summaryrefslogtreecommitdiffstats
path: root/arch/x86/hyperv/mmu.c
blob: de27615c51ea3fe951c2d2065734b5a79693c00a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
#define pr_fmt(fmt)  "Hyper-V: " fmt

#include <linux/hyperv.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <asm/fpu/api.h>
#include <asm/mshyperv.h>
#include <asm/msr.h>
#include <asm/tlbflush.h>

#define CREATE_TRACE_POINTS
#include <asm/trace/hyperv.h>

/* Each gva in gva_list encodes up to 4096 pages to flush */
#define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE)


/*
 * Fills in gva_list starting from offset. Returns the number of items added.
 */
static inline int fill_gva_list(u64 gva_list[], int offset,
				unsigned long start, unsigned long end)
{
	int gva_n = offset;
	unsigned long cur = start, diff;

	do {
		diff = end > cur ? end - cur : 0;

		gva_list[gva_n] = cur & PAGE_MASK;
		/*
		 * Lower 12 bits encode the number of additional
		 * pages to flush (in addition to the 'cur' page).
		 */
		if (diff >= HV_TLB_FLUSH_UNIT)
			gva_list[gva_n] |= ~PAGE_MASK;
		else if (diff)
			gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT;

		cur += HV_TLB_FLUSH_UNIT;
		gva_n++;

	} while (cur < end);

	return gva_n - offset;
}

static void hyperv_flush_tlb_others(const struct cpumask *cpus,
				    const struct flush_tlb_info *info)
{
	int cpu, vcpu, gva_n, max_gvas;
	struct hv_tlb_flush **flush_pcpu;
	struct hv_tlb_flush *flush;
	u64 status = U64_MAX;
	unsigned long flags;

	trace_hyperv_mmu_flush_tlb_others(cpus, info);

	if (!hv_hypercall_pg)
		goto do_native;

	if (cpumask_empty(cpus))
		return;

	local_irq_save(flags);

	flush_pcpu = (struct hv_tlb_flush **)
		     this_cpu_ptr(hyperv_pcpu_input_arg);

	flush = *flush_pcpu;

	if (unlikely(!flush)) {
		local_irq_restore(flags);
		goto do_native;
	}

	if (info->mm) {
		/*
		 * AddressSpace argument must match the CR3 with PCID bits
		 * stripped out.
		 */
		flush->address_space = virt_to_phys(info->mm->pgd);
		flush->address_space &= CR3_ADDR_MASK;
		flush->flags = 0;
	} else {
		flush->address_space = 0;
		flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
	}

	flush->processor_mask = 0;
	if (cpumask_equal(cpus, cpu_present_mask)) {
		flush->flags |= HV_FLUSH_ALL_PROCESSORS;
	} else {
		for_each_cpu(cpu, cpus) {
			vcpu = hv_cpu_number_to_vp_number(cpu);
			if (vcpu >= 64)
				goto do_native;

			__set_bit(vcpu, (unsigned long *)
				  &flush->processor_mask);
		}
	}

	/*
	 * We can flush not more than max_gvas with one hypercall. Flush the
	 * whole address space if we were asked to do more.
	 */
	max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]);

	if (info->end == TLB_FLUSH_ALL) {
		flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
		status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
					 flush, NULL);
	} else if (info->end &&
		   ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
		status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
					 flush, NULL);
	} else {
		gva_n = fill_gva_list(flush->gva_list, 0,
				      info->start, info->end);
		status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST,
					     gva_n, 0, flush, NULL);
	}

	local_irq_restore(flags);

	if (!(status & HV_HYPERCALL_RESULT_MASK))
		return;
do_native:
	native_flush_tlb_others(cpus, info);
}

static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
				       const struct flush_tlb_info *info)
{
	int nr_bank = 0, max_gvas, gva_n;
	struct hv_tlb_flush_ex **flush_pcpu;
	struct hv_tlb_flush_ex *flush;
	u64 status = U64_MAX;
	unsigned long flags;

	trace_hyperv_mmu_flush_tlb_others(cpus, info);

	if (!hv_hypercall_pg)
		goto do_native;

	if (cpumask_empty(cpus))
		return;

	local_irq_save(flags);

	flush_pcpu = (struct hv_tlb_flush_ex **)
		     this_cpu_ptr(hyperv_pcpu_input_arg);

	flush = *flush_pcpu;

	if (unlikely(!flush)) {
		local_irq_restore(flags);
		goto do_native;
	}

	if (info->mm) {
		/*
		 * AddressSpace argument must match the CR3 with PCID bits
		 * stripped out.
		 */
		flush->address_space = virt_to_phys(info->mm->pgd);
		flush->address_space &= CR3_ADDR_MASK;
		flush->flags = 0;
	} else {
		flush->address_space = 0;
		flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
	}

	flush->hv_vp_set.valid_bank_mask = 0;

	if (!cpumask_equal(cpus, cpu_present_mask)) {
		flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K;
		nr_bank = cpumask_to_vpset(&(flush->hv_vp_set), cpus);
	}

	if (!nr_bank) {
		flush->hv_vp_set.format = HV_GENERIC_SET_ALL;
		flush->flags |= HV_FLUSH_ALL_PROCESSORS;
	}

	/*
	 * We can flush not more than max_gvas with one hypercall. Flush the
	 * whole address space if we were asked to do more.
	 */
	max_gvas =
		(PAGE_SIZE - sizeof(*flush) - nr_bank *
		 sizeof(flush->hv_vp_set.bank_contents[0])) /
		sizeof(flush->gva_list[0]);

	if (info->end == TLB_FLUSH_ALL) {
		flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
		status = hv_do_rep_hypercall(
			HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
			0, nr_bank, flush, NULL);
	} else if (info->end &&
		   ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
		status = hv_do_rep_hypercall(
			HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
			0, nr_bank, flush, NULL);
	} else {
		gva_n = fill_gva_list(flush->gva_list, nr_bank,
				      info->start, info->end);
		status = hv_do_rep_hypercall(
			HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX,
			gva_n, nr_bank, flush, NULL);
	}

	local_irq_restore(flags);

	if (!(status & HV_HYPERCALL_RESULT_MASK))
		return;
do_native:
	native_flush_tlb_others(cpus, info);
}

void hyperv_setup_mmu_ops(void)
{
	if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
		return;

	if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) {
		pr_info("Using hypercall for remote TLB flush\n");
		pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others;
	} else {
		pr_info("Using ext hypercall for remote TLB flush\n");
		pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others_ex;
	}
}