1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Hosting Protected Virtual Machines
4 *
5 * Copyright IBM Corp. 2019, 2020
6 * Author(s): Janosch Frank <frankja@linux.ibm.com>
7 */
8 #include <linux/kvm.h>
9 #include <linux/kvm_host.h>
10 #include <linux/pagemap.h>
11 #include <linux/sched/signal.h>
12 #include <asm/gmap.h>
13 #include <asm/uv.h>
14 #include <asm/mman.h>
15 #include "kvm-s390.h"
16
kvm_s390_pv_destroy_cpu(struct kvm_vcpu * vcpu,u16 * rc,u16 * rrc)17 int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
18 {
19 int cc;
20
21 if (!kvm_s390_pv_cpu_get_handle(vcpu))
22 return 0;
23
24 cc = uv_cmd_nodata(kvm_s390_pv_cpu_get_handle(vcpu), UVC_CMD_DESTROY_SEC_CPU, rc, rrc);
25
26 KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT DESTROY VCPU %d: rc %x rrc %x",
27 vcpu->vcpu_id, *rc, *rrc);
28 WARN_ONCE(cc, "protvirt destroy cpu failed rc %x rrc %x", *rc, *rrc);
29
30 /* Intended memory leak for something that should never happen. */
31 if (!cc)
32 free_pages(vcpu->arch.pv.stor_base,
33 get_order(uv_info.guest_cpu_stor_len));
34
35 free_page(sida_origin(vcpu->arch.sie_block));
36 vcpu->arch.sie_block->pv_handle_cpu = 0;
37 vcpu->arch.sie_block->pv_handle_config = 0;
38 memset(&vcpu->arch.pv, 0, sizeof(vcpu->arch.pv));
39 vcpu->arch.sie_block->sdf = 0;
40 /*
41 * The sidad field (for sdf == 2) is now the gbea field (for sdf == 0).
42 * Use the reset value of gbea to avoid leaking the kernel pointer of
43 * the just freed sida.
44 */
45 vcpu->arch.sie_block->gbea = 1;
46 kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
47
48 return cc ? EIO : 0;
49 }
50
kvm_s390_pv_create_cpu(struct kvm_vcpu * vcpu,u16 * rc,u16 * rrc)51 int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
52 {
53 struct uv_cb_csc uvcb = {
54 .header.cmd = UVC_CMD_CREATE_SEC_CPU,
55 .header.len = sizeof(uvcb),
56 };
57 int cc;
58
59 if (kvm_s390_pv_cpu_get_handle(vcpu))
60 return -EINVAL;
61
62 vcpu->arch.pv.stor_base = __get_free_pages(GFP_KERNEL,
63 get_order(uv_info.guest_cpu_stor_len));
64 if (!vcpu->arch.pv.stor_base)
65 return -ENOMEM;
66
67 /* Input */
68 uvcb.guest_handle = kvm_s390_pv_get_handle(vcpu->kvm);
69 uvcb.num = vcpu->arch.sie_block->icpua;
70 uvcb.state_origin = (u64)vcpu->arch.sie_block;
71 uvcb.stor_origin = (u64)vcpu->arch.pv.stor_base;
72
73 /* Alloc Secure Instruction Data Area Designation */
74 vcpu->arch.sie_block->sidad = __get_free_page(GFP_KERNEL | __GFP_ZERO);
75 if (!vcpu->arch.sie_block->sidad) {
76 free_pages(vcpu->arch.pv.stor_base,
77 get_order(uv_info.guest_cpu_stor_len));
78 return -ENOMEM;
79 }
80
81 cc = uv_call(0, (u64)&uvcb);
82 *rc = uvcb.header.rc;
83 *rrc = uvcb.header.rrc;
84 KVM_UV_EVENT(vcpu->kvm, 3,
85 "PROTVIRT CREATE VCPU: cpu %d handle %llx rc %x rrc %x",
86 vcpu->vcpu_id, uvcb.cpu_handle, uvcb.header.rc,
87 uvcb.header.rrc);
88
89 if (cc) {
90 u16 dummy;
91
92 kvm_s390_pv_destroy_cpu(vcpu, &dummy, &dummy);
93 return -EIO;
94 }
95
96 /* Output */
97 vcpu->arch.pv.handle = uvcb.cpu_handle;
98 vcpu->arch.sie_block->pv_handle_cpu = uvcb.cpu_handle;
99 vcpu->arch.sie_block->pv_handle_config = kvm_s390_pv_get_handle(vcpu->kvm);
100 vcpu->arch.sie_block->sdf = 2;
101 kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
