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0cf1bfd2 MT |
1 | /* |
2 | * KVM paravirt_ops implementation | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. | |
17 | * | |
18 | * Copyright (C) 2007, Red Hat, Inc., Ingo Molnar <mingo@redhat.com> | |
19 | * Copyright IBM Corporation, 2007 | |
20 | * Authors: Anthony Liguori <aliguori@us.ibm.com> | |
21 | */ | |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/kvm_para.h> | |
26 | #include <linux/cpu.h> | |
27 | #include <linux/mm.h> | |
1da8a77b | 28 | #include <linux/highmem.h> |
096d14a3 | 29 | #include <linux/hardirq.h> |
a90ede7b | 30 | #include <asm/timer.h> |
096d14a3 MT |
31 | |
32 | #define MMU_QUEUE_SIZE 1024 | |
33 | ||
34 | struct kvm_para_state { | |
35 | u8 mmu_queue[MMU_QUEUE_SIZE]; | |
36 | int mmu_queue_len; | |
37 | enum paravirt_lazy_mode mode; | |
38 | }; | |
39 | ||
40 | static DEFINE_PER_CPU(struct kvm_para_state, para_state); | |
41 | ||
42 | static struct kvm_para_state *kvm_para_state(void) | |
43 | { | |
44 | return &per_cpu(para_state, raw_smp_processor_id()); | |
45 | } | |
0cf1bfd2 MT |
46 | |
47 | /* | |
48 | * No need for any "IO delay" on KVM | |
49 | */ | |
50 | static void kvm_io_delay(void) | |
51 | { | |
52 | } | |
53 | ||
1da8a77b MT |
54 | static void kvm_mmu_op(void *buffer, unsigned len) |
55 | { | |
56 | int r; | |
57 | unsigned long a1, a2; | |
58 | ||
59 | do { | |
60 | a1 = __pa(buffer); | |
61 | a2 = 0; /* on i386 __pa() always returns <4G */ | |
62 | r = kvm_hypercall3(KVM_HC_MMU_OP, len, a1, a2); | |
63 | buffer += r; | |
64 | len -= r; | |
65 | } while (len); | |
66 | } | |
67 | ||
096d14a3 MT |
68 | static void mmu_queue_flush(struct kvm_para_state *state) |
69 | { | |
70 | if (state->mmu_queue_len) { | |
71 | kvm_mmu_op(state->mmu_queue, state->mmu_queue_len); | |
72 | state->mmu_queue_len = 0; | |
73 | } | |
74 | } | |
75 | ||
76 | static void kvm_deferred_mmu_op(void *buffer, int len) | |
77 | { | |
78 | struct kvm_para_state *state = kvm_para_state(); | |
79 | ||
80 | if (state->mode != PARAVIRT_LAZY_MMU) { | |
81 | kvm_mmu_op(buffer, len); | |
82 | return; | |
83 | } | |
84 | if (state->mmu_queue_len + len > sizeof state->mmu_queue) | |
85 | mmu_queue_flush(state); | |
86 | memcpy(state->mmu_queue + state->mmu_queue_len, buffer, len); | |
87 | state->mmu_queue_len += len; | |
88 | } | |
89 | ||
1da8a77b MT |
90 | static void kvm_mmu_write(void *dest, u64 val) |
91 | { | |
92 | __u64 pte_phys; | |
93 | struct kvm_mmu_op_write_pte wpte; | |
94 | ||
95 | #ifdef CONFIG_HIGHPTE | |
96 | struct page *page; | |
97 | unsigned long dst = (unsigned long) dest; | |
98 | ||
99 | page = kmap_atomic_to_page(dest); | |
100 | pte_phys = page_to_pfn(page); | |
101 | pte_phys <<= PAGE_SHIFT; | |
102 | pte_phys += (dst & ~(PAGE_MASK)); | |
103 | #else | |
104 | pte_phys = (unsigned long)__pa(dest); | |
105 | #endif | |
106 | wpte.header.op = KVM_MMU_OP_WRITE_PTE; | |
107 | wpte.pte_val = val; | |
108 | wpte.pte_phys = pte_phys; | |
109 | ||
096d14a3 | 110 | kvm_deferred_mmu_op(&wpte, sizeof wpte); |
1da8a77b MT |
111 | } |
112 | ||
113 | /* | |
114 | * We only need to hook operations that are MMU writes. We hook these so that | |
115 | * we can use lazy MMU mode to batch these operations. We could probably | |
116 | * improve the performance of the host code if we used some of the information | |
117 | * here to simplify processing of batched writes. | |
118 | */ | |
119 | static void kvm_set_pte(pte_t *ptep, pte_t pte) | |
120 | { | |
121 | kvm_mmu_write(ptep, pte_val(pte)); | |
122 | } | |
123 | ||
124 | static void kvm_set_pte_at(struct mm_struct *mm, unsigned long addr, | |
125 | pte_t *ptep, pte_t pte) | |
126 | { | |
127 | kvm_mmu_write(ptep, pte_val(pte)); | |
