aboutsummaryrefslogtreecommitdiff
path: root/arch/s390/kvm/pv.c
blob: eb99e2f95ebed41679db4dc7ca172f4d76696fae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
// SPDX-License-Identifier: GPL-2.0
/*
 * Hosting Protected Virtual Machines
 *
 * Copyright IBM Corp. 2019, 2020
 *    Author(s): Janosch Frank <frankja@linux.ibm.com>
 */
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/pagemap.h>
#include <linux/sched/signal.h>
#include <asm/gmap.h>
#include <asm/uv.h>
#include <asm/mman.h>
#include "kvm-s390.h"

int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
{
	int cc = 0;

	if (kvm_s390_pv_cpu_get_handle(vcpu)) {
		cc = uv_cmd_nodata(kvm_s390_pv_cpu_get_handle(vcpu),
				   UVC_CMD_DESTROY_SEC_CPU, rc, rrc);

		KVM_UV_EVENT(vcpu->kvm, 3,
			     "PROTVIRT DESTROY VCPU %d: rc %x rrc %x",
			     vcpu->vcpu_id, *rc, *rrc);
		WARN_ONCE(cc, "protvirt destroy cpu failed rc %x rrc %x",
			  *rc, *rrc);
	}
	/* Intended memory leak for something that should never happen. */
	if (!cc)
		free_pages(vcpu->arch.pv.stor_base,
			   get_order(uv_info.guest_cpu_stor_len));

	free_page(sida_origin(vcpu->arch.sie_block));
	vcpu->arch.sie_block->pv_handle_cpu = 0;
	vcpu->arch.sie_block->pv_handle_config = 0;
	memset(&vcpu->arch.pv, 0, sizeof(vcpu->arch.pv));
	vcpu->arch.sie_block->sdf = 0;
	/*
	 * The sidad field (for sdf == 2) is now the gbea field (for sdf == 0).
	 * Use the reset value of gbea to avoid leaking the kernel pointer of
	 * the just freed sida.
	 */
	vcpu->arch.sie_block->gbea = 1;
	kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);

	return cc ? EIO : 0;
}

int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
{
	struct uv_cb_csc uvcb = {
		.header.cmd = UVC_CMD_CREATE_SEC_CPU,
		.header.len = sizeof(uvcb),
	};
	int cc;

	if (kvm_s390_pv_cpu_get_handle(vcpu))
		return -EINVAL;

	vcpu->arch.pv.stor_base = __get_free_pages(GFP_KERNEL,
						   get_order(uv_info.guest_cpu_stor_len));
	if (!vcpu->arch.pv.stor_base)
		return -ENOMEM;

	/* Input */
	uvcb.guest_handle = kvm_s390_pv_get_handle(vcpu->kvm);
	uvcb.num = vcpu->arch.sie_block->icpua;
	uvcb.state_origin = (u64)vcpu->arch.sie_block;
	uvcb.stor_origin = (u64)vcpu->arch.pv.stor_base;

	/* Alloc Secure Instruction Data Area Designation */
	vcpu->arch.sie_block->sidad = __get_free_page(GFP_KERNEL | __GFP_ZERO);
	if (!vcpu->arch.sie_block->sidad) {
		free_pages(vcpu->arch.pv.stor_base,
			   get_order(uv_info.guest_cpu_stor_len));
		return -ENOMEM;
	}

	cc = uv_call(0, (u64)&uvcb);
	*rc = uvcb.header.rc;
	*rrc = uvcb.header.rrc;
	KVM_UV_EVENT(vcpu->kvm, 3,
		     "PROTVIRT CREATE VCPU: cpu %d handle %llx rc %x rrc %x",
		     vcpu->vcpu_id, uvcb.cpu_handle, uvcb.header.rc,
		     uvcb.header.rrc);

	if (cc) {
		u16 dummy;

		kvm_s390_pv_destroy_cpu(vcpu, &dummy, &dummy);
		return -EIO;
	}

	/* Output */
	vcpu->arch.pv.handle = uvcb.cpu_handle;
	vcpu->arch.sie_block->pv_handle_cpu = uvcb.cpu_handle;
	vcpu->arch.sie_block->pv_handle_config = kvm_s390_pv_get_handle(vcpu->kvm);
	vcpu->arch.sie_block->sdf = 2;
	kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
	return 0;
}

/* only free resources when the destroy was successful */
static void kvm_s390_pv_dealloc_vm(struct kvm *kvm)
{
	vfree(kvm->arch.pv.stor_var);
	free_pages(kvm->arch.pv.stor_base,
		   get_order(uv_info.guest_base_stor_len));
	memset(&kvm->arch.pv, 0, sizeof(kvm->arch.pv));
}

static int kvm_s390_pv_alloc_vm(struct kvm *kvm)
{
	unsigned long base = uv_info.guest_base_stor_len;
	unsigned long virt = uv_info.guest_virt_var_stor_len;
	unsigned long npages = 0, vlen = 0;
	struct kvm_memory_slot *memslot;

	kvm->arch.pv.stor_var = NULL;
	kvm->arch.pv.stor_base = __get_free_pages(GFP_KERNEL, get_order(base));
	if (!kvm->arch.pv.stor_base)
		return -ENOMEM;

