hw/scsi/vhost-scsi.c - qemu - Git at Google

 /*
  * vhost_scsi host device
  *
  * Copyright IBM, Corp. 2011
  *
  * Authors:
  *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
  *
  * Changes for QEMU mainline + tcm_vhost kernel upstream:
  *  Nicholas Bellinger <nab@risingtidesystems.com>
  *
  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
  * See the COPYING.LIB file in the top-level directory.
  *
  */

 #include <sys/ioctl.h>
 #include "config.h"
 #include "qemu/queue.h"
 #include "monitor/monitor.h"
 #include "migration/migration.h"
 #include "hw/virtio/vhost-scsi.h"
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/virtio-scsi.h"
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/virtio-access.h"
 #include "hw/fw-path-provider.h"

 /* Features supported by host kernel. */
 static const int kernel_feature_bits[] = {
     VIRTIO_F_NOTIFY_ON_EMPTY,
     VIRTIO_RING_F_INDIRECT_DESC,
     VIRTIO_RING_F_EVENT_IDX,
     VIRTIO_SCSI_F_HOTPLUG,
     VHOST_INVALID_FEATURE_BIT
 };

 static int vhost_scsi_set_endpoint(VHostSCSI *s)
 {
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
     const VhostOps *vhost_ops = s->dev.vhost_ops;
     struct vhost_scsi_target backend;
     int ret;

     memset(&backend, 0, sizeof(backend));
     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
     ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
     if (ret < 0) {
         return -errno;
     }
     return 0;
 }

 static void vhost_scsi_clear_endpoint(VHostSCSI *s)
 {
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
     struct vhost_scsi_target backend;
     const VhostOps *vhost_ops = s->dev.vhost_ops;

     memset(&backend, 0, sizeof(backend));
     pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
     vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
 }

 static int vhost_scsi_start(VHostSCSI *s)
 {
     int ret, abi_version, i;
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     const VhostOps *vhost_ops = s->dev.vhost_ops;

     if (!k->set_guest_notifiers) {
         error_report("binding does not support guest notifiers");
         return -ENOSYS;
     }

     ret = vhost_ops->vhost_call(&s->dev,
                                 VHOST_SCSI_GET_ABI_VERSION, &abi_version);
     if (ret < 0) {
         return -errno;
     }
     if (abi_version > VHOST_SCSI_ABI_VERSION) {
         error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
                      " %d is greater than vhost_scsi userspace supports: %d, please"
                      " upgrade your version of QEMU\n", abi_version,
                      VHOST_SCSI_ABI_VERSION);
         return -ENOSYS;
     }

     ret = vhost_dev_enable_notifiers(&s->dev, vdev);
     if (ret < 0) {
         return ret;
     }

     s->dev.acked_features = vdev->guest_features;
     ret = vhost_dev_start(&s->dev, vdev);
     if (ret < 0) {
         error_report("Error start vhost dev");
         goto err_notifiers;
     }

     ret = vhost_scsi_set_endpoint(s);
     if (ret < 0) {
         error_report("Error set vhost-scsi endpoint");
         goto err_vhost_stop;
     }

     ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
     if (ret < 0) {
         error_report("Error binding guest notifier");
         goto err_endpoint;
     }

     /* guest_notifier_mask/pending not used yet, so just unmask
      * everything here.  virtio-pci will do the right thing by
      * enabling/disabling irqfd.
      */
     for (i = 0; i < s->dev.nvqs; i++) {
         vhost_virtqueue_mask(&s->dev, vdev, i, false);
     }

     return ret;

 err_endpoint:
     vhost_scsi_clear_endpoint(s);
 err_vhost_stop:
     vhost_dev_stop(&s->dev, vdev);
 err_notifiers:
     vhost_dev_disable_notifiers(&s->dev, vdev);
     return ret;
 }

 static void vhost_scsi_stop(VHostSCSI *s)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     int ret = 0;