128 | } | |
129 | ||
130 | static void kvm_set_pmd(pmd_t *pmdp, pmd_t pmd) | |
131 | { | |
132 | kvm_mmu_write(pmdp, pmd_val(pmd)); | |
133 | } | |
134 | ||
135 | #if PAGETABLE_LEVELS >= 3 | |
136 | #ifdef CONFIG_X86_PAE | |
137 | static void kvm_set_pte_atomic(pte_t *ptep, pte_t pte) | |
138 | { | |
139 | kvm_mmu_write(ptep, pte_val(pte)); | |
140 | } | |
141 | ||
1da8a77b MT |
142 | static void kvm_pte_clear(struct mm_struct *mm, |
143 | unsigned long addr, pte_t *ptep) | |
144 | { | |
145 | kvm_mmu_write(ptep, 0); | |
146 | } | |
147 | ||
148 | static void kvm_pmd_clear(pmd_t *pmdp) | |
149 | { | |
150 | kvm_mmu_write(pmdp, 0); | |
151 | } | |
152 | #endif | |
153 | ||
154 | static void kvm_set_pud(pud_t *pudp, pud_t pud) | |
155 | { | |
156 | kvm_mmu_write(pudp, pud_val(pud)); | |
157 | } | |
158 | ||
159 | #if PAGETABLE_LEVELS == 4 | |
160 | static void kvm_set_pgd(pgd_t *pgdp, pgd_t pgd) | |
161 | { | |
162 | kvm_mmu_write(pgdp, pgd_val(pgd)); | |
163 | } | |
164 | #endif | |
165 | #endif /* PAGETABLE_LEVELS >= 3 */ | |
166 | ||
167 | static void kvm_flush_tlb(void) | |
168 | { | |
169 | struct kvm_mmu_op_flush_tlb ftlb = { | |
170 | .header.op = KVM_MMU_OP_FLUSH_TLB, | |
171 | }; | |
172 | ||
096d14a3 | 173 | kvm_deferred_mmu_op(&ftlb, sizeof ftlb); |
1da8a77b MT |
174 | } |
175 | ||
f8639939 | 176 | static void kvm_release_pt(unsigned long pfn) |
1da8a77b MT |
177 | { |
178 | struct kvm_mmu_op_release_pt rpt = { | |
179 | .header.op = KVM_MMU_OP_RELEASE_PT, | |
180 | .pt_phys = (u64)pfn << PAGE_SHIFT, | |
181 | }; | |
182 | ||
183 | kvm_mmu_op(&rpt, sizeof rpt); | |
184 | } | |
185 | ||
096d14a3 MT |
186 | static void kvm_enter_lazy_mmu(void) |
187 | { | |
188 | struct kvm_para_state *state = kvm_para_state(); | |
189 | ||
190 | paravirt_enter_lazy_mmu(); | |
191 | state->mode = paravirt_get_lazy_mode(); | |
192 | } | |
193 | ||
194 | static void kvm_leave_lazy_mmu(void) | |
195 | { | |
196 | struct kvm_para_state *state = kvm_para_state(); | |
197 | ||
198 | mmu_queue_flush(state); | |
b407fc57 | 199 | paravirt_leave_lazy_mmu(); |
096d14a3 MT |
200 | state->mode = paravirt_get_lazy_mode(); |
201 | } | |
202 | ||
0cf1bfd2 MT |
203 | static void paravirt_ops_setup(void) |
204 | { | |
205 | pv_info.name = "KVM"; | |
206 | pv_info.paravirt_enabled = 1; | |
207 | ||
208 | if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY)) | |
209 | pv_cpu_ops.io_delay = kvm_io_delay; | |
210 | ||
1da8a77b MT |
211 | if (kvm_para_has_feature(KVM_FEATURE_MMU_OP)) { |
212 | pv_mmu_ops.set_pte = kvm_set_pte; | |
213 | pv_mmu_ops.set_pte_at = kvm_set_pte_at; | |
214 | pv_mmu_ops.set_pmd = kvm_set_pmd; | |
215 | #if PAGETABLE_LEVELS >= 3 | |
216 | #ifdef CONFIG_X86_PAE | |
217 | pv_mmu_ops.set_pte_atomic = kvm_set_pte_atomic; | |
1da8a77b MT |
218 | pv_mmu_ops.pte_clear = kvm_pte_clear; |
219 | pv_mmu_ops.pmd_clear = kvm_pmd_clear; | |
220 | #endif | |
221 | pv_mmu_ops.set_pud = kvm_set_pud; | |
222 | #if PAGETABLE_LEVELS == 4 | |
223 | pv_mmu_ops.set_pgd = kvm_set_pgd; | |
224 | #endif | |
225 | #endif | |
226 | pv_mmu_ops.flush_tlb_user = kvm_flush_tlb; | |
227 | pv_mmu_ops.release_pte = kvm_release_pt; | |
228 | pv_mmu_ops.release_pmd = kvm_release_pt; | |
229 | pv_mmu_ops.release_pud = kvm_release_pt; | |
096d14a3 MT |
230 | |
231 | pv_mmu_ops.lazy_mode.enter = kvm_enter_lazy_mmu; | |
232 | pv_mmu_ops.lazy_mode.leave = kvm_leave_lazy_mmu; | |
1da8a77b | 233 | } |
a90ede7b MT |
234 | #ifdef CONFIG_X86_IO_APIC |
235 | no_timer_check = 1; | |
236 | #endif | |
0cf1bfd2 MT |
237 | } |
238 | ||
239 | void __init kvm_guest_init(void) | |
240 | { | |
241 | if (!kvm_para_available()) | |
242 | return; | |
243 | ||
244 | paravirt_ops_setup(); | |
245 | } |