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 185