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 28 typedef struct VirtIODeviceRequest { 29 VirtQueueElement elem; 30 int fd; 31 VirtIOPMEM *pmem; 32 VirtIODevice *vdev; 33 struct virtio_pmem_req req; 34 struct virtio_pmem_resp resp; 35 } VirtIODeviceRequest; 36 37 static int worker_cb(void *opaque) 38 { 39 VirtIODeviceRequest *req_data = opaque; 40 int err = 0; 41 42 /* flush raw backing image */ 43 err = fsync(req_data->fd); 44 if (err != 0) { 45 err = 1; 46 } 47 48 virtio_stw_p(req_data->vdev, &req_data->resp.ret, err); 49 50 return 0; 51 } 52 53 static void done_cb(void *opaque, int ret) 54 { 55 VirtIODeviceRequest *req_data = opaque; 56 int len = iov_from_buf(req_data->elem.in_sg, req_data->elem.in_num, 0, 57 &req_data->resp, sizeof(struct virtio_pmem_resp)); 58 59 /* Callbacks are serialized, so no need to use atomic ops. */ 60 virtqueue_push(req_data->pmem->rq_vq, &req_data->elem, len); 61 virtio_notify((VirtIODevice *)req_data->pmem, req_data->pmem->rq_vq); 62 g_free(req_data); 63 } 64 65 static void virtio_pmem_flush(VirtIODevice *vdev, VirtQueue *vq) 66 { 67 VirtIODeviceRequest *req_data; 68 VirtIOPMEM *pmem = VIRTIO_PMEM(vdev); 69 HostMemoryBackend *backend = MEMORY_BACKEND(pmem->memdev); 70 ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context()); 71 72 req_data = virtqueue_pop(vq, sizeof(VirtIODeviceRequest)); 73 if (!req_data) { 74 virtio_error(vdev, "virtio-pmem missing request data"); 75 return; 76 } 77 78 if (req_data->elem.out_num < 1 || req_data->elem.in_num < 1) { 79 virtio_error(vdev, "virtio-pmem request not proper"); 80 g_free(req_data); 81 return; 82 } 83 req_data->fd = memory_region_get_fd(&backend->mr); 84 req_data->pmem = pmem; 85 req_data->vdev = vdev; 86 thread_pool_submit_aio(pool, worker_cb, req_data, done_cb, req_data); 87 } 88 89 static void virtio_pmem_get_config(VirtIODevice *vdev, uint8_t *config) 90 { 91 VirtIOPMEM *pmem = VIRTIO_PMEM(vdev); 92 struct virtio_pmem_config *pmemcfg = (struct virtio_pmem_config *) config; 93 94 virtio_stq_p(vdev, &pmemcfg->start, pmem->start); 95 virtio_stq_p(vdev, &pmemcfg->size, memory_region_size(&pmem->memdev->mr)); 96 } 97 98 static uint64_t virtio_pmem_get_features(VirtIODevice *vdev, uint64_t features, 99 Error **errp) 100 { 101 return features; 102 } 103 104 static void virtio_pmem_realize(DeviceState *dev, Error **errp) 105 { 106 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 107 VirtIOPMEM *pmem = VIRTIO_PMEM(dev); 108 109 if (!pmem->memdev) { 110 error_setg(errp, "virtio-pmem memdev not set"); 111 return; 112 } 113 114 if (host_memory_backend_is_mapped(pmem->memdev)) { 115 char *path = object_get_canonical_path_component(OBJECT(pmem->memdev)); 116 error_setg(errp, "can't use already busy memdev: %s", path); 117 g_free(path); 118 return; 119 } 120 121 host_memory_backend_set_mapped(pmem->memdev, true); 122 virtio_init(vdev, TYPE_VIRTIO_PMEM, VIRTIO_ID_PMEM, 123 sizeof(struct virtio_pmem_config)); 124 pmem->rq_vq = virtio_add_queue(vdev, 128, virtio_pmem_flush); 125 } 126 127 static void virtio_pmem_unrealize(DeviceState *dev) 128 { 129 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 130 VirtIOPMEM *pmem = VIRTIO_PMEM(dev); 131 132 host_memory_backend_set_mapped(pmem->memdev, false); 133 virtio_delete_queue(pmem->rq_vq); 134 virtio_cleanup(vdev); 135 } 136 137 static void virtio_pmem_fill_device_info(const VirtIOPMEM *pmem, 138 VirtioPMEMDeviceInfo *vi) 139 { 140 vi->memaddr = pmem->start; 141 vi->size = memory_region_size(&pmem->memdev->mr); 142 vi->memdev = object_get_canonical_path(OBJECT(pmem->memdev)); 143 } 144 145 static MemoryRegion *virtio_pmem_get_memory_region(VirtIOPMEM *pmem, 146 Error **errp) 147 { 148 if (!pmem->memdev) { 149 error_setg(errp, "'%s' property must be set", VIRTIO_PMEM_MEMDEV_PROP); 150 return NULL; 151 } 152 153 return &pmem->memdev->mr; 154 } 155 156 static Property virtio_pmem_properties[] = { 157 DEFINE_PROP_UINT64(VIRTIO_PMEM_ADDR_PROP, VirtIOPMEM, start, 0), 158 DEFINE_PROP_LINK(VIRTIO_PMEM_MEMDEV_PROP, VirtIOPMEM, memdev, 159 TYPE_MEMORY_BACKEND, HostMemoryBackend *), 160 DEFINE_PROP_END_OF_LIST(), 161 }; 162 163 static void virtio_pmem_class_init(ObjectClass *klass, void *data) 164 { 165 DeviceClass *dc = DEVICE_CLASS(klass); 166 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 167 VirtIOPMEMClass *vpc = VIRTIO_PMEM_CLASS(klass); 168 169 device_class_set_props(dc, virtio_pmem_properties); 170 171 vdc->realize = virtio_pmem_realize; 172 vdc->unrealize = virtio_pmem_unrealize; 173 vdc->get_config = virtio_pmem_get_config; 174 vdc->get_features = virtio_pmem_get_features; 175 176 vpc->fill_device_info = virtio_pmem_fill_device_info; 177 vpc->get_memory_region = virtio_pmem_get_memory_region; 178 } 179 180 static TypeInfo virtio_pmem_info = { 181 .name = TYPE_VIRTIO_PMEM, 182 .parent = TYPE_VIRTIO_DEVICE, 183 .class_size = sizeof(VirtIOPMEMClass), 184 .class_init = virtio_pmem_class_init, 185 .instance_size = sizeof(VirtIOPMEM), 186 }; 187 188 static void virtio_register_types(void) 189 { 190 type_register_static(&virtio_pmem_info); 191 } 192 193 type_init(virtio_register_types) 194