acpi_pad: build only on X86
[linux-2.6/linux-acpi-2.6.git] / arch / x86 / kernel / kvm.c
blobc664d515f613576c7ccd1168afcc47bf897a0855
1 /*
2 * KVM paravirt_ops implementation
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.
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.
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.
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>
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>
28 #include <linux/highmem.h>
29 #include <linux/hardirq.h>
30 #include <asm/timer.h>
32 #define MMU_QUEUE_SIZE 1024
34 struct kvm_para_state {
35 u8 mmu_queue[MMU_QUEUE_SIZE];
36 int mmu_queue_len;
37 enum paravirt_lazy_mode mode;
40 static DEFINE_PER_CPU(struct kvm_para_state, para_state);
42 static struct kvm_para_state *kvm_para_state(void)
44 return &per_cpu(para_state, raw_smp_processor_id());
48 * No need for any "IO delay" on KVM
50 static void kvm_io_delay(void)
54 static void kvm_mmu_op(void *buffer, unsigned len)
56 int r;
57 unsigned long a1, a2;
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);
68 static void mmu_queue_flush(struct kvm_para_state *state)
70 if (state->mmu_queue_len) {
71 kvm_mmu_op(state->mmu_queue, state->mmu_queue_len);
72 state->mmu_queue_len = 0;
76 static void kvm_deferred_mmu_op(void *buffer, int len)
78 struct kvm_para_state *state = kvm_para_state();
80 if (state->mode != PARAVIRT_LAZY_MMU) {
81 kvm_mmu_op(buffer, len);
82 return;
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;
90 static void kvm_mmu_write(void *dest, u64 val)
92 __u64 pte_phys;
93 struct kvm_mmu_op_write_pte wpte;
95 #ifdef CONFIG_HIGHPTE
96 struct page *page;
97 unsigned long dst = (unsigned long) dest;
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;
110 kvm_deferred_mmu_op(&wpte, sizeof wpte);
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.
119 static void kvm_set_pte(pte_t *ptep, pte_t pte)
121 kvm_mmu_write(ptep, pte_val(pte));
124 static void kvm_set_pte_at(struct mm_struct *mm, unsigned long addr,
125 pte_t *ptep, pte_t pte)
127 kvm_mmu_write(ptep, pte_val(pte));
130 static void kvm_set_pmd(pmd_t *pmdp, pmd_t pmd)
132 kvm_mmu_write(pmdp, pmd_val(pmd));
135 #if PAGETABLE_LEVELS >= 3
136 #ifdef CONFIG_X86_PAE
137 static void kvm_set_pte_atomic(pte_t *ptep, pte_t pte)
139 kvm_mmu_write(ptep, pte_val(pte));
142 static void kvm_pte_clear(struct mm_struct *mm,
143 unsigned long addr, pte_t *ptep)
145 kvm_mmu_write(ptep, 0);
148 static void kvm_pmd_clear(pmd_t *pmdp)
150 kvm_mmu_write(pmdp, 0);
152 #endif
154 static void kvm_set_pud(pud_t *pudp, pud_t pud)
156 kvm_mmu_write(pudp, pud_val(pud));
159 #if PAGETABLE_LEVELS == 4
160 static void kvm_set_pgd(pgd_t *pgdp, pgd_t pgd)
162 kvm_mmu_write(pgdp, pgd_val(pgd));
164 #endif
165 #endif /* PAGETABLE_LEVELS >= 3 */
167 static void kvm_flush_tlb(void)
169 struct kvm_mmu_op_flush_tlb ftlb = {
170 .header.op = KVM_MMU_OP_FLUSH_TLB,
173 kvm_deferred_mmu_op(&ftlb, sizeof ftlb);
176 static void kvm_release_pt(unsigned long pfn)
178 struct kvm_mmu_op_release_pt rpt = {
179 .header.op = KVM_MMU_OP_RELEASE_PT,
180 .pt_phys = (u64)pfn << PAGE_SHIFT,
183 kvm_mmu_op(&rpt, sizeof rpt);
186 static void kvm_enter_lazy_mmu(void)
188 struct kvm_para_state *state = kvm_para_state();
190 paravirt_enter_lazy_mmu();
191 state->mode = paravirt_get_lazy_mode();
194 static void kvm_leave_lazy_mmu(void)
196 struct kvm_para_state *state = kvm_para_state();
198 mmu_queue_flush(state);
199 paravirt_leave_lazy_mmu();
200 state->mode = paravirt_get_lazy_mode();
203 static void __init paravirt_ops_setup(void)
205 pv_info.name = "KVM";
206 pv_info.paravirt_enabled = 1;
208 if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY))
209 pv_cpu_ops.io_delay = kvm_io_delay;
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;
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;
231 pv_mmu_ops.lazy_mode.enter = kvm_enter_lazy_mmu;
232 pv_mmu_ops.lazy_mode.leave = kvm_leave_lazy_mmu;
234 #ifdef CONFIG_X86_IO_APIC
235 no_timer_check = 1;
236 #endif
239 void __init kvm_guest_init(void)
241 if (!kvm_para_available())
242 return;
244 paravirt_ops_setup();