xref: /qemu/target/s390x/kvm/pv.c (revision c01196bd)
1 /*
2  * Protected Virtualization functions
3  *
4  * Copyright IBM Corp. 2020
5  * Author(s):
6  *  Janosch Frank <frankja@linux.ibm.com>
7  *
8  * This work is licensed under the terms of the GNU GPL, version 2 or (at
9  * your option) any later version. See the COPYING file in the top-level
10  * directory.
11  */
12 #include "qemu/osdep.h"
13 
14 #include <linux/kvm.h>
15 
16 #include "qemu/units.h"
17 #include "qapi/error.h"
18 #include "qemu/error-report.h"
19 #include "sysemu/kvm.h"
20 #include "sysemu/cpus.h"
21 #include "qom/object_interfaces.h"
22 #include "exec/confidential-guest-support.h"
23 #include "hw/s390x/ipl.h"
24 #include "hw/s390x/sclp.h"
25 #include "target/s390x/kvm/kvm_s390x.h"
26 #include "target/s390x/kvm/pv.h"
27 
28 static bool info_valid;
29 static struct kvm_s390_pv_info_vm info_vm;
30 static struct kvm_s390_pv_info_dump info_dump;
31 
32 static int __s390_pv_cmd(uint32_t cmd, const char *cmdname, void *data)
33 {
34     struct kvm_pv_cmd pv_cmd = {
35         .cmd = cmd,
36         .data = (uint64_t)data,
37     };
38     int rc;
39 
40     do {
41         rc = kvm_vm_ioctl(kvm_state, KVM_S390_PV_COMMAND, &pv_cmd);
42     } while (rc == -EINTR);
43 
44     if (rc) {
45         error_report("KVM PV command %d (%s) failed: header rc %x rrc %x "
46                      "IOCTL rc: %d", cmd, cmdname, pv_cmd.rc, pv_cmd.rrc,
47                      rc);
48     }
49     return rc;
50 }
51 
52 /*
53  * This macro lets us pass the command as a string to the function so
54  * we can print it on an error.
55  */
56 #define s390_pv_cmd(cmd, data) __s390_pv_cmd(cmd, #cmd, data)
57 #define s390_pv_cmd_exit(cmd, data)    \
58 {                                      \
59     int rc;                            \
60                                        \
61     rc = __s390_pv_cmd(cmd, #cmd, data);\
62     if (rc) {                          \
63         exit(1);                       \
64     }                                  \
65 }
66 
67 int s390_pv_query_info(void)
68 {
69     struct kvm_s390_pv_info info = {
70         .header.id = KVM_PV_INFO_VM,
71         .header.len_max = sizeof(info.header) + sizeof(info.vm),
72     };
73     int rc;
74 
75     /* Info API's first user is dump so they are bundled */
76     if (!kvm_s390_get_protected_dump()) {
77         return 0;
78     }
79 
80     rc = s390_pv_cmd(KVM_PV_INFO, &info);
81     if (rc) {
82         error_report("KVM PV INFO cmd %x failed: %s",
83                      info.header.id, strerror(-rc));
84         return rc;
85     }
86     memcpy(&info_vm, &info.vm, sizeof(info.vm));
87 
88     info.header.id = KVM_PV_INFO_DUMP;
89     info.header.len_max = sizeof(info.header) + sizeof(info.dump);
90     rc = s390_pv_cmd(KVM_PV_INFO, &info);
91     if (rc) {
92         error_report("KVM PV INFO cmd %x failed: %s",
93                      info.header.id, strerror(-rc));
94         return rc;
95     }
96 
97     memcpy(&info_dump, &info.dump, sizeof(info.dump));
98     info_valid = true;
99 
100     return rc;
101 }
102 
103 int s390_pv_vm_enable(void)
104 {
105     return s390_pv_cmd(KVM_PV_ENABLE, NULL);
106 }
107 
108 void s390_pv_vm_disable(void)
109 {
110      s390_pv_cmd_exit(KVM_PV_DISABLE, NULL);
111 }
112 
113 static void *s390_pv_do_unprot_async_fn(void *p)
114 {
115      s390_pv_cmd_exit(KVM_PV_ASYNC_CLEANUP_PERFORM, NULL);
116      return NULL;
117 }
118 
119 bool s390_pv_vm_try_disable_async(S390CcwMachineState *ms)
120 {
121     /*
122      * t is only needed to create the thread; once qemu_thread_create
123      * returns, it can safely be discarded.
