xemu/hw/scsi/vhost-scsi-common.c
Felipe Franciosi f12c1ebddf vhost-user-scsi: Introduce vhost-user-scsi host device
This commit introduces a vhost-user device for SCSI. This is based
on the existing vhost-scsi implementation, but done over vhost-user
instead. It also uses a chardev to connect to the backend. Unlike
vhost-scsi (today), VMs using vhost-user-scsi can be live migrated.

To use it, start Qemu with a command line equivalent to:

qemu-system-x86_64 \
       -chardev socket,id=vus0,path=/tmp/vus.sock \
       -device vhost-user-scsi-pci,chardev=vus0,bus=pci.0,addr=...

A separate commit presents a sample application linked with libiscsi to
provide a backend for vhost-user-scsi.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Message-Id: <1488479153-21203-4-git-send-email-felipe@nutanix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15 11:18:40 +02:00

143 lines
4.1 KiB
C

/*
* vhost-scsi-common
*
* Copyright (c) 2016 Nutanix Inc. All rights reserved.
*
* Author:
* Felipe Franciosi <felipe@nutanix.com>
*
* This work is largely based on the "vhost-scsi" implementation by:
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
* 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 "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "migration/migration.h"
#include "hw/virtio/vhost.h"
#include "hw/virtio/vhost-scsi-common.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"
int vhost_scsi_common_start(VHostSCSICommon *vsc)
{
int ret, i;
VirtIODevice *vdev = VIRTIO_DEVICE(vsc);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
return -ENOSYS;
}
ret = vhost_dev_enable_notifiers(&vsc->dev, vdev);
if (ret < 0) {
return ret;
}
ret = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, true);
if (ret < 0) {
error_report("Error binding guest notifier");
goto err_host_notifiers;
}
vsc->dev.acked_features = vdev->guest_features;
ret = vhost_dev_start(&vsc->dev, vdev);
if (ret < 0) {
error_report("Error start vhost dev");
goto err_guest_notifiers;
}
/* 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 < vsc->dev.nvqs; i++) {
vhost_virtqueue_mask(&vsc->dev, vdev, vsc->dev.vq_index + i, false);
}
return ret;
err_guest_notifiers:
k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false);
err_host_notifiers:
vhost_dev_disable_notifiers(&vsc->dev, vdev);
return ret;
}
void vhost_scsi_common_stop(VHostSCSICommon *vsc)
{
VirtIODevice *vdev = VIRTIO_DEVICE(vsc);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int ret = 0;
vhost_dev_stop(&vsc->dev, vdev);
if (k->set_guest_notifiers) {
ret = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false);
if (ret < 0) {
error_report("vhost guest notifier cleanup failed: %d", ret);
}
}
assert(ret >= 0);
vhost_dev_disable_notifiers(&vsc->dev, vdev);
}
uint64_t vhost_scsi_common_get_features(VirtIODevice *vdev, uint64_t features,
Error **errp)
{
VHostSCSICommon *vsc = VHOST_SCSI_COMMON(vdev);
return vhost_get_features(&vsc->dev, vsc->feature_bits, features);
}
void vhost_scsi_common_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);
}
}
/*
* Implementation of an interface to adjust firmware path
* for the bootindex property handling.
*/
char *vhost_scsi_common_get_fw_dev_path(FWPathProvider *p, BusState *bus,
DeviceState *dev)
{
VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
/* format: /channel@channel/vhost-scsi@target,lun */
return g_strdup_printf("/channel@%x/%s@%x,%x", vsc->channel,
qdev_fw_name(dev), vsc->target, vsc->lun);
}
static const TypeInfo vhost_scsi_common_info = {
.name = TYPE_VHOST_SCSI_COMMON,
.parent = TYPE_VIRTIO_SCSI_COMMON,
.instance_size = sizeof(VHostSCSICommon),
.abstract = true,
};
static void virtio_register_types(void)
{
type_register_static(&vhost_scsi_common_info);
}
type_init(virtio_register_types)