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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> |
0cf1bfd2 MT |
29 | |
30 | /* | |
31 | * No need for any "IO delay" on KVM | |
32 | */ | |
33 | static void kvm_io_delay(void) | |
34 | { | |
35 | } | |
36 | ||
1da8a77b MT |
37 | static void kvm_mmu_op(void *buffer, unsigned len) |
38 | { | |
39 | int r; | |
40 | unsigned long a1, a2; | |
41 | ||
42 | do { | |
43 | a1 = __pa(buffer); | |
44 | a2 = 0; /* on i386 __pa() always returns <4G */ | |
45 | r = kvm_hypercall3(KVM_HC_MMU_OP, len, a1, a2); | |
46 | buffer += r; | |
47 | len -= r; | |
48 | } while (len); | |
49 | } | |
50 | ||
51 | static void kvm_mmu_write(void *dest, u64 val) | |
52 | { | |
53 | __u64 pte_phys; | |
54 | struct kvm_mmu_op_write_pte wpte; | |
55 | ||
56 | #ifdef CONFIG_HIGHPTE | |
57 | struct page *page; | |
58 | unsigned long dst = (unsigned long) dest; | |
59 | ||
60 | page = kmap_atomic_to_page(dest); | |
61 | pte_phys = page_to_pfn(page); | |
62 | pte_phys <<= PAGE_SHIFT; | |
63 | pte_phys += (dst & ~(PAGE_MASK)); | |
64 | #else | |
65 | pte_phys = (unsigned long)__pa(dest); | |
66 | #endif | |
67 | wpte.header.op = KVM_MMU_OP_WRITE_PTE; | |
68 | wpte.pte_val = val; | |
69 | wpte.pte_phys = pte_phys; | |
70 | ||
71 | kvm_mmu_op(&wpte, sizeof wpte); | |
72 | } | |
73 | ||
74 | /* | |
75 | * We only need to hook operations that are MMU writes. We hook these so that | |
76 | * we can use lazy MMU mode to batch these operations. We could probably | |
77 | * improve the performance of the host code if we used some of the information | |
78 | * here to simplify processing of batched writes. | |
79 | */ | |
80 | static void kvm_set_pte(pte_t *ptep, pte_t pte) | |
81 | { | |
82 | kvm_mmu_write(ptep, pte_val(pte)); | |
83 | } | |
84 | ||
85 | static void kvm_set_pte_at(struct mm_struct *mm, unsigned long addr, | |
86 | pte_t *ptep, pte_t pte) | |
87 | { | |
88 | kvm_mmu_write(ptep, pte_val(pte)); | |
89 | } | |
90 | ||
91 | static void kvm_set_pmd(pmd_t *pmdp, pmd_t pmd) | |
92 | { | |
93 | kvm_mmu_write(pmdp, pmd_val(pmd)); | |
94 | } | |
95 | ||
96 | #if PAGETABLE_LEVELS >= 3 | |
97 | #ifdef CONFIG_X86_PAE | |
98 | static void kvm_set_pte_atomic(pte_t *ptep, pte_t pte) | |
99 | { | |
100 | kvm_mmu_write(ptep, pte_val(pte)); | |
101 | } | |
102 | ||
103 | static void kvm_set_pte_present(struct mm_struct *mm, unsigned long addr, | |
104 | pte_t *ptep, pte_t pte) | |
105 | { | |
106 | kvm_mmu_write(ptep, pte_val(pte)); | |
107 | } | |
108 | ||
109 | static void kvm_pte_clear(struct mm_struct *mm, | |
110 | unsigned long addr, pte_t *ptep) | |
111 | { | |
112 | kvm_mmu_write(ptep, 0); | |
113 | } | |
114 | ||
115 | static void kvm_pmd_clear(pmd_t *pmdp) | |
116 | { | |
117 | kvm_mmu_write(pmdp, 0); | |
118 | } | |
119 | #endif | |
120 | ||
121 | static void kvm_set_pud(pud_t *pudp, pud_t pud) | |
122 | { | |
123 | kvm_mmu_write(pudp, pud_val(pud)); | |
124 | } | |
125 | ||
126 | #if PAGETABLE_LEVELS == 4 | |
127 | static void kvm_set_pgd(pgd_t *pgdp, pgd_t pgd) | |
128 | { | |
129 | kvm_mmu_write(pgdp, pgd_val(pgd)); | |
130 | } | |
131 | #endif | |
132 | #endif /* PAGETABLE_LEVELS >= 3 */ | |
133 | ||
134 | static void kvm_flush_tlb(void) | |
135 | { | |
136 | struct kvm_mmu_op_flush_tlb ftlb = { | |
137 | .header.op = KVM_MMU_OP_FLUSH_TLB, | |
138 | }; | |
139 | ||
140 | kvm_mmu_op(&ftlb, sizeof ftlb); | |
141 | } | |
142 | ||
143 | static void kvm_release_pt(u32 pfn) | |
144 | { | |
145 | struct kvm_mmu_op_release_pt rpt = { | |
146 | .header.op = KVM_MMU_OP_RELEASE_PT, | |
147 | .pt_phys = (u64)pfn << PAGE_SHIFT, | |
148 | }; | |
149 | ||
150 | kvm_mmu_op(&rpt, sizeof rpt); | |
151 | } | |
152 | ||
0cf1bfd2 MT |
153 | static void paravirt_ops_setup(void) |
154 | { | |
155 | pv_info.name = "KVM"; | |
156 | pv_info.paravirt_enabled = 1; | |
157 | ||
158 | if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY)) | |
159 | pv_cpu_ops.io_delay = kvm_io_delay; | |
160 | ||
1da8a77b MT |
161 | if (kvm_para_has_feature(KVM_FEATURE_MMU_OP)) { |
162 | pv_mmu_ops.set_pte = kvm_set_pte; | |
163 | pv_mmu_ops.set_pte_at = kvm_set_pte_at; | |
164 | pv_mmu_ops.set_pmd = kvm_set_pmd; | |
165 | #if PAGETABLE_LEVELS >= 3 | |
166 | #ifdef CONFIG_X86_PAE | |
167 | pv_mmu_ops.set_pte_atomic = kvm_set_pte_atomic; | |
168 | pv_mmu_ops.set_pte_present = kvm_set_pte_present; | |
169 | pv_mmu_ops.pte_clear = kvm_pte_clear; | |
170 | pv_mmu_ops.pmd_clear = kvm_pmd_clear; | |
171 | #endif | |
172 | pv_mmu_ops.set_pud = kvm_set_pud; | |
173 | #if PAGETABLE_LEVELS == 4 | |
174 | pv_mmu_ops.set_pgd = kvm_set_pgd; | |
175 | #endif | |
176 | #endif | |
177 | pv_mmu_ops.flush_tlb_user = kvm_flush_tlb; | |
178 | pv_mmu_ops.release_pte = kvm_release_pt; | |
179 | pv_mmu_ops.release_pmd = kvm_release_pt; | |
180 | pv_mmu_ops.release_pud = kvm_release_pt; | |
181 | } | |
0cf1bfd2 MT |
182 | } |
183 | ||
184 | void __init kvm_guest_init(void) | |
185 | { | |
186 | if (!kvm_para_available()) | |
187 | return; | |
188 | ||
189 | paravirt_ops_setup(); | |
190 | } |