diff options
Diffstat (limited to 'src/hw/ppc/spapr_rng.c')
| -rw-r--r-- | src/hw/ppc/spapr_rng.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/hw/ppc/spapr_rng.c b/src/hw/ppc/spapr_rng.c new file mode 100644 index 0000000..ed43d5e --- /dev/null +++ b/src/hw/ppc/spapr_rng.c @@ -0,0 +1,186 @@ +/* + * 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/error-report.h" +#include "sysemu/sysemu.h" +#include "sysemu/device_tree.h" +#include "sysemu/rng.h" +#include "hw/ppc/spapr.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; + + qemu_mutex_unlock_iothread(); + while (hrdata.received < 8) { + rng_backend_request_entropy(rngstate->backend, 8 - hrdata.received, + random_recv, &hrdata); + 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) +{ + sPAPRRngState *rngstate = SPAPR_RNG(obj); + + if (object_resolve_path_type("", TYPE_SPAPR_RNG, NULL) != NULL) { + error_report("spapr-rng can not be instantiated twice!"); + return; + } + + object_property_add_link(obj, "rng", TYPE_RNG_BACKEND, + (Object **)&rngstate->backend, + object_property_allow_set_link, + OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL); + 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!"); + } +} + +int spapr_rng_populate_dt(void *fdt) +{ + int node; + int ret; + + node = qemu_fdt_add_subnode(fdt, "/ibm,platform-facilities"); + if (node <= 0) { + return -1; + } + ret = fdt_setprop_string(fdt, node, "device_type", + "ibm,platform-facilities"); + ret |= fdt_setprop_cell(fdt, node, "#address-cells", 0x1); + ret |= fdt_setprop_cell(fdt, node, "#size-cells", 0x0); + + node = fdt_add_subnode(fdt, node, "ibm,random-v1"); + if (node <= 0) { + return -1; + } + ret |= fdt_setprop_string(fdt, node, "compatible", "ibm,random"); + + return ret ? -1 : 0; +} + +static Property spapr_rng_properties[] = { + DEFINE_PROP_BOOL("use-kvm", sPAPRRngState, use_kvm, false), + 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; +} + +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) |
