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 98 void hv_setup_kexec_handler(void (*handler)(void)); 99 void hv_remove_kexec_handler(void); 100 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); 101 void hv_remove_crash_handler(void); 102 103 extern int vmbus_interrupt; 104 extern int vmbus_irq; 105 106 #if IS_ENABLED(CONFIG_HYPERV) 107 /* 108 * Hypervisor's notion of virtual processor ID is different from 109 * Linux' notion of CPU ID. This information can only be retrieved 110 * in the context of the calling CPU. Setup a map for easy access 111 * to this information. 112 */ 113 extern u32 *hv_vp_index; 114 extern u32 hv_max_vp_index; 115 116 /* Sentinel value for an uninitialized entry in hv_vp_index array */ 117 #define VP_INVAL U32_MAX 118 119 void *hv_alloc_hyperv_page(void); 120 void *hv_alloc_hyperv_zeroed_page(void); 121 void hv_free_hyperv_page(unsigned long addr); 122 123 /** 124 * hv_cpu_number_to_vp_number() - Map CPU to VP. 125 * @cpu_number: CPU number in Linux terms 126 * 127 * This function returns the mapping between the Linux processor 128 * number and the hypervisor's virtual processor number, useful 129 * in making hypercalls and such that talk about specific 130 * processors. 131 * 132 * Return: Virtual processor number in Hyper-V terms 133 */ 134 static inline int hv_cpu_number_to_vp_number(int cpu_number) 135 { 136 return hv_vp_index[cpu_number]; 137 } 138 139 static inline int cpumask_to_vpset(struct hv_vpset *vpset, 140 const struct cpumask *cpus) 141 { 142 int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1; 143 144 /* valid_bank_mask can represent up to 64 banks */ 145 if (hv_max_vp_index / 64 >= 64) 146 return 0; 147 148 /* 149 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex 150 * structs are not cleared between calls, we risk flushing unneeded 151 * vCPUs otherwise. 152 */ 153 for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++) 154 vpset->bank_contents[vcpu_bank] = 0; 155 156 /* 157 * Some banks may end up being empty but this is acceptable. 158 */ 159 for_each_cpu(cpu, cpus) { 160 vcpu = hv_cpu_number_to_vp_number(cpu); 161 if (vcpu == VP_INVAL) 162 return -1; 163 vcpu_bank = vcpu / 64; 164 vcpu_offset = vcpu % 64; 165 __set_bit(vcpu_offset, (unsigned long *) 166 &vpset->bank_contents[vcpu_bank]); 167 if (vcpu_bank >= nr_bank) 168 nr_bank = vcpu_bank + 1; 169 } 170 vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0); 171 return nr_bank; 172 } 173 174 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die); 175 bool hv_is_hyperv_initialized(void); 176 bool hv_is_hibernation_supported(void); 177 enum hv_isolation_type hv_get_isolation_type(void); 178 bool hv_is_isolation_supported(void); 179 void hyperv_cleanup(void); 180 #else /* CONFIG_HYPERV */ 181 static inline bool hv_is_hyperv_initialized(void) { return false; } 182 static inline bool hv_is_hibernation_supported(void) { return false; } 183 static inline void hyperv_cleanup(void) {} 184 #endif /* CONFIG_HYPERV */ 185 186 #endif 187