[mirror_ubuntu-artful-kernel.git] / arch / powerpc / kernel / kvm.c

/*
 * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
 *
 * Authors:
 *     Alexander Graf <agraf@suse.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/kvm_host.h>
#include <linux/init.h>
#include <linux/kvm_para.h>
#include <linux/slab.h>
#include <linux/of.h>

#include <asm/reg.h>
#include <asm/kvm_ppc.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
#include <asm/disassemble.h>

#define KVM_MAGIC_PAGE		(-4096L)
#define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)

#define KVM_INST_LWZ		0x80000000
#define KVM_INST_STW		0x90000000
#define KVM_INST_LD		0xe8000000
#define KVM_INST_STD		0xf8000000
#define KVM_INST_NOP		0x60000000
#define KVM_INST_B		0x48000000
#define KVM_INST_B_MASK		0x03ffffff
#define KVM_INST_B_MAX		0x01ffffff

#define KVM_MASK_RT		0x03e00000
#define KVM_INST_MFMSR		0x7c0000a6
#define KVM_INST_MFSPR_SPRG0	0x7c1042a6
#define KVM_INST_MFSPR_SPRG1	0x7c1142a6
#define KVM_INST_MFSPR_SPRG2	0x7c1242a6
#define KVM_INST_MFSPR_SPRG3	0x7c1342a6
#define KVM_INST_MFSPR_SRR0	0x7c1a02a6
#define KVM_INST_MFSPR_SRR1	0x7c1b02a6
#define KVM_INST_MFSPR_DAR	0x7c1302a6
#define KVM_INST_MFSPR_DSISR	0x7c1202a6

#define KVM_INST_MTSPR_SPRG0	0x7c1043a6
#define KVM_INST_MTSPR_SPRG1	0x7c1143a6
#define KVM_INST_MTSPR_SPRG2	0x7c1243a6
#define KVM_INST_MTSPR_SPRG3	0x7c1343a6
#define KVM_INST_MTSPR_SRR0	0x7c1a03a6
#define KVM_INST_MTSPR_SRR1	0x7c1b03a6
#define KVM_INST_MTSPR_DAR	0x7c1303a6
#define KVM_INST_MTSPR_DSISR	0x7c1203a6

static bool kvm_patching_worked = true;

static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
{
	*inst = new_inst;
	flush_icache_range((ulong)inst, (ulong)inst + 4);
}

static void kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
{
#ifdef CONFIG_64BIT
	kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
#else
	kvm_patch_ins(inst, KVM_INST_LWZ | rt | ((addr + 4) & 0x0000fffc));
#endif
}

static void kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
{
	kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000ffff));
}

static void kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
{
#ifdef CONFIG_64BIT
	kvm_patch_ins(inst, KVM_INST_STD | rt | (addr & 0x0000fffc));
#else
	kvm_patch_ins(inst, KVM_INST_STW | rt | ((addr + 4) & 0x0000fffc));
#endif
}

static void kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
{
	kvm_patch_ins(inst, KVM_INST_STW | rt | (addr & 0x0000fffc));
}

static void kvm_map_magic_page(void *data)
{
	kvm_hypercall2(KVM_HC_PPC_MAP_MAGIC_PAGE,
		       KVM_MAGIC_PAGE,  /* Physical Address */
		       KVM_MAGIC_PAGE); /* Effective Address */
}

static void kvm_check_ins(u32 *inst)
{
	u32 _inst = *inst;
	u32 inst_no_rt = _inst & ~KVM_MASK_RT;
	u32 inst_rt = _inst & KVM_MASK_RT;

	switch (inst_no_rt) {
	/* Loads */
	case KVM_INST_MFMSR:
		kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
		break;
	case KVM_INST_MFSPR_SPRG0:
		kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
		break;
	case KVM_INST_MFSPR_SPRG1:
		kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
		break;
	case KVM_INST_MFSPR_SPRG2:
		kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
		break;
	case KVM_INST_MFSPR_SPRG3:
		kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
		break;
	case KVM_INST_MFSPR_SRR0:
		kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
		break;
	case KVM_INST_MFSPR_SRR1:
		kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
		break;
	case KVM_INST_MFSPR_DAR:
		kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
		break;
	case KVM_INST_MFSPR_DSISR:
		kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
		break;

