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xemu/hw/scsi/virtio-scsi.c
Denis Plotnikov c9b7d9ec21 virtio: increase virtqueue size for virtio-scsi and virtio-blk 
The goal is to reduce the amount of requests issued by a guest on
1M reads/writes. This rises the performance up to 4% on that kind of
disk access pattern.

The maximum chunk size to be used for the guest disk accessing is
limited with seg_max parameter, which represents the max amount of
pices in the scatter-geather list in one guest disk request.

Since seg_max is virqueue_size dependent, increasing the virtqueue
size increases seg_max, which, in turn, increases the maximum size
of data to be read/write from a guest disk.

More details in the original problem statment:
https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg03721.html

Suggested-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Message-id: 20200214074648.958-1-dplotnikov@virtuozzo.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-02-22 08:26:47 +00:00

1050 lines
32 KiB
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/*
* Virtio SCSI HBA
*
* Copyright IBM, Corp. 2010
* Copyright Red Hat, Inc. 2011
*
* Authors:
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
* Paolo Bonzini <pbonzini@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "standard-headers/linux/virtio_ids.h"
#include "hw/virtio/virtio-scsi.h"
#include "migration/qemu-file-types.h"
#include "qemu/error-report.h"
#include "qemu/iov.h"
#include "qemu/module.h"
#include "sysemu/block-backend.h"
#include "hw/qdev-properties.h"
#include "hw/scsi/scsi.h"
#include "scsi/constants.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
static inline int virtio_scsi_get_lun(uint8_t *lun)
{
return ((lun[2] << 8) | lun[3]) & 0x3FFF;
}
static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
{
if (lun[0] != 1) {
return NULL;
}
if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
return NULL;
}
return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
}
void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
{
VirtIODevice *vdev = VIRTIO_DEVICE(s);
const size_t zero_skip =
offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
req->vq = vq;
req->dev = s;
qemu_sglist_init(&req->qsgl, DEVICE(s), 8, vdev->dma_as);
qemu_iovec_init(&req->resp_iov, 1);
memset((uint8_t *)req + zero_skip, 0, sizeof(*req) - zero_skip);
}
void virtio_scsi_free_req(VirtIOSCSIReq *req)
{
qemu_iovec_destroy(&req->resp_iov);
qemu_sglist_destroy(&req->qsgl);
g_free(req);
}
static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
{
VirtIOSCSI *s = req->dev;
VirtQueue *vq = req->vq;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
if (s->dataplane_started && !s->dataplane_fenced) {
virtio_notify_irqfd(vdev, vq);
} else {
virtio_notify(vdev, vq);
}
if (req->sreq) {
req->sreq->hba_private = NULL;
scsi_req_unref(req->sreq);
}
virtio_scsi_free_req(req);
}
static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
{
virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
virtqueue_detach_element(req->vq, &req->elem, 0);
virtio_scsi_free_req(req);
}
static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
hwaddr *addr, int num, size_t skip)
{
QEMUSGList *qsgl = &req->qsgl;
size_t copied = 0;
while (num) {
if (skip >= iov->iov_len) {
skip -= iov->iov_len;
} else {
qemu_sglist_add(qsgl, *addr + skip, iov->iov_len - skip);
copied += iov->iov_len - skip;
skip = 0;
}
iov++;
addr++;
num--;
}
assert(skip == 0);
return copied;
}
static int virtio_scsi_parse_req(VirtIOSCSIReq *req,
unsigned req_size, unsigned resp_size)
{
VirtIODevice *vdev = (VirtIODevice *) req->dev;
size_t in_size, out_size;
if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
&req->req, req_size) < req_size) {
return -EINVAL;
}
if (qemu_iovec_concat_iov(&req->resp_iov,
req->elem.in_sg, req->elem.in_num, 0,
resp_size) < resp_size) {
return -EINVAL;
}
req->resp_size = resp_size;
/* Old BIOSes left some padding by mistake after the req_size/resp_size.
* As a workaround, always consider the first buffer as the virtio-scsi
* request/response, making the payload start at the second element
* of the iovec.
*
* The actual length of the response header, stored in req->resp_size,
* does not change.
*
* TODO: always disable this workaround for virtio 1.0 devices.
