1 /* 2 * Virtio PMEM device 3 * 4 * Copyright (C) 2018-2019 Red Hat, Inc. 5 * 6 * Authors: 7 * Pankaj Gupta <pagupta@redhat.com> 8 * David Hildenbrand <david@redhat.com> 9 * 10 * This work is licensed under the terms of the GNU GPL, version 2. 11 * See the COPYING file in the top-level directory. 12 */ 13 14 #include "qemu/osdep.h" 15 #include "qapi/error.h" 16 #include "qemu-common.h" 17 #include "qemu/error-report.h" 18 #include "qemu/main-loop.h" 19 #include "hw/virtio/virtio-pmem.h" 20 #include "hw/qdev-properties.h" 21 #include "hw/virtio/virtio-access.h" 22 #include "standard-headers/linux/virtio_ids.h" 23 #include "standard-headers/linux/virtio_pmem.h" 24 #include "sysemu/hostmem.h" 25 #include "block/aio.h" 26 #include "block/thread-pool.h" 27 #include "trace.h" 28 29 typedef struct VirtIODeviceRequest { 30 VirtQueueElement elem; 31 int fd; 32 VirtIOPMEM *pmem; 33 VirtIODevice *vdev; 34 struct virtio_pmem_req req; 35 struct virtio_pmem_resp resp; 36 } VirtIODeviceRequest; 37 38 static int worker_cb(void *opaque) 39 { 40 VirtIODeviceRequest *req_data = opaque; 41 int err = 0; 42 43 /* flush raw backing image */ 44 err = fsync(req_data->fd); 45 trace_virtio_pmem_flush_done(err); 46 if (err != 0) { 47 err = 1; 48 } 49 50 virtio_stw_p(req_data->vdev, &req_data->resp.ret, err); 51 52 return 0; 53 } 54 55 static void done_cb(void *opaque, int ret) 56 { 57 VirtIODeviceRequest *req_data = opaque; 58 int len = iov_from_buf(req_data->elem.in_sg, req_data->elem.in_num, 0, 59 &req_data->resp, sizeof(struct virtio_pmem_resp)); 60 61 /* Callbacks are serialized, so no need to use atomic ops. */ 62 virtqueue_push(req_data->pmem->rq_vq, &req_data->elem, len); 63 virtio_notify((VirtIODevice *)req_data->pmem, req_data->pmem->rq_vq); 64 trace_virtio_pmem_response(); 65 g_free(req_data); 66 } 67 68 static void virtio_pmem_flush(VirtIODevice *vdev, VirtQueue *vq) 69 { 70 VirtIODeviceRequest *req_data; 71 VirtIOPMEM *pmem = VIRTIO_PMEM(vdev); 72 HostMemoryBackend *backend = MEMORY_BACKEND(pmem->memdev); 73 ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context()); 74 75 trace_virtio_pmem_flush_request(); 76 req_data = virtqueue_pop(vq, sizeof(VirtIODeviceRequest)); 77 if (!req_data) { 78 virtio_error(vdev, "virtio-pmem missing request data"); 79 return; 80 } 81 82 if (req_data->elem.out_num < 1 || req_data->elem.in_num < 1) { 83 virtio_error(vdev, "virtio-pmem request not proper"); 84 virtqueue_detach_element(vq, (VirtQueueElement *)req_data, 0); 85 g_free(req_data); 86 return; 87 } 88 req_data->fd = memory_region_get_fd(&backend->mr); 89 req_data->pmem = pmem; 90 req_data->vdev = vdev; 91 thread_pool_submit_aio(pool, worker_cb, req_data, done_cb, req_data); 92 } 93 94 static void virtio_pmem_get_config(VirtIODevice *vdev, uint8_t *config) 95 { 96 VirtIOPMEM *pmem = VIRTIO_PMEM(vdev); 97 struct virtio_pmem_config *pmemcfg = (struct virtio_pmem_config *) config; 98 99 virtio_stq_p(vdev, &pmemcfg->start, pmem->start); 100 virtio_stq_p(vdev, &pmemcfg->size, memory_region_size(&pmem->memdev->mr)); 