	/* Stores */
	case KVM_INST_MTSPR_SPRG0:
		kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
		break;
	case KVM_INST_MTSPR_SPRG1:
		kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
		break;
	case KVM_INST_MTSPR_SPRG2:
		kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
		break;
	case KVM_INST_MTSPR_SPRG3:
		kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
		break;
	case KVM_INST_MTSPR_SRR0:
		kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
		break;
	case KVM_INST_MTSPR_SRR1:
		kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
		break;
	case KVM_INST_MTSPR_DAR:
		kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
		break;
	case KVM_INST_MTSPR_DSISR:
		kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
		break;
	}

	switch (_inst) {
	}
}

static void kvm_use_magic_page(void)
{
	u32 *p;
	u32 *start, *end;
	u32 tmp;

	/* Tell the host to map the magic page to -4096 on all CPUs */
	on_each_cpu(kvm_map_magic_page, NULL, 1);

	/* Quick self-test to see if the mapping works */
	if (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
		kvm_patching_worked = false;
		return;
	}

	/* Now loop through all code and find instructions */
	start = (void*)_stext;
	end = (void*)_etext;

	for (p = start; p < end; p++)
		kvm_check_ins(p);

	printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
			 kvm_patching_worked ? "worked" : "failed");
}

unsigned long kvm_hypercall(unsigned long *in,
			    unsigned long *out,
			    unsigned long nr)
{
	unsigned long register r0 asm("r0");
	unsigned long register r3 asm("r3") = in[0];
	unsigned long register r4 asm("r4") = in[1];
	unsigned long register r5 asm("r5") = in[2];
	unsigned long register r6 asm("r6") = in[3];
	unsigned long register r7 asm("r7") = in[4];
	unsigned long register r8 asm("r8") = in[5];
	unsigned long register r9 asm("r9") = in[6];
	unsigned long register r10 asm("r10") = in[7];
	unsigned long register r11 asm("r11") = nr;
	unsigned long register r12 asm("r12");

	asm volatile("bl	kvm_hypercall_start"
		     : "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
		       "=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
		       "=r"(r12)
		     : "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
		       "r"(r9), "r"(r10), "r"(r11)
		     : "memory", "cc", "xer", "ctr", "lr");

	out[0] = r4;
	out[1] = r5;
	out[2] = r6;
	out[3] = r7;
	out[4] = r8;
	out[5] = r9;
	out[6] = r10;
	out[7] = r11;

	return r3;
}
EXPORT_SYMBOL_GPL(kvm_hypercall);

static int kvm_para_setup(void)
{
	extern u32 kvm_hypercall_start;
	struct device_node *hyper_node;
	u32 *insts;
	int len, i;

	hyper_node = of_find_node_by_path("/hypervisor");
	if (!hyper_node)
		return -1;

	insts = (u32*)of_get_property(hyper_node, "hcall-instructions", &len);
	if (len % 4)
		return -1;
	if (len > (4 * 4))
		return -1;

	for (i = 0; i < (len / 4); i++)
		kvm_patch_ins(&(&kvm_hypercall_start)[i], insts[i]);

	return 0;
}

static int __init kvm_guest_init(void)
{
	if (!kvm_para_available())
		return 0;

	if (kvm_para_setup())
		return 0;

	if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
		kvm_use_magic_page();