     if (k->set_guest_notifiers) {
         ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
         if (ret < 0) {
                 error_report("vhost guest notifier cleanup failed: %d\n", ret);
         }
     }
     assert(ret >= 0);

     vhost_scsi_clear_endpoint(s);
     vhost_dev_stop(&s->dev, vdev);
     vhost_dev_disable_notifiers(&s->dev, vdev);
 }

 static uint32_t vhost_scsi_get_features(VirtIODevice *vdev,
                                         uint32_t features)
 {
     VHostSCSI *s = VHOST_SCSI(vdev);

     return vhost_get_features(&s->dev, kernel_feature_bits, features);
 }

 static void vhost_scsi_set_config(VirtIODevice *vdev,
                                   const uint8_t *config)
 {
     VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);

     if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size ||
         (uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) {
         error_report("vhost-scsi does not support changing the sense data and CDB sizes");
         exit(1);
     }
 }

 static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
 {
     VHostSCSI *s = (VHostSCSI *)vdev;
     bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);

     if (s->dev.started == start) {
         return;
     }

     if (start) {
         int ret;

         ret = vhost_scsi_start(s);
         if (ret < 0) {
             error_report("virtio-scsi: unable to start vhost: %s\n",
                          strerror(-ret));

             /* There is no userspace virtio-scsi fallback so exit */
             exit(1);
         }
     } else {
         vhost_scsi_stop(s);
     }
 }

 static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 {
 }

 static void vhost_scsi_realize(DeviceState *dev, Error **errp)
 {
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
     VHostSCSI *s = VHOST_SCSI(dev);
     Error *err = NULL;
     int vhostfd = -1;
     int ret;

     if (!vs->conf.wwpn) {
         error_setg(errp, "vhost-scsi: missing wwpn");
         return;
     }

     if (vs->conf.vhostfd) {
         vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, &err);
         if (vhostfd == -1) {
             error_setg(errp, "vhost-scsi: unable to parse vhostfd: %s",
                        error_get_pretty(err));
             error_free(err);
             return;
         }
     } else {
         vhostfd = open("/dev/vhost-scsi", O_RDWR);
         if (vhostfd < 0) {
             error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
                        strerror(errno));
             return;
         }
     }

     virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
                                vhost_dummy_handle_output,
                                vhost_dummy_handle_output);
     if (err != NULL) {
         error_propagate(errp, err);
         close(vhostfd);
         return;
     }

     s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
     s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
     s->dev.vq_index = 0;
     s->dev.backend_features = 0;

     ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
                          VHOST_BACKEND_TYPE_KERNEL, true);
     if (ret < 0) {
         error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
                    strerror(-ret));
         return;
     }

     /* At present, channel and lun both are 0 for bootable vhost-scsi disk */
     s->channel = 0;
     s->lun = 0;
     /* Note: we can also get the minimum tpgt from kernel */
     s->target = vs->conf.boot_tpgt;

     error_setg(&s->migration_blocker,
             "vhost-scsi does not support migration");
     migrate_add_blocker(s->migration_blocker);
 }

 static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VHostSCSI *s = VHOST_SCSI(dev);

     migrate_del_blocker(s->migration_blocker);
     error_free(s->migration_blocker);

     /* This will stop vhost backend. */
     vhost_scsi_set_status(vdev, 0);

     g_free(s->dev.vqs);

     virtio_scsi_common_unrealize(dev, errp);
 }

 /*
  * Implementation of an interface to adjust firmware path
  * for the bootindex property handling.
  */
 static char *vhost_scsi_get_fw_dev_path(FWPathProvider *p, BusState *bus,
                                         DeviceState *dev)
 {
     VHostSCSI *s = VHOST_SCSI(dev);
     /* format: channel@channel/vhost-scsi@target,lun */
     return g_strdup_printf("channel@%x/%s@%x,%x", s->channel,
                            qdev_fw_name(dev), s->target, s->lun);
 }

 static Property vhost_scsi_properties[] = {
     DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent_obj.conf),
     DEFINE_PROP_END_OF_LIST(),
 };