101 } 102 103 static uint64_t virtio_pmem_get_features(VirtIODevice *vdev, uint64_t features, 104 Error **errp) 105 { 106 return features; 107 } 108 109 static void virtio_pmem_realize(DeviceState *dev, Error **errp) 110 { 111 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 112 VirtIOPMEM *pmem = VIRTIO_PMEM(dev); 113 114 if (!pmem->memdev) { 115 error_setg(errp, "virtio-pmem memdev not set"); 116 return; 117 } 118 119 if (host_memory_backend_is_mapped(pmem->memdev)) { 120 error_setg(errp, "can't use already busy memdev: %s", 121 object_get_canonical_path_component(OBJECT(pmem->memdev))); 122 return; 123 } 124 125 host_memory_backend_set_mapped(pmem->memdev, true); 126 virtio_init(vdev, TYPE_VIRTIO_PMEM, VIRTIO_ID_PMEM, 127 sizeof(struct virtio_pmem_config)); 128 pmem->rq_vq = virtio_add_queue(vdev, 128, virtio_pmem_flush); 129 } 130 131 static void virtio_pmem_unrealize(DeviceState *dev) 132 { 133 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 134 VirtIOPMEM *pmem = VIRTIO_PMEM(dev); 135 136 host_memory_backend_set_mapped(pmem->memdev, false); 137 virtio_delete_queue(pmem->rq_vq); 138 virtio_cleanup(vdev); 139 } 140 141 static void virtio_pmem_fill_device_info(const VirtIOPMEM *pmem, 142 VirtioPMEMDeviceInfo *vi) 143 { 144 vi->memaddr = pmem->start; 145 vi->size = memory_region_size(&pmem->memdev->mr); 146 vi->memdev = object_get_canonical_path(OBJECT(pmem->memdev)); 147 } 148 149 static MemoryRegion *virtio_pmem_get_memory_region(VirtIOPMEM *pmem, 150 Error **errp) 151 { 152 if (!pmem->memdev) { 153 error_setg(errp, "'%s' property must be set", VIRTIO_PMEM_MEMDEV_PROP); 154 return NULL; 155 } 156 157 return &pmem->memdev->mr; 158 } 159 160 static Property virtio_pmem_properties[] = { 161 DEFINE_PROP_UINT64(VIRTIO_PMEM_ADDR_PROP, VirtIOPMEM, start, 0), 162 DEFINE_PROP_LINK(VIRTIO_PMEM_MEMDEV_PROP, VirtIOPMEM, memdev, 163 TYPE_MEMORY_BACKEND, HostMemoryBackend *), 164 DEFINE_PROP_END_OF_LIST(), 165 }; 166 167 static void virtio_pmem_class_init(ObjectClass *klass, void *data) 168 { 169 DeviceClass *dc = DEVICE_CLASS(klass); 170 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 171 VirtIOPMEMClass *vpc = VIRTIO_PMEM_CLASS(klass); 172 173 device_class_set_props(dc, virtio_pmem_properties); 174 175 vdc->realize = virtio_pmem_realize; 176 vdc->unrealize = virtio_pmem_unrealize; 177 vdc->get_config = virtio_pmem_get_config; 178 vdc->get_features = virtio_pmem_get_features; 179 180 vpc->fill_device_info = virtio_pmem_fill_device_info; 181 vpc->get_memory_region = virtio_pmem_get_memory_region; 182 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 183 } 184 185 static TypeInfo virtio_pmem_info = { 186 .name = TYPE_VIRTIO_PMEM, 187 .parent = TYPE_VIRTIO_DEVICE, 188 .class_size = sizeof(VirtIOPMEMClass), 189 .class_init = virtio_pmem_class_init, 190 .instance_size = sizeof(VirtIOPMEM), 191 }; 192 193 static void virtio_register_types(void) 194 { 195 type_register_static(&virtio_pmem_info); 196 } 197 198 type_init(virtio_register_types) 199