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_ACCOUNT,
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_ACCOUNT | __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
120 kvm->arch.pv.stor_var = NULL;
121 kvm->arch.pv.stor_base = __get_free_pages(GFP_KERNEL_ACCOUNT, get_order(base));
122 if (!kvm->arch.pv.stor_base)
123 return -ENOMEM;
124
125 /*
126 * Calculate current guest storage for allocation of the
127 * variable storage, which is based on the length in MB.
128 *
129 * Slots are sorted by GFN
130 */
131 mutex_lock(&kvm->slots_lock);
132 npages = kvm_s390_get_gfn_end(kvm_memslots(kvm));
133 mutex_unlock(&kvm->slots_lock);
134
135 kvm->arch.pv.guest_len = npages * PAGE_SIZE;
136
137 /* Allocate variable storage */
138 vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE);
139 vlen += uv_info.guest_virt_base_stor_len;
140 kvm->arch.pv.stor_var = vzalloc(vlen);
141 if (!kvm->arch.pv.stor_var)
142 goto out_err;
143 return 0;
144
145 out_err:
146 kvm_s390_pv_dealloc_vm(kvm);
147 return -ENOMEM;
148 }
149
150 /* 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)151 int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
152 {
153 int cc;
154
155 /* make all pages accessible before destroying the guest */
156 s390_reset_acc(kvm->mm);
157
158 cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm),
159 UVC_CMD_DESTROY_SEC_CONF, rc, rrc);
160 WRITE_ONCE(kvm->arch.gmap->guest_handle, 0);
161 atomic_set(&kvm->mm->context.is_protected, 0);
162 KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM: rc %x rrc %x", *rc, *rrc);
163 WARN_ONCE(cc, "protvirt destroy vm failed rc %x rrc %x", *rc, *rrc);
164 /* Intended memory leak on "impossible" error */
165 if (!cc) {
166 kvm_s390_pv_dealloc_vm(kvm);
167 return 0;
168 }
169 s390_replace_asce(kvm->arch.gmap);
170 return -EIO;
171 }
172
kvm_s390_pv_init_vm(struct kvm * kvm,u16 * rc,u16 * rrc)173 int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
174 {
175 struct uv_cb_cgc uvcb = {
176 .header.cmd = UVC_CMD_CREATE_SEC_CONF,
177 .header.len = sizeof(uvcb)
178 };
179 int cc, ret;
180 u16 dummy;
181
182 ret = kvm_s390_pv_alloc_vm(kvm);
183 if (ret)
184 return ret;
185
186 /* Inputs */
187 uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */
188 uvcb.guest_stor_len = kvm->arch.pv.guest_len;
189 uvcb.guest_asce = kvm->arch.gmap->asce;
190 uvcb.guest_sca = (unsigned long)kvm->arch.sca;
191 uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base;
192 uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;
193
194 cc = uv_call_sched(0, (u64)&uvcb);
195 *rc = uvcb.header.rc;
196 *rrc = uvcb.header.rrc;
197 KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x",
198 uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc);
199
200 /* Outputs */
201 kvm->arch.pv.handle = uvcb.guest_handle;
202
203 if (cc) {
204 if (uvcb.header.rc & UVC_RC_NEED_DESTROY)
205 kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy);
206 else
207 kvm_s390_pv_dealloc_vm(kvm);
208 return -EIO;
209 }
210 kvm->arch.gmap->guest_handle = uvcb.guest_handle;
211 return 0;
212 }
213
kvm_s390_pv_set_sec_parms(struct kvm * kvm,void * hdr,u64 length,u16 * rc,u16 * rrc)214 int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
215 u16 *rrc)
216 {
217 struct uv_cb_ssc uvcb = {
218 .header.cmd = UVC_CMD_SET_SEC_CONF_PARAMS,
219 .header.len = sizeof(uvcb),
220 .sec_header_origin = (u64)hdr,
221 .sec_header_len = length,
222 .guest_handle = kvm_s390_pv_get_handle(kvm),
223 };
224 int cc = uv_call(0, (u64)&uvcb);
225
226 *rc = uvcb.header.rc;
227 *rrc = uvcb.header.rrc;
228 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x",
229 *rc, *rrc);
230 if (!cc)
231 atomic_set(&kvm->mm->context.is_protected, 1);
232 return cc ? -EINVAL : 0;
233 }
234
unpack_one(struct kvm * kvm,unsigned long addr,u64 tweak,u64 offset,u16 * rc,u16 * rrc)235 static int unpack_one(struct kvm *kvm, unsigned long addr, u64 tweak,
236 u64 offset, u16 *rc, u16 *rrc)
237 {
238 struct uv_cb_unp uvcb = {
239 .header.cmd = UVC_CMD_UNPACK_IMG,
240 .header.len = sizeof(uvcb),
241 .guest_handle = kvm_s390_pv_get_handle(kvm),
242 .gaddr = addr,
243 .tweak[0] = tweak,
244 .tweak[1] = offset,
245 };
246 int ret = gmap_make_secure(kvm->arch.gmap, addr, &uvcb);
247
248 *rc = uvcb.header.rc;
249 *rrc = uvcb.header.rrc;
250
251 if (ret && ret != -EAGAIN)
252 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: failed addr %llx with rc %x rrc %x",
253 uvcb.gaddr, *rc, *rrc);
254 return ret;
255 }
256
kvm_s390_pv_unpack(struct kvm * kvm,unsigned long addr,unsigned long size,unsigned long tweak,u16 * rc,u16 * rrc)257 int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
258 unsigned long tweak, u16 *rc, u16 *rrc)
259 {
260 u64 offset = 0;
261 int ret = 0;
262
263 if (addr & ~PAGE_MASK || !size || size & ~PAGE_MASK)
264 return -EINVAL;
265
266 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: start addr %lx size %lx",
267 addr, size);
268
269 while (offset < size) {
270 ret = unpack_one(kvm, addr, tweak, offset, rc, rrc);
271 if (ret == -EAGAIN) {
272 cond_resched();
273 if (fatal_signal_pending(current))
274 break;
275 continue;
276 }
277 if (ret)
278 break;
279 addr += PAGE_SIZE;
280 offset += PAGE_SIZE;
281 }
282 if (!ret)
283 KVM_UV_EVENT(kvm, 3, "%s", "PROTVIRT VM UNPACK: successful");
284 return ret;
285 }
286
kvm_s390_pv_set_cpu_state(struct kvm_vcpu * vcpu,u8 state)287 int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
288 {
289 struct uv_cb_cpu_set_state uvcb = {
290 .header.cmd = UVC_CMD_CPU_SET_STATE,
291 .header.len = sizeof(uvcb),
292 .cpu_handle = kvm_s390_pv_cpu_get_handle(vcpu),
293 .state = state,
294 };
295 int cc;
296
297 cc = uv_call(0, (u64)&uvcb);
298 KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT SET CPU %d STATE %d rc %x rrc %x",
299 vcpu->vcpu_id, state, uvcb.header.rc, uvcb.header.rrc);
300 if (cc)
301 return -EINVAL;
302 return 0;
303 }
304