124      */
125     QemuThread t;
126 
127     /*
128      * If the feature is not present or if the VM is not larger than 2 GiB,
129      * KVM_PV_ASYNC_CLEANUP_PREPARE fill fail; no point in attempting it.
130      */
131     if ((MACHINE(ms)->maxram_size <= 2 * GiB) ||
132         !kvm_check_extension(kvm_state, KVM_CAP_S390_PROTECTED_ASYNC_DISABLE)) {
133         return false;
134     }
135     if (s390_pv_cmd(KVM_PV_ASYNC_CLEANUP_PREPARE, NULL) != 0) {
136         return false;
137     }
138 
139     qemu_thread_create(&t, "async_cleanup", s390_pv_do_unprot_async_fn, NULL,
140                        QEMU_THREAD_DETACHED);
141 
142     return true;
143 }
144 
145 int s390_pv_set_sec_parms(uint64_t origin, uint64_t length)
146 {
147     struct kvm_s390_pv_sec_parm args = {
148         .origin = origin,
149         .length = length,
150     };
151 
152     return s390_pv_cmd(KVM_PV_SET_SEC_PARMS, &args);
153 }
154 
155 /*
156  * Called for each component in the SE type IPL parameter block 0.
157  */
158 int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t tweak)
159 {
160     struct kvm_s390_pv_unp args = {
161         .addr = addr,
162         .size = size,
163         .tweak = tweak,
164     };
165 
166     return s390_pv_cmd(KVM_PV_UNPACK, &args);
167 }
168 
169 void s390_pv_prep_reset(void)
170 {
171     s390_pv_cmd_exit(KVM_PV_PREP_RESET, NULL);
172 }
173 
174 int s390_pv_verify(void)
175 {
176     return s390_pv_cmd(KVM_PV_VERIFY, NULL);
177 }
178 
179 void s390_pv_unshare(void)
180 {
181     s390_pv_cmd_exit(KVM_PV_UNSHARE_ALL, NULL);
182 }
183 
184 void s390_pv_inject_reset_error(CPUState *cs)
185 {
186     int r1 = (cs->kvm_run->s390_sieic.ipa & 0x00f0) >> 4;
187     CPUS390XState *env = &S390_CPU(cs)->env;
188 
189     /* Report that we are unable to enter protected mode */
190     env->regs[r1 + 1] = DIAG_308_RC_INVAL_FOR_PV;
191 }
192 
193 uint64_t kvm_s390_pv_dmp_get_size_cpu(void)
194 {
195     return info_dump.dump_cpu_buffer_len;
196 }
197 
198 uint64_t kvm_s390_pv_dmp_get_size_completion_data(void)
199 {
200     return info_dump.dump_config_finalize_len;
201 }
202 
203 uint64_t kvm_s390_pv_dmp_get_size_mem_state(void)
204 {
205     return info_dump.dump_config_mem_buffer_per_1m;
206 }
207 
208 bool kvm_s390_pv_info_basic_valid(void)
209 {
210     return info_valid;
211 }
212 
213 static int s390_pv_dump_cmd(uint64_t subcmd, uint64_t uaddr, uint64_t gaddr,
214                             uint64_t len)
215 {
216     struct kvm_s390_pv_dmp dmp = {
217         .subcmd = subcmd,
218         .buff_addr = uaddr,
219         .buff_len = len,
220         .gaddr = gaddr,
221     };
222     int ret;
223 
224     ret = s390_pv_cmd(KVM_PV_DUMP, (void *)&dmp);
225     if (ret) {
226         error_report("KVM DUMP command %ld failed", subcmd);
227     }
228     return ret;
229 }
230 
231 int kvm_s390_dump_cpu(S390CPU *cpu, void *buff)
232 {
233     struct kvm_s390_pv_dmp dmp = {
234         .subcmd = KVM_PV_DUMP_CPU,
235         .buff_addr = (uint64_t)buff,
236         .gaddr = 0,
237         .buff_len = info_dump.dump_cpu_buffer_len,
238     };
239     struct kvm_pv_cmd pv = {
240         .cmd = KVM_PV_DUMP,
241         .data = (uint64_t)&dmp,
242     };
243 
244     return kvm_vcpu_ioctl(CPU(cpu), KVM_S390_PV_CPU_COMMAND, &pv);
245 }
246 
247 int kvm_s390_dump_init(void)
248 {
249     return s390_pv_dump_cmd(KVM_PV_DUMP_INIT, 0, 0, 0);
250 }
251 
252 int kvm_s390_dump_mem_state(uint64_t gaddr, size_t len, void *dest)
253 {
254     return s390_pv_dump_cmd(KVM_PV_DUMP_CONFIG_STOR_STATE, (uint64_t)dest,
255                             gaddr, len);
256 }
257 
258 int kvm_s390_dump_completion_data(void *buff)
259 {
260     return s390_pv_dump_cmd(KVM_PV_DUMP_COMPLETE, (uint64_t)buff, 0,
261                             info_dump.dump_config_finalize_len);
262 }
263 
264 #define TYPE_S390_PV_GUEST "s390-pv-guest"
265 OBJECT_DECLARE_SIMPLE_TYPE(S390PVGuest, S390_PV_GUEST)
266 
267 /**
268  * S390PVGuest:
269  *
270  * The S390PVGuest object is basically a dummy used to tell the
271  * confidential guest support system to use s390's PV mechanism.
