| /* |
| * QEMU sPAPR random number generator "device" for H_RANDOM hypercall |
| * |
| * Copyright 2015 Thomas Huth, Red Hat Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, |
| * or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "qapi/error.h" |
| #include "cpu.h" |
| #include "qemu/error-report.h" |
| #include "qemu/main-loop.h" |
| #include "qemu/module.h" |
| #include "sysemu/device_tree.h" |
| #include "sysemu/rng.h" |
| #include "hw/ppc/spapr.h" |
| #include "hw/qdev-properties.h" |
| #include "kvm_ppc.h" |
| |
| #define SPAPR_RNG(obj) \ |
| OBJECT_CHECK(SpaprRngState, (obj), TYPE_SPAPR_RNG) |
| |
| struct SpaprRngState { |
| /*< private >*/ |
| DeviceState ds; |
| RngBackend *backend; |
| bool use_kvm; |
| }; |
| typedef struct SpaprRngState SpaprRngState; |
| |
| struct HRandomData { |
| QemuSemaphore sem; |
| union { |
| uint64_t v64; |
| uint8_t v8[8]; |
| } val; |
| int received; |
| }; |
| typedef struct HRandomData HRandomData; |
| |
| /* Callback function for the RngBackend */ |
| static void random_recv(void *dest, const void *src, size_t size) |
| { |
| HRandomData *hrdp = dest; |
| |
| if (src && size > 0) { |
| assert(size + hrdp->received <= sizeof(hrdp->val.v8)); |
| memcpy(&hrdp->val.v8[hrdp->received], src, size); |
| hrdp->received += size; |
| } |
| |
| qemu_sem_post(&hrdp->sem); |
| } |
| |
| /* Handler for the H_RANDOM hypercall */ |
| static target_ulong h_random(PowerPCCPU *cpu, SpaprMachineState *spapr, |
| target_ulong opcode, target_ulong *args) |
| { |
| SpaprRngState *rngstate; |
| HRandomData hrdata; |
| |
| rngstate = SPAPR_RNG(object_resolve_path_type("", TYPE_SPAPR_RNG, NULL)); |
| |
| if (!rngstate || !rngstate->backend) { |
| return H_HARDWARE; |
| } |
| |
| qemu_sem_init(&hrdata.sem, 0); |
| hrdata.val.v64 = 0; |
| hrdata.received = 0; |
| |
| while (hrdata.received < 8) { |
| rng_backend_request_entropy(rngstate->backend, 8 - hrdata.received, |
| random_recv, &hrdata); |
| qemu_mutex_unlock_iothread(); |
| qemu_sem_wait(&hrdata.sem); |
| qemu_mutex_lock_iothread(); |
| } |
| |
| qemu_sem_destroy(&hrdata.sem); |
| args[0] = hrdata.val.v64; |
| |
| return H_SUCCESS; |
| } |
| |
| static void spapr_rng_instance_init(Object *obj) |
| { |
| if (object_resolve_path_type("", TYPE_SPAPR_RNG, NULL) != NULL) { |
| error_report("spapr-rng can not be instantiated twice!"); |
| return; |
| } |
| |
| object_property_set_description(obj, "rng", |
| "ID of the random number generator backend", |
| NULL); |
| } |
| |
| static void spapr_rng_realize(DeviceState *dev, Error **errp) |
| { |
| |
| SpaprRngState *rngstate = SPAPR_RNG(dev); |
| |
| if (rngstate->use_kvm) { |
| if (kvmppc_enable_hwrng() == 0) { |
| return; |
| } |
| /* |
| * If user specified both, use-kvm and a backend, we fall back to |
| * the backend now. If not, provide an appropriate error message. |
| */ |
| if (!rngstate->backend) { |
| error_setg(errp, "Could not initialize in-kernel H_RANDOM call!"); |
| return; |
| } |
| } |
| |
| if (rngstate->backend) { |
| spapr_register_hypercall(H_RANDOM, h_random); |
| } else { |
| error_setg(errp, "spapr-rng needs an RNG backend!"); |
| } |
| } |
| |
| static Property spapr_rng_properties[] = { |
| DEFINE_PROP_BOOL("use-kvm", SpaprRngState, use_kvm, false), |
| DEFINE_PROP_LINK("rng", SpaprRngState, backend, TYPE_RNG_BACKEND, |
| RngBackend *), |
| DEFINE_PROP_END_OF_LIST(), |
| }; |
| |
| static void spapr_rng_class_init(ObjectClass *oc, void *data) |
| { |
| DeviceClass *dc = DEVICE_CLASS(oc); |
| |
| dc->realize = spapr_rng_realize; |
| set_bit(DEVICE_CATEGORY_MISC, dc->categories); |
| dc->props = spapr_rng_properties; |
| dc->hotpluggable = false; |
| } |
| |
| static const TypeInfo spapr_rng_info = { |
| .name = TYPE_SPAPR_RNG, |
| .parent = TYPE_DEVICE, |
| .instance_size = sizeof(SpaprRngState), |
| .instance_init = spapr_rng_instance_init, |
| .class_init = spapr_rng_class_init, |
| }; |
| |
| static void spapr_rng_register_type(void) |
| { |
| type_register_static(&spapr_rng_info); |
| } |
| type_init(spapr_rng_register_type) |