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 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
hyperv_flush_tlb_others(const struct cpumask * cpus,const struct flush_tlb_info * info)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 if (cpumask_empty(cpus))
70 return;
71
72 local_irq_save(flags);
73
74 flush_pcpu = (struct hv_tlb_flush **)
75 this_cpu_ptr(hyperv_pcpu_input_arg);
76
77 flush = *flush_pcpu;
78
79 if (unlikely(!flush)) {
80 local_irq_restore(flags);
81 goto do_native;
82 }
83
84 if (info->mm) {
85 /*
86 * AddressSpace argument must match the CR3 with PCID bits
87 * stripped out.
88 */
89 flush->address_space = virt_to_phys(info->mm->pgd);
90 flush->address_space &= CR3_ADDR_MASK;
91 flush->flags = 0;
92 } else {
93 flush->address_space = 0;
94 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
95 }
96
97 flush->processor_mask = 0;
98 if (cpumask_equal(cpus, cpu_present_mask)) {
99 flush->flags |= HV_FLUSH_ALL_PROCESSORS;
100 } else {
101 /*
102 * From the supplied CPU set we need to figure out if we can get
103 * away with cheaper HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}
104 * hypercalls. This is possible when the highest VP number in
105 * the set is < 64. As VP numbers are usually in ascending order
106 * and match Linux CPU ids, here is an optimization: we check
107 * the VP number for the highest bit in the supplied set first
108 * so we can quickly find out if using *_EX hypercalls is a
109 * must. We will also check all VP numbers when walking the
110 * supplied CPU set to remain correct in all cases.
111 */
112 if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64)
113 goto do_ex_hypercall;
114
115 for_each_cpu(cpu, cpus) {
116 vcpu = hv_cpu_number_to_vp_number(cpu);
117 if (vcpu == VP_INVAL) {
118 local_irq_restore(flags);
119 goto do_native;
120 }
121
122 if (vcpu >= 64)
123 goto do_ex_hypercall;
124
125 __set_bit(vcpu, (unsigned long *)
126 &flush->processor_mask);
127 }
128 }
129
130 /*
131 * We can flush not more than max_gvas with one hypercall. Flush the
132 * whole address space if we were asked to do more.
133 */
134 max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]);
135
136 if (info->end == TLB_FLUSH_ALL) {
137 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
138 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
139 flush, NULL);
140 } else if (info->end &&
141 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
142 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
143 flush, NULL);
144 } else {
145 gva_n = fill_gva_list(flush->gva_list, 0,
146 info->start, info->end);
147 status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST,
148 gva_n, 0, flush, NULL);
149 }
150 goto check_status;
151
152 do_ex_hypercall:
153 status = hyperv_flush_tlb_others_ex(cpus, info);
154
155 check_status:
156 local_irq_restore(flags);
157
158 if (!(status & HV_HYPERCALL_RESULT_MASK))
159 return;
160 do_native:
161 native_flush_tlb_others(cpus, info);
162 }
163
hyperv_flush_tlb_others_ex(const struct cpumask * cpus,const struct flush_tlb_info * info)164 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
165 const struct flush_tlb_info *info)
166 {
167 int nr_bank = 0, max_gvas, gva_n;
168 struct hv_tlb_flush_ex **flush_pcpu;
169 struct hv_tlb_flush_ex *flush;
170 u64 status;
171
172 if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
173 return U64_MAX;
174
175 flush_pcpu = (struct hv_tlb_flush_ex **)
176 this_cpu_ptr(hyperv_pcpu_input_arg);
177
178 flush = *flush_pcpu;
179
180 if (info->mm) {
181 /*
182 * AddressSpace argument must match the CR3 with PCID bits
183 * stripped out.
184 */
185 flush->address_space = virt_to_phys(info->mm->pgd);
186 flush->address_space &= CR3_ADDR_MASK;
187 flush->flags = 0;
188 } else {
189 flush->address_space = 0;
190 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
191 }
192
193 flush->hv_vp_set.valid_bank_mask = 0;
194
195 flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K;
196 nr_bank = cpumask_to_vpset(&(flush->hv_vp_set), cpus);
197 if (nr_bank < 0)
198 return U64_MAX;
199
200 /*
201 * We can flush not more than max_gvas with one hypercall. Flush the
202 * whole address space if we were asked to do more.
203 */
204 max_gvas =
205 (PAGE_SIZE - sizeof(*flush) - nr_bank *
206 sizeof(flush->hv_vp_set.bank_contents[0])) /
207 sizeof(flush->gva_list[0]);
208
209 if (info->end == TLB_FLUSH_ALL) {
210 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
211 status = hv_do_rep_hypercall(
212 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
213 0, nr_bank, flush, NULL);
214 } else if (info->end &&
215 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
216 status = hv_do_rep_hypercall(
217 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
218 0, nr_bank, flush, NULL);
219 } else {
220 gva_n = fill_gva_list(flush->gva_list, nr_bank,
221 info->start, info->end);
222 status = hv_do_rep_hypercall(
223 HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX,
224 gva_n, nr_bank, flush, NULL);
225 }
226
227 return status;
228 }
229
hyperv_setup_mmu_ops(void)230 void hyperv_setup_mmu_ops(void)
231 {
232 if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
233 return;
234
235 pr_info("Using hypercall for remote TLB flush\n");
236 pv_ops.mmu.flush_tlb_others = hyperv_flush_tlb_others;
237 pv_ops.mmu.tlb_remove_table = tlb_remove_table;
238 }
239
