *vpset, 142 const struct cpumask *cpus) 143 { 144 int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1; 145 146 /* valid_bank_mask can represent up to 64 banks */ 147 if (hv_max_vp_index / 64 >= 64) 148 return 0; 149 150 /* 151 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex 152 * structs are not cleared between calls, we risk flushing unneeded 153 * vCPUs otherwise. 154 */ 155 for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++) 156 vpset->bank_contents[vcpu_bank] = 0; 157 158 /* 159 * Some banks may end up being empty but this is acceptable. 160 */ 161 for_each_cpu(cpu, cpus) { 162 vcpu = hv_cpu_number_to_vp_number(cpu); 163 if (vcpu == VP_INVAL) 164 return -1; 165 vcpu_bank = vcpu / 64; 166 vcpu_offset = vcpu % 64; 167 __set_bit(vcpu_offset, (unsigned long *) 168 &vpset->bank_contents[vcpu_bank]); 169 if (vcpu_bank >= nr_bank) 170 nr_bank = vcpu_bank + 1; 171 } 172 vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0); 173 return nr_bank; 174 } 175 176 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die); 177 bool hv_is_hyperv_initialized(void); 178 bool hv_is_hibernation_supported(void); 179 enum hv_isolation_type hv_get_isolation_type(void); 180 bool hv_is_isolation_supported(void); 181 void hyperv_cleanup(void); 182 #else /* CONFIG_HYPERV */ 183 static inline bool hv_is_hyperv_initialized(void) { return false; } 184 static inline bool hv_is_hibernation_supported(void) { return false; } 185 static inline void hyperv_cleanup(void) {} 186 #endif /* CONFIG_HYPERV */ 187 188 #endif 189