*/
if (!virtio_vdev_has_feature(vdev, VIRTIO_F_ANY_LAYOUT)) {
if (req->elem.out_num) {
req_size = req->elem.out_sg[0].iov_len;
}
if (req->elem.in_num) {
resp_size = req->elem.in_sg[0].iov_len;
}
}
out_size = qemu_sgl_concat(req, req->elem.out_sg,
&req->elem.out_addr[0], req->elem.out_num,
req_size);
in_size = qemu_sgl_concat(req, req->elem.in_sg,
&req->elem.in_addr[0], req->elem.in_num,
resp_size);
if (out_size && in_size) {
return -ENOTSUP;
}
if (out_size) {
req->mode = SCSI_XFER_TO_DEV;
} else if (in_size) {
req->mode = SCSI_XFER_FROM_DEV;
}
return 0;
}
static VirtIOSCSIReq *virtio_scsi_pop_req(VirtIOSCSI *s, VirtQueue *vq)
{
VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
VirtIOSCSIReq *req;
req = virtqueue_pop(vq, sizeof(VirtIOSCSIReq) + vs->cdb_size);
if (!req) {
return NULL;
}
virtio_scsi_init_req(s, vq, req);
return req;
}
static void virtio_scsi_save_request(QEMUFile *f, SCSIRequest *sreq)
{
VirtIOSCSIReq *req = sreq->hba_private;
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(req->dev);
VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
uint32_t n = virtio_get_queue_index(req->vq) - 2;
assert(n < vs->conf.num_queues);
qemu_put_be32s(f, &n);
qemu_put_virtqueue_element(vdev, f, &req->elem);
}
static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
{
SCSIBus *bus = sreq->bus;
VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
VirtIODevice *vdev = VIRTIO_DEVICE(s);
VirtIOSCSIReq *req;
uint32_t n;
qemu_get_be32s(f, &n);
assert(n < vs->conf.num_queues);
req = qemu_get_virtqueue_element(vdev, f,
sizeof(VirtIOSCSIReq) + vs->cdb_size);
virtio_scsi_init_req(s, vs->cmd_vqs[n], req);
if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
error_report("invalid SCSI request migration data");
exit(1);
}
scsi_req_ref(sreq);
req->sreq = sreq;
if (req->sreq->cmd.mode != SCSI_XFER_NONE) {
assert(req->sreq->cmd.mode == req->mode);
}
return req;
}
typedef struct {
Notifier notifier;
VirtIOSCSIReq *tmf_req;
} VirtIOSCSICancelNotifier;
static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
{
VirtIOSCSICancelNotifier *n = container_of(notifier,
VirtIOSCSICancelNotifier,
notifier);
if (--n->tmf_req->remaining == 0) {
virtio_scsi_complete_req(n->tmf_req);
}
g_free(n);
}
static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
{
if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
assert(blk_get_aio_context(d->conf.blk) == s->ctx);
}
}
/* Return 0 if the request is ready to be completed and return to guest;
* -EINPROGRESS if the request is submitted and will be completed later, in the
* case of async cancellation. */
static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
SCSIRequest *r, *next;
BusChild *kid;
int target;
int ret = 0;
virtio_scsi_ctx_check(s, d);
/* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE". */
req->resp.tmf.response = VIRTIO_SCSI_S_OK;
/*
* req->req.tmf has the QEMU_PACKED attribute. Don't use virtio_tswap32s()
* to avoid compiler errors.
*/
req->req.tmf.subtype =
virtio_tswap32(VIRTIO_DEVICE(s), req->req.tmf.subtype);
switch (req->req.tmf.subtype) {
case VIRTIO_SCSI_T_TMF_ABORT_TASK:
case VIRTIO_SCSI_T_TMF_QUERY_TASK:
if (!d) {
goto fail;
}
if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
goto incorrect_lun;
}
QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
VirtIOSCSIReq *cmd_req = r->hba_private;
if (cmd_req && cmd_req->req.cmd.tag == req->req.tmf.tag) {
break;
}
}
if (r) {
/*
* Assert that the request has not been completed yet, we
* check for it in the loop above.
*/
assert(r->hba_private);
if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK) {
/* "If the specified command is present in the task set, then
* return a service response set to FUNCTION SUCCEEDED".