 static void vhost_scsi_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);

     dc->props = vhost_scsi_properties;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
     vdc->realize = vhost_scsi_realize;
     vdc->unrealize = vhost_scsi_unrealize;
     vdc->get_features = vhost_scsi_get_features;
     vdc->set_config = vhost_scsi_set_config;
     vdc->set_status = vhost_scsi_set_status;
     fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
 }

 static void vhost_scsi_instance_init(Object *obj)
 {
     VHostSCSI *dev = VHOST_SCSI(obj);

     device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
                                   DEVICE(dev), NULL);
 }

 static const TypeInfo vhost_scsi_info = {
     .name = TYPE_VHOST_SCSI,
     .parent = TYPE_VIRTIO_SCSI_COMMON,
     .instance_size = sizeof(VHostSCSI),
     .class_init = vhost_scsi_class_init,
     .instance_init = vhost_scsi_instance_init,
     .interfaces = (InterfaceInfo[]) {
         { TYPE_FW_PATH_PROVIDER },
         { }
     },
 };

 static void virtio_register_types(void)
 {
     type_register_static(&vhost_scsi_info);
 }

 type_init(virtio_register_types)
	/*
	* vhost_scsi host device
	*
	* Copyright IBM, Corp. 2011
	*
	* Authors:
	* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
	*
	* Changes for QEMU mainline + tcm_vhost kernel upstream:
	* Nicholas Bellinger <nab@risingtidesystems.com>
	*
	* This work is licensed under the terms of the GNU LGPL, version 2 or later.
	* See the COPYING.LIB file in the top-level directory.
	*
	*/

	#include <sys/ioctl.h>
	#include "config.h"
	#include "qemu/queue.h"
	#include "monitor/monitor.h"
	#include "migration/migration.h"
	#include "hw/virtio/vhost-scsi.h"
	#include "hw/virtio/vhost.h"
	#include "hw/virtio/virtio-scsi.h"
	#include "hw/virtio/virtio-bus.h"
	#include "hw/virtio/virtio-access.h"
	#include "hw/fw-path-provider.h"

	/* Features supported by host kernel. */
	static const int kernel_feature_bits[] = {
	VIRTIO_F_NOTIFY_ON_EMPTY,
	VIRTIO_RING_F_INDIRECT_DESC,
	VIRTIO_RING_F_EVENT_IDX,
	VIRTIO_SCSI_F_HOTPLUG,
	VHOST_INVALID_FEATURE_BIT
	};

	static int vhost_scsi_set_endpoint(VHostSCSI *s)
	{
	VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
	const VhostOps *vhost_ops = s->dev.vhost_ops;
	struct vhost_scsi_target backend;
	int ret;

	memset(&backend, 0, sizeof(backend));
	pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
	ret = vhost_ops->vhost_call(&s->dev, VHOST_SCSI_SET_ENDPOINT, &backend);
	if (ret < 0) {
	return -errno;
	}
	return 0;
	}

	static void vhost_scsi_clear_endpoint(VHostSCSI *s)
	{
	VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
	struct vhost_scsi_target backend;
	const VhostOps *vhost_ops = s->dev.vhost_ops;

	memset(&backend, 0, sizeof(backend));
	pstrcpy(backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->conf.wwpn);
	vhost_ops->vhost_call(&s->dev, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
	}

	static int vhost_scsi_start(VHostSCSI *s)
	{
	int ret, abi_version, i;
	VirtIODevice *vdev = VIRTIO_DEVICE(s);
	BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
	VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
	const VhostOps *vhost_ops = s->dev.vhost_ops;

	if (!k->set_guest_notifiers) {
	error_report("binding does not support guest notifiers");
	return -ENOSYS;
	}