272  *
273  * # $QEMU \
274  *         -object s390-pv-guest,id=pv0 \
275  *         -machine ...,confidential-guest-support=pv0
276  */
277 struct S390PVGuest {
278     ConfidentialGuestSupport parent_obj;
279 };
280 
281 typedef struct S390PVGuestClass S390PVGuestClass;
282 
283 struct S390PVGuestClass {
284     ConfidentialGuestSupportClass parent_class;
285 };
286 
287 /*
288  * If protected virtualization is enabled, the amount of data that the
289  * Read SCP Info Service Call can use is limited to one page. The
290  * available space also depends on the Extended-Length SCCB (ELS)
291  * feature which can take more buffer space to store feature
292  * information. This impacts the maximum number of CPUs supported in
293  * the machine.
294  */
295 static uint32_t s390_pv_get_max_cpus(void)
296 {
297     int offset_cpu = s390_has_feat(S390_FEAT_EXTENDED_LENGTH_SCCB) ?
298         offsetof(ReadInfo, entries) : SCLP_READ_SCP_INFO_FIXED_CPU_OFFSET;
299 
300     return (TARGET_PAGE_SIZE - offset_cpu) / sizeof(CPUEntry);
301 }
302 
303 static bool s390_pv_check_cpus(Error **errp)
304 {
305     MachineState *ms = MACHINE(qdev_get_machine());
306     uint32_t pv_max_cpus = s390_pv_get_max_cpus();
307 
308     if (ms->smp.max_cpus > pv_max_cpus) {
309         error_setg(errp, "Protected VMs support a maximum of %d CPUs",
310                    pv_max_cpus);
311         return false;
312     }
313 
314     return true;
315 }
316 
317 static bool s390_pv_guest_check(ConfidentialGuestSupport *cgs, Error **errp)
318 {
319     return s390_pv_check_cpus(errp);
320 }
321 
322 int s390_pv_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
323 {
324     if (!object_dynamic_cast(OBJECT(cgs), TYPE_S390_PV_GUEST)) {
325         return 0;
326     }
327 
328     if (!s390_has_feat(S390_FEAT_UNPACK)) {
329         error_setg(errp,
330                    "CPU model does not support Protected Virtualization");
331         return -1;
332     }
333 
334     if (!s390_pv_guest_check(cgs, errp)) {
335         return -1;
336     }
337 
338     cgs->ready = true;
339 
340     return 0;
341 }
342 
343 OBJECT_DEFINE_TYPE_WITH_INTERFACES(S390PVGuest,
344                                    s390_pv_guest,
345                                    S390_PV_GUEST,
346                                    CONFIDENTIAL_GUEST_SUPPORT,
347                                    { TYPE_USER_CREATABLE },
348                                    { NULL })
349 
350 static void s390_pv_guest_class_init(ObjectClass *oc, void *data)
351 {
352 }
353 
354 static void s390_pv_guest_init(Object *obj)
355 {
356 }
357 
358 static void s390_pv_guest_finalize(Object *obj)
359 {
360 }
361