*/
req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
} else {
VirtIOSCSICancelNotifier *notifier;
req->remaining = 1;
notifier = g_new(VirtIOSCSICancelNotifier, 1);
notifier->tmf_req = req;
notifier->notifier.notify = virtio_scsi_cancel_notify;
scsi_req_cancel_async(r, &notifier->notifier);
ret = -EINPROGRESS;
}
}
break;
case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
if (!d) {
goto fail;
}
if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
goto incorrect_lun;
}
s->resetting++;
qdev_reset_all(&d->qdev);
s->resetting--;
break;
case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET:
case VIRTIO_SCSI_T_TMF_QUERY_TASK_SET:
if (!d) {
goto fail;
}
if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
goto incorrect_lun;
}
/* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
* This way, if the bus starts calling back to the notifiers
* even before we finish the loop, virtio_scsi_cancel_notify
* will not complete the TMF too early.
*/
req->remaining = 1;
QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
if (r->hba_private) {
if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
/* "If there is any command present in the task set, then
* return a service response set to FUNCTION SUCCEEDED".
*/
req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
break;
} else {
VirtIOSCSICancelNotifier *notifier;
req->remaining++;
notifier = g_new(VirtIOSCSICancelNotifier, 1);
notifier->notifier.notify = virtio_scsi_cancel_notify;
notifier->tmf_req = req;
scsi_req_cancel_async(r, &notifier->notifier);
}
}
}
if (--req->remaining > 0) {
ret = -EINPROGRESS;
}
break;
case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
target = req->req.tmf.lun[1];
s->resetting++;
QTAILQ_FOREACH(kid, &s->bus.qbus.children, sibling) {
d = SCSI_DEVICE(kid->child);
if (d->channel == 0 && d->id == target) {
qdev_reset_all(&d->qdev);
}
}
s->resetting--;
break;
case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
default:
req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
break;
}
return ret;
incorrect_lun:
req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
return ret;
fail:
req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
return ret;
}
static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
VirtIODevice *vdev = (VirtIODevice *)s;
uint32_t type;
int r = 0;
if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
&type, sizeof(type)) < sizeof(type)) {
virtio_scsi_bad_req(req);
return;
}
virtio_tswap32s(vdev, &type);
if (type == VIRTIO_SCSI_T_TMF) {
if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
virtio_scsi_bad_req(req);
return;
} else {
r = virtio_scsi_do_tmf(s, req);
}
} else if (type == VIRTIO_SCSI_T_AN_QUERY ||
type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
sizeof(VirtIOSCSICtrlANResp)) < 0) {
virtio_scsi_bad_req(req);
return;
} else {
req->resp.an.event_actual = 0;
req->resp.an.response = VIRTIO_SCSI_S_OK;
}
}
if (r == 0) {
virtio_scsi_complete_req(req);
} else {
assert(r == -EINPROGRESS);
}
}
bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
{
VirtIOSCSIReq *req;
bool progress = false;
while ((req = virtio_scsi_pop_req(s, vq))) {
progress = true;
virtio_scsi_handle_ctrl_req(s, req);
}
return progress;
}
static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOSCSI *s = (VirtIOSCSI *)vdev;
if (s->ctx) {
virtio_device_start_ioeventfd(vdev);
if (!s->dataplane_fenced) {
return;
}
}
virtio_scsi_acquire(s);
virtio_scsi_handle_ctrl_vq(s, vq);
virtio_scsi_release(s);
}
static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
{
/* Sense data is not in req->resp and is copied separately
* in virtio_scsi_command_complete.
*/
req->resp_size = sizeof(VirtIOSCSICmdResp);
virtio_scsi_complete_req(req);
}
static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
size_t resid)
{
VirtIOSCSIReq *req = r->hba_private;
uint8_t sense[SCSI_SENSE_BUF_SIZE];
uint32_t sense_len;
VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
if (r->io_canceled) {
return;
}
req->resp.cmd.response = VIRTIO_SCSI_S_OK;
req->resp.cmd.status = status;
if (req->resp.cmd.status == GOOD) {
req->resp.cmd.resid = virtio_tswap32(vdev, resid);
} else {
req->resp.cmd.resid = 0;
sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
sense, sense_len);
req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
}
virtio_scsi_complete_cmd_req(req);
}
static int virtio_scsi_parse_cdb(SCSIDevice *dev, SCSICommand *cmd,
uint8_t *buf, void *hba_private)
{
VirtIOSCSIReq *req = hba_private;
if (cmd->len == 0) {
cmd->len = MIN(VIRTIO_SCSI_CDB_DEFAULT_SIZE, SCSI_CMD_BUF_SIZE);
memcpy(cmd->buf, buf, cmd->len);
}
/* Extract the direction and mode directly from the request, for
* host device passthrough.
