qemu

virtio-pmem.c (5991B)

---

 /*
  * Virtio PMEM device
  *
  * Copyright (C) 2018-2019 Red Hat, Inc.
  *
  * Authors:
  *  Pankaj Gupta <pagupta@redhat.com>
  *  David Hildenbrand <david@redhat.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2.
  * See the COPYING file in the top-level directory.
  */
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "hw/virtio/virtio-pmem.h"
 #include "hw/qdev-properties.h"
 #include "hw/virtio/virtio-access.h"
 #include "standard-headers/linux/virtio_ids.h"
 #include "standard-headers/linux/virtio_pmem.h"
 #include "sysemu/hostmem.h"
 #include "block/aio.h"
 #include "block/thread-pool.h"
 #include "trace.h"
 
 typedef struct VirtIODeviceRequest {
     VirtQueueElement elem;
     int fd;
     VirtIOPMEM *pmem;
     VirtIODevice *vdev;
     struct virtio_pmem_req req;
     struct virtio_pmem_resp resp;
 } VirtIODeviceRequest;
 
 static int worker_cb(void *opaque)
 {
     VirtIODeviceRequest *req_data = opaque;
     int err = 0;
 
     /* flush raw backing image */
     err = fsync(req_data->fd);
     trace_virtio_pmem_flush_done(err);
     if (err != 0) {
         err = 1;
     }
 
     virtio_stl_p(req_data->vdev, &req_data->resp.ret, err);
 
     return 0;
 }
 
 static void done_cb(void *opaque, int ret)
 {
     VirtIODeviceRequest *req_data = opaque;
     int len = iov_from_buf(req_data->elem.in_sg, req_data->elem.in_num, 0,
                               &req_data->resp, sizeof(struct virtio_pmem_resp));
 
     /* Callbacks are serialized, so no need to use atomic ops. */
     virtqueue_push(req_data->pmem->rq_vq, &req_data->elem, len);
     virtio_notify((VirtIODevice *)req_data->pmem, req_data->pmem->rq_vq);
     trace_virtio_pmem_response();
     g_free(req_data);
 }
 
 static void virtio_pmem_flush(VirtIODevice *vdev, VirtQueue *vq)
 {
     VirtIODeviceRequest *req_data;
     VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);
     HostMemoryBackend *backend = MEMORY_BACKEND(pmem->memdev);
     ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context());
 
     trace_virtio_pmem_flush_request();
     req_data = virtqueue_pop(vq, sizeof(VirtIODeviceRequest));
     if (!req_data) {
         virtio_error(vdev, "virtio-pmem missing request data");
         return;
     }
 
     if (req_data->elem.out_num < 1 || req_data->elem.in_num < 1) {
         virtio_error(vdev, "virtio-pmem request not proper");
         virtqueue_detach_element(vq, (VirtQueueElement *)req_data, 0);
         g_free(req_data);
         return;
     }
     req_data->fd   = memory_region_get_fd(&backend->mr);
     req_data->pmem = pmem;
     req_data->vdev = vdev;
     thread_pool_submit_aio(pool, worker_cb, req_data, done_cb, req_data);
 }
 
 static void virtio_pmem_get_config(VirtIODevice *vdev, uint8_t *config)
 {
     VirtIOPMEM *pmem = VIRTIO_PMEM(vdev);
     struct virtio_pmem_config *pmemcfg = (struct virtio_pmem_config *) config;
 
     virtio_stq_p(vdev, &pmemcfg->start, pmem->start);
     virtio_stq_p(vdev, &pmemcfg->size, memory_region_size(&pmem->memdev->mr));
 }
 
 static uint64_t virtio_pmem_get_features(VirtIODevice *vdev, uint64_t features,
                                         Error **errp)
 {
     return features;
 }
 
 static void virtio_pmem_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOPMEM *pmem = VIRTIO_PMEM(dev);
 
     if (!pmem->memdev) {
         error_setg(errp, "virtio-pmem memdev not set");
         return;
     }
 
     if (host_memory_backend_is_mapped(pmem->memdev)) {
         error_setg(errp, "can't use already busy memdev: %s",
                    object_get_canonical_path_component(OBJECT(pmem->memdev)));
         return;
     }
 
     host_memory_backend_set_mapped(pmem->memdev, true);
     virtio_init(vdev, VIRTIO_ID_PMEM, sizeof(struct virtio_pmem_config));
     pmem->rq_vq = virtio_add_queue(vdev, 128, virtio_pmem_flush);
 }
 
 static void virtio_pmem_unrealize(DeviceState *dev)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOPMEM *pmem = VIRTIO_PMEM(dev);
 
     host_memory_backend_set_mapped(pmem->memdev, false);
     virtio_delete_queue(pmem->rq_vq);
     virtio_cleanup(vdev);
 }
 
 static void virtio_pmem_fill_device_info(const VirtIOPMEM *pmem,
                                          VirtioPMEMDeviceInfo *vi)
 {
     vi->memaddr = pmem->start;
     vi->size    = memory_region_size(&pmem->memdev->mr);
     vi->memdev  = object_get_canonical_path(OBJECT(pmem->memdev));
 }
 
 static MemoryRegion *virtio_pmem_get_memory_region(VirtIOPMEM *pmem,
                                                    Error **errp)
 {
     if (!pmem->memdev) {
         error_setg(errp, "'%s' property must be set", VIRTIO_PMEM_MEMDEV_PROP);
         return NULL;
     }
 
     return &pmem->memdev->mr;
 }
 
 static Property virtio_pmem_properties[] = {
     DEFINE_PROP_UINT64(VIRTIO_PMEM_ADDR_PROP, VirtIOPMEM, start, 0),
     DEFINE_PROP_LINK(VIRTIO_PMEM_MEMDEV_PROP, VirtIOPMEM, memdev,
                      TYPE_MEMORY_BACKEND, HostMemoryBackend *),
     DEFINE_PROP_END_OF_LIST(),
 };
 
 static void virtio_pmem_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
     VirtIOPMEMClass *vpc = VIRTIO_PMEM_CLASS(klass);
 
     device_class_set_props(dc, virtio_pmem_properties);
 
     vdc->realize = virtio_pmem_realize;
     vdc->unrealize = virtio_pmem_unrealize;
     vdc->get_config = virtio_pmem_get_config;
     vdc->get_features = virtio_pmem_get_features;
 
     vpc->fill_device_info = virtio_pmem_fill_device_info;
     vpc->get_memory_region = virtio_pmem_get_memory_region;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 }
 
 static const TypeInfo virtio_pmem_info = {
     .name          = TYPE_VIRTIO_PMEM,
     .parent        = TYPE_VIRTIO_DEVICE,
     .class_size    = sizeof(VirtIOPMEMClass),
     .class_init    = virtio_pmem_class_init,
     .instance_size = sizeof(VirtIOPMEM),
 };
 
 static void virtio_register_types(void)
 {
     type_register_static(&virtio_pmem_info);
 }
 
 type_init(virtio_register_types)