102 return 0;
103 }
104
105 /* only free resources when the destroy was successful */
kvm_s390_pv_dealloc_vm(struct kvm * kvm)106 static void kvm_s390_pv_dealloc_vm(struct kvm *kvm)
107 {
108 vfree(kvm->arch.pv.stor_var);
109 free_pages(kvm->arch.pv.stor_base,
110 get_order(uv_info.guest_base_stor_len));
111 memset(&kvm->arch.pv, 0, sizeof(kvm->arch.pv));
112 }
113
kvm_s390_pv_alloc_vm(struct kvm * kvm)114 static int kvm_s390_pv_alloc_vm(struct kvm *kvm)
115 {
116 unsigned long base = uv_info.guest_base_stor_len;
117 unsigned long virt = uv_info.guest_virt_var_stor_len;
118 unsigned long npages = 0, vlen = 0;
119 struct kvm_memory_slot *memslot;
120
121 kvm->arch.pv.stor_var = NULL;
122 kvm->arch.pv.stor_base = __get_free_pages(GFP_KERNEL, get_order(base));
123 if (!kvm->arch.pv.stor_base)
124 return -ENOMEM;
125
126 /*
127 * Calculate current guest storage for allocation of the
128 * variable storage, which is based on the length in MB.
129 *
130 * Slots are sorted by GFN
131 */
132 mutex_lock(&kvm->slots_lock);
133 memslot = kvm_memslots(kvm)->memslots;
134 npages = memslot->base_gfn + memslot->npages;
135 mutex_unlock(&kvm->slots_lock);
136
137 kvm->arch.pv.guest_len = npages * PAGE_SIZE;
138
139 /* Allocate variable storage */
140 vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE);
141 vlen += uv_info.guest_virt_base_stor_len;
142 kvm->arch.pv.stor_var = vzalloc(vlen);
143 if (!kvm->arch.pv.stor_var)
144 goto out_err;
145 return 0;
146
147 out_err:
148 kvm_s390_pv_dealloc_vm(kvm);
149 return -ENOMEM;
150 }
151
152 /* this should not fail, but if it does, we must not free the donated memory */
kvm_s390_pv_deinit_vm(struct kvm * kvm,u16 * rc,u16 * rrc)153 int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
154 {
155 int cc;
156
157 /* make all pages accessible before destroying the guest */
158 s390_reset_acc(kvm->mm);
159
160 cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm),
161 UVC_CMD_DESTROY_SEC_CONF, rc, rrc);
162 WRITE_ONCE(kvm->arch.gmap->guest_handle, 0);
163 atomic_set(&kvm->mm->context.is_protected, 0);
164 KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM: rc %x rrc %x", *rc, *rrc);
165 WARN_ONCE(cc, "protvirt destroy vm failed rc %x rrc %x", *rc, *rrc);
166 /* Inteded memory leak on "impossible" error */
167 if (!cc)
168 kvm_s390_pv_dealloc_vm(kvm);
169 return cc ? -EIO : 0;
170 }
171
kvm_s390_pv_init_vm(struct kvm * kvm,u16 * rc,u16 * rrc)172 int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
173 {
174 struct uv_cb_cgc uvcb = {
175 .header.cmd = UVC_CMD_CREATE_SEC_CONF,
176 .header.len = sizeof(uvcb)
177 };
178 int cc, ret;
179 u16 dummy;
180
181 ret = kvm_s390_pv_alloc_vm(kvm);
182 if (ret)
183 return ret;
184
185 /* Inputs */
186 uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */
187 uvcb.guest_stor_len = kvm->arch.pv.guest_len;
188 uvcb.guest_asce = kvm->arch.gmap->asce;
189 uvcb.guest_sca = (unsigned long)kvm->arch.sca;
190 uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base;
191 uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;
192
193 cc = uv_call_sched(0, (u64)&uvcb);
194 *rc = uvcb.header.rc;
195 *rrc = uvcb.header.rrc;
196 KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x",
