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 */
fill_gva_list(u64 gva_list[],int offset,unsigned long start,unsigned long end)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 else if (diff)
43 gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT;
44
45 cur += HV_TLB_FLUSH_UNIT;
46 gva_n++;
47
48 } while (cur < end);
49
50 return gva_n - offset;
51 }
52
hyperv_flush_tlb_others(const struct cpumask * cpus,const struct flush_tlb_info * info)53 static void hyperv_flush_tlb_others(const struct cpumask *cpus,
54 const struct flush_tlb_info *info)
55 {
56 int cpu, vcpu, gva_n, max_gvas;
57 struct hv_tlb_flush **flush_pcpu;
58 struct hv_tlb_flush *flush;
59 u64 status = U64_MAX;
60 unsigned long flags;
61
62 trace_hyperv_mmu_flush_tlb_others(cpus, info);
63
64 if (!hv_hypercall_pg)
65 goto do_native;
66
67 if (cpumask_empty(cpus))
68 return;
69
70 local_irq_save(flags);
71
72 flush_pcpu = (struct hv_tlb_flush **)
73 this_cpu_ptr(hyperv_pcpu_input_arg);
74
75 flush = *flush_pcpu;
76
77 if (unlikely(!flush)) {
78 local_irq_restore(flags);
79 goto do_native;
80 }
81
82 if (info->mm) {
83 /*
84 * AddressSpace argument must match the CR3 with PCID bits
85 * stripped out.
86 */
87 flush->address_space = virt_to_phys(info->mm->pgd);
88 flush->address_space &= CR3_ADDR_MASK;
89 flush->flags = 0;
90 } else {
91 flush->address_space = 0;
92 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
93 }
94
95 flush->processor_mask = 0;
96 if (cpumask_equal(cpus, cpu_present_mask)) {
97 flush->flags |= HV_FLUSH_ALL_PROCESSORS;
98 } else {
99 /*
100 * From the supplied CPU set we need to figure out if we can get
101 * away with cheaper HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}
102 * hypercalls. This is possible when the highest VP number in
103 * the set is < 64. As VP numbers are usually in ascending order
104 * and match Linux CPU ids, here is an optimization: we check
105 * the VP number for the highest bit in the supplied set first
106 * so we can quickly find out if using *_EX hypercalls is a
107 * must. We will also check all VP numbers when walking the
108 * supplied CPU set to remain correct in all cases.
109 */
110 if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64)
111 goto do_ex_hypercall;
112
113 for_each_cpu(cpu, cpus) {
114 vcpu = hv_cpu_number_to_vp_number(cpu);
115 if (vcpu == VP_INVAL) {
116 local_irq_restore(flags);
117 goto do_native;
118 }
119
120 if (vcpu >= 64)
121 goto do_ex_hypercall;
122
123 __set_bit(vcpu, (unsigned long *)
124 &flush->processor_mask);
125 }
126 }
127
128 /*
129 * We can flush not more than max_gvas with one hypercall. Flush the
130 * whole address space if we were asked to do more.
131 */
132 max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]);
133
134 if (info->end == TLB_FLUSH_ALL) {
135 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
136 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
137 flush, NULL);
138 } else if (info->end &&
139 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
140 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
141 flush, NULL);
142 } else {
143 gva_n = fill_gva_list(flush->gva_list, 0,
144 info->start, info->end);
145 status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST,
146 gva_n, 0, flush, NULL);
147 }
148 goto check_status;
149
150 do_ex_hypercall:
151 status = hyperv_flush_tlb_others_ex(cpus, info);
152
153 check_status:
154 local_irq_restore(flags);
155
156 if (!(status & HV_HYPERCALL_RESULT_MASK))
157 return;
158 do_native:
159 native_flush_tlb_others(cpus, info);
160 }
161
hyperv_flush_tlb_others_ex(const struct cpumask * cpus,const struct flush_tlb_info * info)162 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
163 const struct flush_tlb_info *info)
164 {
165 int nr_bank = 0, max_gvas, gva_n;
166 struct hv_tlb_flush_ex **flush_pcpu;
167 struct hv_tlb_flush_ex *flush;
168 u64 status;
169
170 if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
171 return U64_MAX;
172
173 flush_pcpu = (struct hv_tlb_flush_ex **)
174 this_cpu_ptr(hyperv_pcpu_input_arg);
175
176 flush = *flush_pcpu;
177
178 if (info->mm) {
179 /*
180 * AddressSpace argument must match the CR3 with PCID bits
181 * stripped out.
182 */
183 flush->address_space = virt_to_phys(info->mm->pgd);
184 flush->address_space &= CR3_ADDR_MASK;
185 flush->flags = 0;
186 } else {
187 flush->address_space = 0;
188 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
189 }
190
191 flush->hv_vp_set.valid_bank_mask = 0;
192
193 flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K;
194 nr_bank = cpumask_to_vpset(&(flush->hv_vp_set), cpus);
195 if (nr_bank < 0)
196 return U64_MAX;
197
198 /*
199 * We can flush not more than max_gvas with one hypercall. Flush the
200 * whole address space if we were asked to do more.
201 */
202 max_gvas =
203 (PAGE_SIZE - sizeof(*flush) - nr_bank *
204 sizeof(flush->hv_vp_set.bank_contents[0])) /
205 sizeof(flush->gva_list[0]);
206
207 if (info->end == TLB_FLUSH_ALL) {
208 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
209 status = hv_do_rep_hypercall(
210 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
211 0, nr_bank, flush, NULL);
212 } else if (info->end &&
213 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
214 status = hv_do_rep_hypercall(
215 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
216 0, nr_bank, flush, NULL);
217 } else {
218 gva_n = fill_gva_list(flush->gva_list, nr_bank,
219 info->start, info->end);
220 status = hv_do_rep_hypercall(
221 HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX,
222 gva_n, nr_bank, flush, NULL);
223 }
224
225 return status;
226 }
227
hyperv_setup_mmu_ops(void)228 void hyperv_setup_mmu_ops(void)
229 {
230 if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
231 return;
232
233 pr_info("Using hypercall for remote TLB flush\n");
234 pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others;
235 pv_mmu_ops.tlb_remove_table = tlb_remove_table;
236 }
237
