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