	ret = vhost_ops->vhost_call(&s->dev,
	VHOST_SCSI_GET_ABI_VERSION, &abi_version);
	if (ret < 0) {
	return -errno;
	}
	if (abi_version > VHOST_SCSI_ABI_VERSION) {
	error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
	" %d is greater than vhost_scsi userspace supports: %d, please"
	" upgrade your version of QEMU\n", abi_version,
	VHOST_SCSI_ABI_VERSION);
	return -ENOSYS;
	}

	ret = vhost_dev_enable_notifiers(&s->dev, vdev);
	if (ret < 0) {
	return ret;
	}

	s->dev.acked_features = vdev->guest_features;
	ret = vhost_dev_start(&s->dev, vdev);
	if (ret < 0) {
	error_report("Error start vhost dev");
	goto err_notifiers;
	}

	ret = vhost_scsi_set_endpoint(s);
	if (ret < 0) {
	error_report("Error set vhost-scsi endpoint");
	goto err_vhost_stop;
	}

	ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
	if (ret < 0) {
	error_report("Error binding guest notifier");
	goto err_endpoint;
	}

	/* guest_notifier_mask/pending not used yet, so just unmask
	* everything here. virtio-pci will do the right thing by
	* enabling/disabling irqfd.
	*/
	for (i = 0; i < s->dev.nvqs; i++) {
	vhost_virtqueue_mask(&s->dev, vdev, i, false);
	}

	return ret;

	err_endpoint:
	vhost_scsi_clear_endpoint(s);
	err_vhost_stop:
	vhost_dev_stop(&s->dev, vdev);
	err_notifiers:
	vhost_dev_disable_notifiers(&s->dev, vdev);
	return ret;
	}

	static void vhost_scsi_stop(VHostSCSI *s)
	{
	VirtIODevice *vdev = VIRTIO_DEVICE(s);
	BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
	VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
	int ret = 0;

	if (k->set_guest_notifiers) {
	ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
	if (ret < 0) {
	error_report("vhost guest notifier cleanup failed: %d\n", ret);
	}
	}
	assert(ret >= 0);

	vhost_scsi_clear_endpoint(s);
	vhost_dev_stop(&s->dev, vdev);
	vhost_dev_disable_notifiers(&s->dev, vdev);
	}

	static uint32_t vhost_scsi_get_features(VirtIODevice *vdev,
	uint32_t features)
	{
	VHostSCSI *s = VHOST_SCSI(vdev);

	return vhost_get_features(&s->dev, kernel_feature_bits, features);
	}

	static void vhost_scsi_set_config(VirtIODevice *vdev,
	const uint8_t *config)
	{
	VirtIOSCSIConfig scsiconf = (VirtIOSCSIConfig )config;
	VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);

	if ((uint32_t) virtio_ldl_p(vdev, &scsiconf->sense_size) != vs->sense_size \|\|
	(uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) != vs->cdb_size) {
	error_report("vhost-scsi does not support changing the sense data and CDB sizes");
	exit(1);
	}
	}

	static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val)
	{
	VHostSCSI s = (VHostSCSI )vdev;
	bool start = (val & VIRTIO_CONFIG_S_DRIVER_OK);

	if (s->dev.started == start) {
	return;
	}

	if (start) {
	int ret;

	ret = vhost_scsi_start(s);
	if (ret < 0) {
	error_report("virtio-scsi: unable to start vhost: %s\n",
	strerror(-ret));

	/* There is no userspace virtio-scsi fallback so exit */
	exit(1);
	}
	} else {
	vhost_scsi_stop(s);
	}
	}

	static void vhost_dummy_handle_output(VirtIODevice vdev, VirtQueue vq)
	{
	}

	static void vhost_scsi_realize(DeviceState dev, Error *errp)
	{
	VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
	VHostSCSI *s = VHOST_SCSI(dev);
	Error *err = NULL;
	int vhostfd = -1;
	int ret;