*/
cmd->xfer = req->qsgl.size;
cmd->mode = req->mode;
return 0;
}
static QEMUSGList *virtio_scsi_get_sg_list(SCSIRequest *r)
{
VirtIOSCSIReq *req = r->hba_private;
return &req->qsgl;
}
static void virtio_scsi_request_cancelled(SCSIRequest *r)
{
VirtIOSCSIReq *req = r->hba_private;
if (!req) {
return;
}
if (req->dev->resetting) {
req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
} else {
req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
}
virtio_scsi_complete_cmd_req(req);
}
static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
{
req->resp.cmd.response = VIRTIO_SCSI_S_FAILURE;
virtio_scsi_complete_cmd_req(req);
}
static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
VirtIOSCSICommon *vs = &s->parent_obj;
SCSIDevice *d;
int rc;
rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
sizeof(VirtIOSCSICmdResp) + vs->sense_size);
if (rc < 0) {
if (rc == -ENOTSUP) {
virtio_scsi_fail_cmd_req(req);
return -ENOTSUP;
} else {
virtio_scsi_bad_req(req);
return -EINVAL;
}
}
d = virtio_scsi_device_find(s, req->req.cmd.lun);
if (!d) {
req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
virtio_scsi_complete_cmd_req(req);
return -ENOENT;
}
virtio_scsi_ctx_check(s, d);
req->sreq = scsi_req_new(d, req->req.cmd.tag,
virtio_scsi_get_lun(req->req.cmd.lun),
req->req.cmd.cdb, req);
if (req->sreq->cmd.mode != SCSI_XFER_NONE
&& (req->sreq->cmd.mode != req->mode ||
req->sreq->cmd.xfer > req->qsgl.size)) {
req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
virtio_scsi_complete_cmd_req(req);
return -ENOBUFS;
}
scsi_req_ref(req->sreq);
blk_io_plug(d->conf.blk);
return 0;
}
static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
SCSIRequest *sreq = req->sreq;
if (scsi_req_enqueue(sreq)) {
scsi_req_continue(sreq);
}
blk_io_unplug(sreq->dev->conf.blk);
scsi_req_unref(sreq);
}
bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
{
VirtIOSCSIReq *req, *next;
int ret = 0;
bool suppress_notifications = virtio_queue_get_notification(vq);
bool progress = false;
QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
do {
if (suppress_notifications) {
virtio_queue_set_notification(vq, 0);
}
while ((req = virtio_scsi_pop_req(s, vq))) {
progress = true;
ret = virtio_scsi_handle_cmd_req_prepare(s, req);
if (!ret) {
QTAILQ_INSERT_TAIL(&reqs, req, next);
} else if (ret == -EINVAL) {
/* The device is broken and shouldn't process any request */
while (!QTAILQ_EMPTY(&reqs)) {
req = QTAILQ_FIRST(&reqs);
QTAILQ_REMOVE(&reqs, req, next);
blk_io_unplug(req->sreq->dev->conf.blk);
scsi_req_unref(req->sreq);
virtqueue_detach_element(req->vq, &req->elem, 0);
virtio_scsi_free_req(req);
}
}
}
if (suppress_notifications) {
virtio_queue_set_notification(vq, 1);
}
} while (ret != -EINVAL && !virtio_queue_empty(vq));
QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
virtio_scsi_handle_cmd_req_submit(s, req);
}
return progress;
}
static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
{
/* use non-QOM casts in the data path */
VirtIOSCSI *s = (VirtIOSCSI *)vdev;
if (s->ctx) {
virtio_device_start_ioeventfd(vdev);
if (!s->dataplane_fenced) {
return;
}
}
virtio_scsi_acquire(s);
virtio_scsi_handle_cmd_vq(s, vq);
virtio_scsi_release(s);
}
static void virtio_scsi_get_config(VirtIODevice *vdev,
uint8_t *config)
{
VirtIOSCSIConfig *scsiconf = (VirtIOSCSIConfig *)config;
VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
virtio_stl_p(vdev, &scsiconf->seg_max,
s->conf.seg_max_adjust ? s->conf.virtqueue_size - 2 : 128 - 2);
virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
virtio_stl_p(vdev, &scsiconf->sense_size, s->sense_size);
virtio_stl_p(vdev, &scsiconf->cdb_size, s->cdb_size);
virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
virtio_stw_p(vdev, &scsiconf->max_target, VIRTIO_SCSI_MAX_TARGET);
virtio_stl_p(vdev, &scsiconf->max_lun, VIRTIO_SCSI_MAX_LUN);
}