197 uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc);
198
199 /* Outputs */
200 kvm->arch.pv.handle = uvcb.guest_handle;
201
202 if (cc) {
203 if (uvcb.header.rc & UVC_RC_NEED_DESTROY)
204 kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy);
205 else
206 kvm_s390_pv_dealloc_vm(kvm);
207 return -EIO;
208 }
209 kvm->arch.gmap->guest_handle = uvcb.guest_handle;
210 return 0;
211 }
212
kvm_s390_pv_set_sec_parms(struct kvm * kvm,void * hdr,u64 length,u16 * rc,u16 * rrc)213 int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
214 u16 *rrc)
215 {
216 struct uv_cb_ssc uvcb = {
217 .header.cmd = UVC_CMD_SET_SEC_CONF_PARAMS,
218 .header.len = sizeof(uvcb),
219 .sec_header_origin = (u64)hdr,
220 .sec_header_len = length,
221 .guest_handle = kvm_s390_pv_get_handle(kvm),
222 };
223 int cc = uv_call(0, (u64)&uvcb);
224
225 *rc = uvcb.header.rc;
226 *rrc = uvcb.header.rrc;
227 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x",
228 *rc, *rrc);
229 if (!cc)
230 atomic_set(&kvm->mm->context.is_protected, 1);
231 return cc ? -EINVAL : 0;
232 }
233
unpack_one(struct kvm * kvm,unsigned long addr,u64 tweak,u64 offset,u16 * rc,u16 * rrc)234 static int unpack_one(struct kvm *kvm, unsigned long addr, u64 tweak,
235 u64 offset, u16 *rc, u16 *rrc)
236 {
237 struct uv_cb_unp uvcb = {
238 .header.cmd = UVC_CMD_UNPACK_IMG,
239 .header.len = sizeof(uvcb),
240 .guest_handle = kvm_s390_pv_get_handle(kvm),
241 .gaddr = addr,
242 .tweak[0] = tweak,
243 .tweak[1] = offset,
244 };
245 int ret = gmap_make_secure(kvm->arch.gmap, addr, &uvcb);
246
247 *rc = uvcb.header.rc;
248 *rrc = uvcb.header.rrc;
249
250 if (ret && ret != -EAGAIN)
251 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: failed addr %llx with rc %x rrc %x",
252 uvcb.gaddr, *rc, *rrc);
253 return ret;
254 }
255
kvm_s390_pv_unpack(struct kvm * kvm,unsigned long addr,unsigned long size,unsigned long tweak,u16 * rc,u16 * rrc)256 int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
257 unsigned long tweak, u16 *rc, u16 *rrc)
258 {
259 u64 offset = 0;
260 int ret = 0;
261
262 if (addr & ~PAGE_MASK || !size || size & ~PAGE_MASK)
263 return -EINVAL;
264
265 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: start addr %lx size %lx",
266 addr, size);
267
268 while (offset < size) {
269 ret = unpack_one(kvm, addr, tweak, offset, rc, rrc);
270 if (ret == -EAGAIN) {
271 cond_resched();
272 if (fatal_signal_pending(current))
273 break;
274 continue;
275 }
276 if (ret)
277 break;
278 addr += PAGE_SIZE;
279 offset += PAGE_SIZE;
280 }
281 if (!ret)
282 KVM_UV_EVENT(kvm, 3, "%s", "PROTVIRT VM UNPACK: successful");
283 return ret;
284 }
285
kvm_s390_pv_set_cpu_state(struct kvm_vcpu * vcpu,u8 state)286 int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
287 {
288 struct uv_cb_cpu_set_state uvcb = {
289 .header.cmd = UVC_CMD_CPU_SET_STATE,
290 .header.len = sizeof(uvcb),
291 .cpu_handle = kvm_s390_pv_cpu_get_handle(vcpu),
292 .state = state,
293 };
294 int cc;
295
296 cc = uv_call(0, (u64)&uvcb);
297 KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT SET CPU %d STATE %d rc %x rrc %x",
298 vcpu->vcpu_id, state, uvcb.header.rc, uvcb.header.rrc);
299 if (cc)
300 return -EINVAL;
301 return 0;
302 }
303