	/*
	 * Calculate current guest storage for allocation of the
	 * variable storage, which is based on the length in MB.
	 *
	 * Slots are sorted by GFN
	 */
	mutex_lock(&kvm->slots_lock);
	memslot = kvm_memslots(kvm)->memslots;
	npages = memslot->base_gfn + memslot->npages;
	mutex_unlock(&kvm->slots_lock);

	kvm->arch.pv.guest_len = npages * PAGE_SIZE;

	/* Allocate variable storage */
	vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE);
	vlen += uv_info.guest_virt_base_stor_len;
	kvm->arch.pv.stor_var = vzalloc(vlen);
	if (!kvm->arch.pv.stor_var)
		goto out_err;
	return 0;

out_err:
	kvm_s390_pv_dealloc_vm(kvm);
	return -ENOMEM;
}

/* this should not fail, but if it does, we must not free the donated memory */
int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
{
	int cc;

	/* make all pages accessible before destroying the guest */
	s390_reset_acc(kvm->mm);

	cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm),
			   UVC_CMD_DESTROY_SEC_CONF, rc, rrc);
	WRITE_ONCE(kvm->arch.gmap->guest_handle, 0);
	atomic_set(&kvm->mm->context.is_protected, 0);
	KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM: rc %x rrc %x", *rc, *rrc);
	WARN_ONCE(cc, "protvirt destroy vm failed rc %x rrc %x", *rc, *rrc);
	/* Inteded memory leak on "impossible" error */
	if (!cc)
		kvm_s390_pv_dealloc_vm(kvm);
	return cc ? -EIO : 0;
}

int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
{
	struct uv_cb_cgc uvcb = {
		.header.cmd = UVC_CMD_CREATE_SEC_CONF,
		.header.len = sizeof(uvcb)
	};
	int cc, ret;
	u16 dummy;

	ret = kvm_s390_pv_alloc_vm(kvm);
	if (ret)
		return ret;

	/* Inputs */
	uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */
	uvcb.guest_stor_len = kvm->arch.pv.guest_len;
	uvcb.guest_asce = kvm->arch.gmap->asce;
	uvcb.guest_sca = (unsigned long)kvm->arch.sca;
	uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base;
	uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;

	cc = uv_call(0, (u64)&uvcb);
	*rc = uvcb.header.rc;
	*rrc = uvcb.header.rrc;
	KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x",
		     uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc);

	/* Outputs */
	kvm->arch.pv.handle = uvcb.guest_handle;

	if (cc) {
		if (uvcb.header.rc & UVC_RC_NEED_DESTROY)
			kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy);
		else
			kvm_s390_pv_dealloc_vm(kvm);
		return -EIO;
	}
	kvm->arch.gmap->guest_handle = uvcb.guest_handle;
	atomic_set(&kvm->mm->context.is_protected, 1);
	return 0;
}

int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
			      u16 *rrc)
{
	struct uv_cb_ssc uvcb = {
		.header.cmd = UVC_CMD_SET_SEC_CONF_PARAMS,
		.header.len = sizeof(uvcb),
		.sec_header_origin = (u64)hdr,
		.sec_header_len = length,
		.guest_handle = kvm_s390_pv_get_handle(kvm),
	};
	int cc = uv_call(0, (u64)&uvcb);

	*rc = uvcb.header.rc;
	*rrc = uvcb.header.rrc;
	KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x",
		     *rc, *rrc);
	return cc ? -EINVAL : 0;
}

static int unpack_one(struct kvm *kvm, unsigned long addr, u64 tweak,
		      u64 offset, u16 *rc, u16 *rrc)
{
	struct uv_cb_unp uvcb = {
		.header.cmd = UVC_CMD_UNPACK_IMG,
		.header.len = sizeof(uvcb),
		.guest_handle = kvm_s390_pv_get_handle(kvm),
		.gaddr = addr,
		.tweak[0] = tweak,
		.tweak[1] = offset,
	};
	int ret = gmap_make_secure(kvm->arch.gmap, addr, &uvcb);

	*rc = uvcb.header.rc;
	*rrc = uvcb.header.rrc;

	if (ret && ret != -EAGAIN)
		KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: failed addr %llx with rc %x rrc %x",
			     uvcb.gaddr, *rc, *rrc);
	return ret;
}

int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
		       unsigned long tweak, u16 *rc, u16 *rrc)
{
	u64 offset = 0;
	int ret = 0;

	if (addr & ~PAGE_MASK || !size || size & ~PAGE_MASK)
		return -EINVAL;

	KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: start addr %lx size %lx",
		     addr, size);

	while (offset < size) {
		ret = unpack_one(kvm, addr, tweak, offset, rc, rrc);
		if (ret == -EAGAIN) {
			cond_resched();
			if (fatal_signal_pending(current))
				break;
			continue;
		}
		if (ret)
			break;
		addr += PAGE_SIZE;
		offset += PAGE_SIZE;
	}
	if (!ret)
		KVM_UV_EVENT(kvm, 3, "%s", "PROTVIRT VM UNPACK: successful");
	return ret;
}

int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
{
	struct uv_cb_cpu_set_state uvcb = {
		.header.cmd	= UVC_CMD_CPU_SET_STATE,
		.header.len	= sizeof(uvcb),
		.cpu_handle	= kvm_s390_pv_cpu_get_handle(vcpu),
		.state		= state,
	};
	int cc;

	cc = uv_call(0, (u64)&uvcb);
	KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT SET CPU %d STATE %d rc %x rrc %x",
		     vcpu->vcpu_id, state, uvcb.header.rc, uvcb.header.rrc);
	if (cc)
		return -EINVAL;
	return 0;
}