	return 0;
}

postcore_initcall(kvm_guest_init);
Commit	Line	Data
2a342ed5 AG	1	/*
	2	* Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
	3	*
	4	* Authors:
	5	* Alexander Graf <agraf@suse.de>
	6	*
	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.
	10	*
	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.
	15	*
	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.
	19	*/
	20
	21	#include <linux/kvm_host.h>
	22	#include <linux/init.h>
	23	#include <linux/kvm_para.h>
	24	#include <linux/slab.h>
	25	#include <linux/of.h>
	26
	27	#include <asm/reg.h>
	28	#include <asm/kvm_ppc.h>
	29	#include <asm/sections.h>
	30	#include <asm/cacheflush.h>
	31	#include <asm/disassemble.h>
	32
d17051cb AG	33	#define KVM_MAGIC_PAGE (-4096L)
	34	#define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
	35
d1293c92 AG	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
	44
73a18109	45	#define KVM_MASK_RT 0x03e00000
d1293c92 AG	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
	55
	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
73a18109 AG	64
	65	static bool kvm_patching_worked = true;
	66
	67	static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
	68	{
	69	*inst = new_inst;
	70	flush_icache_range((ulong)inst, (ulong)inst + 4);
	71	}
	72
d1293c92 AG	73	static void kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
	74	{
	75	#ifdef CONFIG_64BIT
	76	kvm_patch_ins(inst, KVM_INST_LD \| rt \| (addr & 0x0000fffc));
	77	#else
	78	kvm_patch_ins(inst, KVM_INST_LWZ \| rt \| ((addr + 4) & 0x0000fffc));
	79	#endif
	80	}
	81
	82	static void kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
	83	{
	84	kvm_patch_ins(inst, KVM_INST_LWZ \| rt \| (addr & 0x0000ffff));
	85	}
	86
	87	static void kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
	88	{
	89	#ifdef CONFIG_64BIT
	90	kvm_patch_ins(inst, KVM_INST_STD \| rt \| (addr & 0x0000fffc));
	91	#else
	92	kvm_patch_ins(inst, KVM_INST_STW \| rt \| ((addr + 4) & 0x0000fffc));
	93	#endif
	94	}
	95
	96	static void kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
	97	{
	98	kvm_patch_ins(inst, KVM_INST_STW \| rt \| (addr & 0x0000fffc));
	99	}
	100
73a18109 AG	101	static void kvm_map_magic_page(void *data)
	102	{
	103	kvm_hypercall2(KVM_HC_PPC_MAP_MAGIC_PAGE,
	104	KVM_MAGIC_PAGE, /* Physical Address */
	105	KVM_MAGIC_PAGE); /* Effective Address */
	106	}
	107
	108	static void kvm_check_ins(u32 *inst)
	109	{
	110	u32 _inst = *inst;
	111	u32 inst_no_rt = _inst & ~KVM_MASK_RT;
	112	u32 inst_rt = _inst & KVM_MASK_RT;
	113
	114	switch (inst_no_rt) {
d1293c92 AG	115	/* Loads */
	116	case KVM_INST_MFMSR:
	117	kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
	118	break;
	119	case KVM_INST_MFSPR_SPRG0:
	120	kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
	121	break;
	122	case KVM_INST_MFSPR_SPRG1:
	123	kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
	124	break;
	125	case KVM_INST_MFSPR_SPRG2:
	126	kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
	127	break;
	128	case KVM_INST_MFSPR_SPRG3:
	129	kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
	130	break;
	131	case KVM_INST_MFSPR_SRR0:
	132	kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
	133	break;
	134	case KVM_INST_MFSPR_SRR1:
	135	kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
	136	break;
	137	case KVM_INST_MFSPR_DAR:
	138	kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
	139	break;
	140	case KVM_INST_MFSPR_DSISR:
	141	kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
	142	break;
	143
	144	/* Stores */
	145	case KVM_INST_MTSPR_SPRG0:
	146	kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
	147	break;
	148	case KVM_INST_MTSPR_SPRG1:
	149	kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
	150	break;
	151	case KVM_INST_MTSPR_SPRG2:
	152	kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
	153	break;
	154	case KVM_INST_MTSPR_SPRG3:
	155	kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
	156	break;
	157	case KVM_INST_MTSPR_SRR0:
	158	kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
	159	break;
	160	case KVM_INST_MTSPR_SRR1:
	161	kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
	162	break;
	163	case KVM_INST_MTSPR_DAR:
	164	kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
	165	break;
	166	case KVM_INST_MTSPR_DSISR:
	167	kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
	168	break;
73a18109 AG	169	}
	170
	171	switch (_inst) {
	172	}
	173	}
	174
	175	static void kvm_use_magic_page(void)
	176	{
	177	u32 *p;
	178	u32 start, end;
	179	u32 tmp;
	180
	181	/* Tell the host to map the magic page to -4096 on all CPUs */
	182	on_each_cpu(kvm_map_magic_page, NULL, 1);
	183
	184	/* Quick self-test to see if the mapping works */
	185	if (__get_user(tmp, (u32*)KVM_MAGIC_PAGE)) {
	186	kvm_patching_worked = false;
	187	return;
	188	}
	189
	190	/* Now loop through all code and find instructions */
	191	start = (void*)_stext;
	192	end = (void*)_etext;
	193
	194	for (p = start; p < end; p++)
	195	kvm_check_ins(p);
	196
	197	printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
	198	kvm_patching_worked ? "worked" : "failed");
	199	}
	200
2a342ed5 AG	201	unsigned long kvm_hypercall(unsigned long *in,
	202	unsigned long *out,
	203	unsigned long nr)
	204	{
	205	unsigned long register r0 asm("r0");
	206	unsigned long register r3 asm("r3") = in[0];
	207	unsigned long register r4 asm("r4") = in[1];
	208	unsigned long register r5 asm("r5") = in[2];
	209	unsigned long register r6 asm("r6") = in[3];
	210	unsigned long register r7 asm("r7") = in[4];
	211	unsigned long register r8 asm("r8") = in[5];
	212	unsigned long register r9 asm("r9") = in[6];
	213	unsigned long register r10 asm("r10") = in[7];
	214	unsigned long register r11 asm("r11") = nr;
	215	unsigned long register r12 asm("r12");
	216
	217	asm volatile("bl kvm_hypercall_start"
	218	: "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6),
	219	"=r"(r7), "=r"(r8), "=r"(r9), "=r"(r10), "=r"(r11),
	220	"=r"(r12)
	221	: "r"(r3), "r"(r4), "r"(r5), "r"(r6), "r"(r7), "r"(r8),
	222	"r"(r9), "r"(r10), "r"(r11)
	223	: "memory", "cc", "xer", "ctr", "lr");
	224
	225	out[0] = r4;
	226	out[1] = r5;
	227	out[2] = r6;
	228	out[3] = r7;
	229	out[4] = r8;
	230	out[5] = r9;
	231	out[6] = r10;
	232	out[7] = r11;
	233
	234	return r3;
	235	}
	236	EXPORT_SYMBOL_GPL(kvm_hypercall);
73a18109 AG	237
	238	static int kvm_para_setup(void)
	239	{
	240	extern u32 kvm_hypercall_start;
	241	struct device_node *hyper_node;
	242	u32 *insts;
	243	int len, i;
	244
	245	hyper_node = of_find_node_by_path("/hypervisor");
	246	if (!hyper_node)
	247	return -1;
	248
	249	insts = (u32*)of_get_property(hyper_node, "hcall-instructions", &len);
	250	if (len % 4)
	251	return -1;
	252	if (len > (4 * 4))
	253	return -1;
	254
	255	for (i = 0; i < (len / 4); i++)
	256	kvm_patch_ins(&(&kvm_hypercall_start)[i], insts[i]);
	257
	258	return 0;
	259	}
	260
	261	static int __init kvm_guest_init(void)
	262	{
	263	if (!kvm_para_available())
	264	return 0;
	265
	266	if (kvm_para_setup())
	267	return 0;
	268
	269	if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
	270	kvm_use_magic_page();
	271
	272	return 0;
	273	}
	274
	275	postcore_initcall(kvm_guest_init);