static void virtio_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) >= 65536 ||
(uint32_t) virtio_ldl_p(vdev, &scsiconf->cdb_size) >= 256) {
virtio_error(vdev,
"bad data written to virtio-scsi configuration space");
return;
}
vs->sense_size = virtio_ldl_p(vdev, &scsiconf->sense_size);
vs->cdb_size = virtio_ldl_p(vdev, &scsiconf->cdb_size);
}
static uint64_t virtio_scsi_get_features(VirtIODevice *vdev,
uint64_t requested_features,
Error **errp)
{
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
/* Firstly sync all virtio-scsi possible supported features */
requested_features |= s->host_features;
return requested_features;
}
static void virtio_scsi_reset(VirtIODevice *vdev)
{
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
assert(!s->dataplane_started);
s->resetting++;
qbus_reset_all(BUS(&s->bus));
s->resetting--;
vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
s->events_dropped = false;
}
void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
uint32_t event, uint32_t reason)
{
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
VirtIOSCSIReq *req;
VirtIOSCSIEvent *evt;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
return;
}
req = virtio_scsi_pop_req(s, vs->event_vq);
if (!req) {
s->events_dropped = true;
return;
}
if (s->events_dropped) {
event |= VIRTIO_SCSI_T_EVENTS_MISSED;
s->events_dropped = false;
}
if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
virtio_scsi_bad_req(req);
return;
}
evt = &req->resp.event;
memset(evt, 0, sizeof(VirtIOSCSIEvent));
evt->event = virtio_tswap32(vdev, event);
evt->reason = virtio_tswap32(vdev, reason);
if (!dev) {
assert(event == VIRTIO_SCSI_T_EVENTS_MISSED);
} else {
evt->lun[0] = 1;
evt->lun[1] = dev->id;
/* Linux wants us to keep the same encoding we use for REPORT LUNS. */
if (dev->lun >= 256) {
evt->lun[2] = (dev->lun >> 8) | 0x40;
}
evt->lun[3] = dev->lun & 0xFF;
}
virtio_scsi_complete_req(req);
}
bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
{
if (s->events_dropped) {
virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
return true;
}
return false;
}
static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
if (s->ctx) {
virtio_device_start_ioeventfd(vdev);
if (!s->dataplane_fenced) {
return;
}
}
virtio_scsi_acquire(s);
virtio_scsi_handle_event_vq(s, vq);
virtio_scsi_release(s);
}
static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
{
VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
VirtIODevice *vdev = VIRTIO_DEVICE(s);
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
dev->type != TYPE_ROM) {
virtio_scsi_acquire(s);
virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
sense.asc | (sense.ascq << 8));
virtio_scsi_release(s);
}
}
static void virtio_scsi_pre_hotplug(HotplugHandler *hotplug_dev,
DeviceState *dev, Error **errp)
{
SCSIDevice *sd = SCSI_DEVICE(dev);
sd->hba_supports_iothread = true;
}
static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
SCSIDevice *sd = SCSI_DEVICE(dev);
int ret;
if (s->ctx && !s->dataplane_fenced) {
if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
return;
}
virtio_scsi_acquire(s);
ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
virtio_scsi_release(s);
if (ret < 0) {
return;
}
}
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
virtio_scsi_acquire(s);
virtio_scsi_push_event(s, sd,
VIRTIO_SCSI_T_TRANSPORT_RESET,
VIRTIO_SCSI_EVT_RESET_RESCAN);
virtio_scsi_release(s);
}
}
static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
SCSIDevice *sd = SCSI_DEVICE(dev);
AioContext *ctx = s->ctx ?: qemu_get_aio_context();
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
virtio_scsi_acquire(s);
virtio_scsi_push_event(s, sd,
VIRTIO_SCSI_T_TRANSPORT_RESET,
VIRTIO_SCSI_EVT_RESET_REMOVED);
virtio_scsi_release(s);
}
aio_disable_external(ctx);
qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