	if (!vs->conf.wwpn) {
	error_setg(errp, "vhost-scsi: missing wwpn");
	return;
	}

	if (vs->conf.vhostfd) {
	vhostfd = monitor_fd_param(cur_mon, vs->conf.vhostfd, &err);
	if (vhostfd == -1) {
	error_setg(errp, "vhost-scsi: unable to parse vhostfd: %s",
	error_get_pretty(err));
	error_free(err);
	return;
	}
	} else {
	vhostfd = open("/dev/vhost-scsi", O_RDWR);
	if (vhostfd < 0) {
	error_setg(errp, "vhost-scsi: open vhost char device failed: %s",
	strerror(errno));
	return;
	}
	}

	virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
	vhost_dummy_handle_output,
	vhost_dummy_handle_output);
	if (err != NULL) {
	error_propagate(errp, err);
	close(vhostfd);
	return;
	}

	s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
	s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
	s->dev.vq_index = 0;
	s->dev.backend_features = 0;

	ret = vhost_dev_init(&s->dev, (void *)(uintptr_t)vhostfd,
	VHOST_BACKEND_TYPE_KERNEL, true);
	if (ret < 0) {
	error_setg(errp, "vhost-scsi: vhost initialization failed: %s",
	strerror(-ret));
	return;
	}

	/* At present, channel and lun both are 0 for bootable vhost-scsi disk */
	s->channel = 0;
	s->lun = 0;
	/* Note: we can also get the minimum tpgt from kernel */
	s->target = vs->conf.boot_tpgt;

	error_setg(&s->migration_blocker,
	"vhost-scsi does not support migration");
	migrate_add_blocker(s->migration_blocker);
	}

	static void vhost_scsi_unrealize(DeviceState dev, Error *errp)
	{
	VirtIODevice *vdev = VIRTIO_DEVICE(dev);
	VHostSCSI *s = VHOST_SCSI(dev);

	migrate_del_blocker(s->migration_blocker);
	error_free(s->migration_blocker);

	/* This will stop vhost backend. */
	vhost_scsi_set_status(vdev, 0);

	g_free(s->dev.vqs);

	virtio_scsi_common_unrealize(dev, errp);
	}

	/*
	* Implementation of an interface to adjust firmware path
	* for the bootindex property handling.
	*/
	static char vhost_scsi_get_fw_dev_path(FWPathProvider p, BusState *bus,
	DeviceState *dev)
	{
	VHostSCSI *s = VHOST_SCSI(dev);
	/* format: channel@channel/vhost-scsi@target,lun */
	return g_strdup_printf("channel@%x/%s@%x,%x", s->channel,
	qdev_fw_name(dev), s->target, s->lun);
	}

	static Property vhost_scsi_properties[] = {
	DEFINE_VHOST_SCSI_PROPERTIES(VHostSCSI, parent_obj.conf),
	DEFINE_PROP_END_OF_LIST(),
	};

	static void vhost_scsi_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
	FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);

	dc->props = vhost_scsi_properties;
	set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
	vdc->realize = vhost_scsi_realize;
	vdc->unrealize = vhost_scsi_unrealize;
	vdc->get_features = vhost_scsi_get_features;
	vdc->set_config = vhost_scsi_set_config;
	vdc->set_status = vhost_scsi_set_status;
	fwc->get_dev_path = vhost_scsi_get_fw_dev_path;
	}

	static void vhost_scsi_instance_init(Object *obj)
	{
	VHostSCSI *dev = VHOST_SCSI(obj);

	device_add_bootindex_property(obj, &dev->bootindex, "bootindex", NULL,
	DEVICE(dev), NULL);
	}

	static const TypeInfo vhost_scsi_info = {
	.name = TYPE_VHOST_SCSI,
	.parent = TYPE_VIRTIO_SCSI_COMMON,
	.instance_size = sizeof(VHostSCSI),
	.class_init = vhost_scsi_class_init,
	.instance_init = vhost_scsi_instance_init,
	.interfaces = (InterfaceInfo[]) {
	{ TYPE_FW_PATH_PROVIDER },
	{ }
	},
	};

	static void virtio_register_types(void)
	{
	type_register_static(&vhost_scsi_info);
	}

	type_init(virtio_register_types)