2 * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
5 * Alexander Graf <agraf@suse.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License, version 2, as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 #include <linux/kvm_host.h>
22 #include <linux/init.h>
23 #include <linux/kvm_para.h>
24 #include <linux/slab.h>
28 #include <asm/kvm_ppc.h>
29 #include <asm/sections.h>
30 #include <asm/cacheflush.h>
31 #include <asm/disassemble.h>
33 #define KVM_MAGIC_PAGE (-4096L)
34 #define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
36 #define KVM_INST_LWZ 0x80000000
37 #define KVM_INST_STW 0x90000000
38 #define KVM_INST_LD 0xe8000000
39 #define KVM_INST_STD 0xf8000000
40 #define KVM_INST_NOP 0x60000000
41 #define KVM_INST_B 0x48000000
42 #define KVM_INST_B_MASK 0x03ffffff
43 #define KVM_INST_B_MAX 0x01ffffff
45 #define KVM_MASK_RT 0x03e00000
46 #define KVM_INST_MFMSR 0x7c0000a6
47 #define KVM_INST_MFSPR_SPRG0 0x7c1042a6
48 #define KVM_INST_MFSPR_SPRG1 0x7c1142a6
49 #define KVM_INST_MFSPR_SPRG2 0x7c1242a6
50 #define KVM_INST_MFSPR_SPRG3 0x7c1342a6
51 #define KVM_INST_MFSPR_SRR0 0x7c1a02a6
52 #define KVM_INST_MFSPR_SRR1 0x7c1b02a6
53 #define KVM_INST_MFSPR_DAR 0x7c1302a6
54 #define KVM_INST_MFSPR_DSISR 0x7c1202a6
56 #define KVM_INST_MTSPR_SPRG0 0x7c1043a6
57 #define KVM_INST_MTSPR_SPRG1 0x7c1143a6
58 #define KVM_INST_MTSPR_SPRG2 0x7c1243a6
59 #define KVM_INST_MTSPR_SPRG3 0x7c1343a6
60 #define KVM_INST_MTSPR_SRR0 0x7c1a03a6
61 #define KVM_INST_MTSPR_SRR1 0x7c1b03a6
62 #define KVM_INST_MTSPR_DAR 0x7c1303a6
63 #define KVM_INST_MTSPR_DSISR 0x7c1203a6
65 #define KVM_INST_TLBSYNC 0x7c00046c
67 static bool kvm_patching_worked = true;
68 static char kvm_tmp[1024 * 1024];
69 static int kvm_tmp_index;
71 static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
74 flush_icache_range((ulong)inst, (ulong)inst + 4);
77 static void kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
80 kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
82 kvm_patch_ins(inst, KVM_INST_LWZ | rt | ((addr + 4) & 0x0000fffc));
86 static void kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
88 kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000ffff));
91 static void kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
94 kvm_patch_ins(inst, KVM_INST_STD | rt | (addr & 0x0000fffc));
96 kvm_patch_ins(inst, KVM_INST_STW | rt | ((addr + 4) & 0x0000fffc));
100 static void kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
102 kvm_patch_ins(inst, KVM_INST_STW | rt | (addr & 0x0000fffc));
105 static void kvm_patch_ins_nop(u32 *inst)
107 kvm_patch_ins(inst, KVM_INST_NOP);
110 static void kvm_patch_ins_b(u32 *inst, int addr)
112 #ifdef CONFIG_RELOCATABLE
113 /* On relocatable kernels interrupts handlers and our code
114 can be in different regions, so we don't patch them */
116 extern u32 __end_interrupts;
117 if ((ulong)inst < (ulong)&__end_interrupts)
121 kvm_patch_ins(inst, KVM_INST_B | (addr & KVM_INST_B_MASK));
124 static u32 *kvm_alloc(int len)
128 if ((kvm_tmp_index + len) > ARRAY_SIZE(kvm_tmp)) {
129 printk(KERN_ERR "KVM: No more space (%d + %d)\n",
131 kvm_patching_worked = false;
135 p = (void*)&kvm_tmp[kvm_tmp_index];
136 kvm_tmp_index += len;
141 static void kvm_map_magic_page(void *data)
143 kvm_hypercall2(KVM_HC_PPC_MAP_MAGIC_PAGE,
144 KVM_MAGIC_PAGE, /* Physical Address */
145 KVM_MAGIC_PAGE); /* Effective Address */
148 static void kvm_check_ins(u32 *inst)
151 u32 inst_no_rt = _inst & ~KVM_MASK_RT;
152 u32 inst_rt = _inst & KVM_MASK_RT;
154 switch (inst_no_rt) {
157 kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
159 case KVM_INST_MFSPR_SPRG0:
160 kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
162 case KVM_INST_MFSPR_SPRG1:
163 kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
165 case KVM_INST_MFSPR_SPRG2:
166 kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
168 case KVM_INST_MFSPR_SPRG3:
169 kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
171 case KVM_INST_MFSPR_SRR0:
172 kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
174 case KVM_INST_MFSPR_SRR1:
175 kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
177 case KVM_INST_MFSPR_DAR:
178 kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
180 case KVM_INST_MFSPR_DSISR:
181 kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
185 case KVM_INST_MTSPR_SPRG0:
186 kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
188 case KVM_INST_MTSPR_SPRG1:
189 kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
191 case KVM_INST_MTSPR_SPRG2:
192 kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
194 case KVM_INST_MTSPR_SPRG3:
195 kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
197 case KVM_INST_MTSPR_SRR0:
198 kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
200 case KVM_INST_MTSPR_SRR1:
201 kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
203 case KVM_INST_MTSPR_DAR:
204 kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
206 case KVM_INST_MTSPR_DSISR:
207 kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
211 case KVM_INST_TLBSYNC:
212 kvm_patch_ins_nop(inst);
220 static void kvm_use_magic_page(void)
226 /* Tell the host to map the magic page to -4096 on all CPUs */
227 on_each_cpu(kvm_map_magic_page, NULL, 1);
229 /* Quick self-test to see if the mapping works */
230 if (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
231 kvm_patching_worked = false;
235 /* Now loop through all code and find instructions */
236 start = (void*)_stext;
239 for (p = start; p < end; p++)
242 printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
243 kvm_patching_worked ? "worked" : "failed");
246 unsigned long kvm_hypercall(unsigned long *in,
250 unsigned long register r0 asm("r0");
251 unsigned long register r3 asm("r3") = in[0];
252 unsigned long register r4 asm("r4") = in[1];
253 unsigned long register r5 asm("r5") = in[2];
254 unsigned long register r6 asm("r6") = in[3];
255 unsigned long register r7 asm("r7") = in[4];
256 unsigned long register r8 asm("r8") = in[5];
257 unsigned long register r9 asm("r9") = in[6];
258 unsigned long register r10 asm("r10") = in[7];
259 unsigned long register r11 asm("r11") = nr;
260 unsigned long register r12 asm("r12");
262 asm volatile("bl kvm_hypercall_start"
263 : "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
264 "=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
266 : "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
267 "r"(r9), "r"(r10), "r"(r11)
268 : "memory", "cc", "xer", "ctr", "lr");
281 EXPORT_SYMBOL_GPL(kvm_hypercall);
283 static int kvm_para_setup(void)
285 extern u32 kvm_hypercall_start;
286 struct device_node *hyper_node;
290 hyper_node = of_find_node_by_path("/hypervisor");
294 insts = (u32*)of_get_property(hyper_node, "hcall-instructions", &len);
300 for (i = 0; i < (len / 4); i++)
301 kvm_patch_ins(&(&kvm_hypercall_start)[i], insts[i]);
306 static __init void kvm_free_tmp(void)
308 unsigned long start, end;
310 start = (ulong)&kvm_tmp[kvm_tmp_index + (PAGE_SIZE - 1)] & PAGE_MASK;
311 end = (ulong)&kvm_tmp[ARRAY_SIZE(kvm_tmp)] & PAGE_MASK;
313 /* Free the tmp space we don't need */
314 for (; start < end; start += PAGE_SIZE) {
315 ClearPageReserved(virt_to_page(start));
316 init_page_count(virt_to_page(start));
322 static int __init kvm_guest_init(void)
324 if (!kvm_para_available())
327 if (kvm_para_setup())
330 if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
331 kvm_use_magic_page();
339 postcore_initcall(kvm_guest_init);