1 #define pr_fmt(fmt) "Hyper-V: " fmt 2 3 #include <linux/hyperv.h> 4 #include <linux/log2.h> 5 #include <linux/slab.h> 6 #include <linux/types.h> 7 8 #include <asm/fpu/api.h> 9 #include <asm/mshyperv.h> 10 #include <asm/msr.h> 11 #include <asm/tlbflush.h> 12 #include <asm/tlb.h> 13 14 #define CREATE_TRACE_POINTS 15 #include <asm/trace/hyperv.h> 16 17 /* Each gva in gva_list encodes up to 4096 pages to flush */ 18 #define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE) 19 20 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus, 21 const struct flush_tlb_info *info); 22 23 /* 24 * Fills in gva_list starting from offset. Returns the number of items added. 25 */ 26 static inline int fill_gva_list(u64 gva_list[], int offset, 27 unsigned long start, unsigned long end) 28 { 29 int gva_n = offset; 30 unsigned long cur = start, diff; 31 32 do { 33 diff = end > cur ? end - cur : 0; 34 35 gva_list[gva_n] = cur & PAGE_MASK; 36 /* 37 * Lower 12 bits encode the number of additional 38 * pages to flush (in addition to the 'cur' page). 39 */ 40 if (diff >= HV_TLB_FLUSH_UNIT) { 41 gva_list[gva_n] |= ~PAGE_MASK; 42 cur += HV_TLB_FLUSH_UNIT; 43 } else if (diff) { 44 gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT; 45 cur = end; 46 } 47 48 gva_n++; 49 50 } while (cur < end); 51 52 return gva_n - offset; 53 } 54 55 static void hyperv_flush_tlb_others(const struct cpumask *cpus, 56 const struct flush_tlb_info *info) 57 { 58 int cpu, vcpu, gva_n, max_gvas; 59 struct hv_tlb_flush **flush_pcpu; 60 struct hv_tlb_flush *flush; 61 u64 status = U64_MAX; 62 unsigned long flags; 63 64 trace_hyperv_mmu_flush_tlb_others(cpus, info); 65 66 if (!hv_hypercall_pg) 67 goto do_native; 68 69 local_irq_save(flags); 70 71 /* 72 * Only check the mask _after_ interrupt has been disabled to avoid the 73 * mask changing under our feet. 74 */ 75 if (cpumask_empty(cpus)) { 76 local_irq_restore(flags); 77 return; 78 } 79 80 flush_pcpu = (struct hv_tlb_flush **) 81 this_cpu_ptr(hyperv_pcpu_input_arg); 82 83 flush = *flush_pcpu; 84 85 if (unlikely(!flush)) { 86 local_irq_restore(flags); 87 goto do_native; 88 } 89 90 if (info->mm) { 91 /* 92 * AddressSpace argument must match the CR3 with PCID bits 93 * stripped out. 94 */ 95 flush->address_space = virt_to_phys(info->mm->pgd); 96 flush->address_space &= CR3_ADDR_MASK; 97 flush->flags = 0; 98 } else { 99 flush->address_space = 0; 100 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES; 101 } 102 103 flush->processor_mask = 0; 104 if (cpumask_equal(cpus, cpu_present_mask)) { 105 flush->flags |= HV_FLUSH_ALL_PROCESSORS; 106 } else { 107 /* 108 * From the supplied CPU set we need to figure out if we can get 109 * away with cheaper HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} 110 * hypercalls. This is possible when the highest VP number in 111 * the set is < 64. As VP numbers are usually in ascending order 112 * and match Linux CPU ids, here is an optimization: we check 113 * the VP number for the highest bit in the supplied set first 114 * so we can quickly find out if using *_EX hypercalls is a 115 * must. We will also check all VP numbers when walking the 116 * supplied CPU set to remain correct in all cases. 117 */ 118 if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64) 119 goto do_ex_hypercall; 120 121 for_each_cpu(cpu, cpus) { 122 vcpu = hv_cpu_number_to_vp_number(cpu); 123 if (vcpu == VP_INVAL) { 124 local_irq_restore(flags); 125 goto do_native; 126 } 127 128 if (vcpu >= 64) 129 goto do_ex_hypercall; 130 131 __set_bit(vcpu, (unsigned long *) 132 &flush->processor_mask); 133 } 134 } 135 136 /* 137 * We can flush not more than max_gvas with one hypercall. Flush the 138 * whole address space if we were asked to do more. 139 */ 140 max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]); 141 142 if (info->end == TLB_FLUSH_ALL) { 143 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY; 144 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE, 145 flush, NULL); 146 } else if (info->end && 147 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) { 148 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE, 149 flush, NULL); 150 } else { 151 gva_n = fill_gva_list(flush->gva_list, 0, 152 info->start, info->end); 153 status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST, 154 gva_n, 0, flush, NULL); 155 } 156 goto check_status; 157 158 do_ex_hypercall: 159 status = hyperv_flush_tlb_others_ex(cpus, info); 160 161 check_status: 162 local_irq_restore(flags); 163 164 if (!(status & HV_HYPERCALL_RESULT_MASK)) 165 return; 166 do_native: 167 native_flush_tlb_others(cpus, info); 168 } 169 170 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus, 171 const struct flush_tlb_info *info) 172 { 173 int nr_bank = 0, max_gvas, gva_n; 174 struct hv_tlb_flush_ex **flush_pcpu; 175 struct hv_tlb_flush_ex *flush; 176 u64 status; 177 178 if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) 179 return U64_MAX; 180 181 flush_pcpu = (struct hv_tlb_flush_ex **) 182 this_cpu_ptr(hyperv_pcpu_input_arg); 183 184 flush = *flush_pcpu; 185 186 if (info->mm) { 187 /* 188 * AddressSpace argument must match the CR3 with PCID bits 189 * stripped out. 190 */ 191 flush->address_space = virt_to_phys(info->mm->pgd); 192 flush->address_space &= CR3_ADDR_MASK; 193 flush->flags = 0; 194 } else { 195 flush->address_space = 0; 196 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES; 197 } 198 199 flush->hv_vp_set.valid_bank_mask = 0; 200 201 flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K; 202 nr_bank = cpumask_to_vpset(&(flush->hv_vp_set), cpus); 203 if (nr_bank < 0) 204 return U64_MAX; 205 206 /* 207 * We can flush not more than max_gvas with one hypercall. Flush the 208 * whole address space if we were asked to do more. 209 */ 210 max_gvas = 211 (PAGE_SIZE - sizeof(*flush) - nr_bank * 212 sizeof(flush->hv_vp_set.bank_contents[0])) / 213 sizeof(flush->gva_list[0]); 214 215 if (info->end == TLB_FLUSH_ALL) { 216 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY; 217 status = hv_do_rep_hypercall( 218 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX, 219 0, nr_bank, flush, NULL); 220 } else if (info->end && 221 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) { 222 status = hv_do_rep_hypercall( 223 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX, 224 0, nr_bank, flush, NULL); 225 } else { 226 gva_n = fill_gva_list(flush->gva_list, nr_bank, 227 info->start, info->end); 228 status = hv_do_rep_hypercall( 229 HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX, 230 gva_n, nr_bank, flush, NULL); 231 } 232 233 return status; 234 } 235 236 void hyperv_setup_mmu_ops(void) 237 { 238 if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED)) 239 return; 240 241 pr_info("Using hypercall for remote TLB flush\n"); 242 pv_ops.mmu.flush_tlb_others = hyperv_flush_tlb_others; 243 pv_ops.mmu.tlb_remove_table = tlb_remove_table; 244 } 245