tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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
17int 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
51int 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 */
106static 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
114static 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
145out_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 */
151int 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 /* Inteded memory leak on "impossible" error */
165 if (!cc)
166 kvm_s390_pv_dealloc_vm(kvm);
167 return cc ? -EIO : 0;
168}
169
170int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
171{
172 struct uv_cb_cgc uvcb = {
173 .header.cmd = UVC_CMD_CREATE_SEC_CONF,
174 .header.len = sizeof(uvcb)
175 };
176 int cc, ret;
177 u16 dummy;
178
179 ret = kvm_s390_pv_alloc_vm(kvm);
180 if (ret)
181 return ret;
182
183 /* Inputs */
184 uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */
185 uvcb.guest_stor_len = kvm->arch.pv.guest_len;
186 uvcb.guest_asce = kvm->arch.gmap->asce;
187 uvcb.guest_sca = (unsigned long)kvm->arch.sca;
188 uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base;
189 uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;
190
191 cc = uv_call_sched(0, (u64)&uvcb);
192 *rc = uvcb.header.rc;
193 *rrc = uvcb.header.rrc;
194 KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x",
195 uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc);
196
197 /* Outputs */
198 kvm->arch.pv.handle = uvcb.guest_handle;
199
200 if (cc) {
201 if (uvcb.header.rc & UVC_RC_NEED_DESTROY)
202 kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy);
203 else
204 kvm_s390_pv_dealloc_vm(kvm);
205 return -EIO;
206 }
207 kvm->arch.gmap->guest_handle = uvcb.guest_handle;
208 return 0;
209}
210
211int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
212 u16 *rrc)
213{
214 struct uv_cb_ssc uvcb = {
215 .header.cmd = UVC_CMD_SET_SEC_CONF_PARAMS,
216 .header.len = sizeof(uvcb),
217 .sec_header_origin = (u64)hdr,
218 .sec_header_len = length,
219 .guest_handle = kvm_s390_pv_get_handle(kvm),
220 };
221 int cc = uv_call(0, (u64)&uvcb);
222
223 *rc = uvcb.header.rc;
224 *rrc = uvcb.header.rrc;
225 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x",
226 *rc, *rrc);
227 if (!cc)
228 atomic_set(&kvm->mm->context.is_protected, 1);
229 return cc ? -EINVAL : 0;
230}
231
232static int unpack_one(struct kvm *kvm, unsigned long addr, u64 tweak,
233 u64 offset, u16 *rc, u16 *rrc)
234{
235 struct uv_cb_unp uvcb = {
236 .header.cmd = UVC_CMD_UNPACK_IMG,
237 .header.len = sizeof(uvcb),
238 .guest_handle = kvm_s390_pv_get_handle(kvm),
239 .gaddr = addr,
240 .tweak[0] = tweak,
241 .tweak[1] = offset,
242 };
243 int ret = gmap_make_secure(kvm->arch.gmap, addr, &uvcb);
244
245 *rc = uvcb.header.rc;
246 *rrc = uvcb.header.rrc;
247
248 if (ret && ret != -EAGAIN)
249 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: failed addr %llx with rc %x rrc %x",
250 uvcb.gaddr, *rc, *rrc);
251 return ret;
252}
253
254int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
255 unsigned long tweak, u16 *rc, u16 *rrc)
256{
257 u64 offset = 0;
258 int ret = 0;
259
260 if (addr & ~PAGE_MASK || !size || size & ~PAGE_MASK)
261 return -EINVAL;
262
263 KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: start addr %lx size %lx",
264 addr, size);
265
266 while (offset < size) {
267 ret = unpack_one(kvm, addr, tweak, offset, rc, rrc);
268 if (ret == -EAGAIN) {
269 cond_resched();
270 if (fatal_signal_pending(current))
271 break;
272 continue;
273 }
274 if (ret)
275 break;
276 addr += PAGE_SIZE;
277 offset += PAGE_SIZE;
278 }
279 if (!ret)
280 KVM_UV_EVENT(kvm, 3, "%s", "PROTVIRT VM UNPACK: successful");
281 return ret;
282}
283
284int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
285{
286 struct uv_cb_cpu_set_state uvcb = {
287 .header.cmd = UVC_CMD_CPU_SET_STATE,
288 .header.len = sizeof(uvcb),
289 .cpu_handle = kvm_s390_pv_cpu_get_handle(vcpu),
290 .state = state,
291 };
292 int cc;
293
294 cc = uv_call(0, (u64)&uvcb);
295 KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT SET CPU %d STATE %d rc %x rrc %x",
296 vcpu->vcpu_id, state, uvcb.header.rc, uvcb.header.rrc);
297 if (cc)
298 return -EINVAL;
299 return 0;
300}