aio_enable_external(ctx);
if (s->ctx) {
virtio_scsi_acquire(s);
/* If other users keep the BlockBackend in the iothread, that's ok */
blk_set_aio_context(sd->conf.blk, qemu_get_aio_context(), NULL);
virtio_scsi_release(s);
}
}
static struct SCSIBusInfo virtio_scsi_scsi_info = {
.tcq = true,
.max_channel = VIRTIO_SCSI_MAX_CHANNEL,
.max_target = VIRTIO_SCSI_MAX_TARGET,
.max_lun = VIRTIO_SCSI_MAX_LUN,
.complete = virtio_scsi_command_complete,
.cancel = virtio_scsi_request_cancelled,
.change = virtio_scsi_change,
.parse_cdb = virtio_scsi_parse_cdb,
.get_sg_list = virtio_scsi_get_sg_list,
.save_request = virtio_scsi_save_request,
.load_request = virtio_scsi_load_request,
};
void virtio_scsi_common_realize(DeviceState *dev,
VirtIOHandleOutput ctrl,
VirtIOHandleOutput evt,
VirtIOHandleOutput cmd,
Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(dev);
int i;
virtio_init(vdev, "virtio-scsi", VIRTIO_ID_SCSI,
sizeof(VirtIOSCSIConfig));
if (s->conf.num_queues == 0 ||
s->conf.num_queues > VIRTIO_QUEUE_MAX - 2) {
error_setg(errp, "Invalid number of queues (= %" PRIu32 "), "
"must be a positive integer less than %d.",
s->conf.num_queues, VIRTIO_QUEUE_MAX - 2);
virtio_cleanup(vdev);
return;
}
if (s->conf.virtqueue_size <= 2) {
error_setg(errp, "invalid virtqueue_size property (= %" PRIu32 "), "
"must be > 2", s->conf.virtqueue_size);
return;
}
s->cmd_vqs = g_new0(VirtQueue *, s->conf.num_queues);
s->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
s->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
s->ctrl_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, ctrl);
s->event_vq = virtio_add_queue(vdev, s->conf.virtqueue_size, evt);
for (i = 0; i < s->conf.num_queues; i++) {
s->cmd_vqs[i] = virtio_add_queue(vdev, s->conf.virtqueue_size, cmd);
}
}
static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOSCSI *s = VIRTIO_SCSI(dev);
Error *err = NULL;
virtio_scsi_common_realize(dev,
virtio_scsi_handle_ctrl,
virtio_scsi_handle_event,
virtio_scsi_handle_cmd,
&err);
if (err != NULL) {
error_propagate(errp, err);
return;
}
scsi_bus_new(&s->bus, sizeof(s->bus), dev,
&virtio_scsi_scsi_info, vdev->bus_name);
/* override default SCSI bus hotplug-handler, with virtio-scsi's one */
qbus_set_hotplug_handler(BUS(&s->bus), OBJECT(dev), &error_abort);
virtio_scsi_dataplane_setup(s, errp);
}
void virtio_scsi_common_unrealize(DeviceState *dev)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
int i;
virtio_delete_queue(vs->ctrl_vq);
virtio_delete_queue(vs->event_vq);
for (i = 0; i < vs->conf.num_queues; i++) {
virtio_delete_queue(vs->cmd_vqs[i]);
}
g_free(vs->cmd_vqs);
virtio_cleanup(vdev);
}
static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
{
VirtIOSCSI *s = VIRTIO_SCSI(dev);
qbus_set_hotplug_handler(BUS(&s->bus), NULL, &error_abort);
virtio_scsi_common_unrealize(dev);
}
static Property virtio_scsi_properties[] = {
DEFINE_PROP_UINT32("num_queues", VirtIOSCSI, parent_obj.conf.num_queues, 1),
DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSI,
parent_obj.conf.virtqueue_size, 256),
DEFINE_PROP_BOOL("seg_max_adjust", VirtIOSCSI,
parent_obj.conf.seg_max_adjust, true),
DEFINE_PROP_UINT32("max_sectors", VirtIOSCSI, parent_obj.conf.max_sectors,
0xFFFF),
DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSI, parent_obj.conf.cmd_per_lun,
128),
DEFINE_PROP_BIT("hotplug", VirtIOSCSI, host_features,
VIRTIO_SCSI_F_HOTPLUG, true),
DEFINE_PROP_BIT("param_change", VirtIOSCSI, host_features,
VIRTIO_SCSI_F_CHANGE, true),
DEFINE_PROP_LINK("iothread", VirtIOSCSI, parent_obj.conf.iothread,
TYPE_IOTHREAD, IOThread *),
DEFINE_PROP_END_OF_LIST(),
};
static const VMStateDescription vmstate_virtio_scsi = {
.name = "virtio-scsi",
.minimum_version_id = 1,
.version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_VIRTIO_DEVICE,
VMSTATE_END_OF_LIST()
},
};
static void virtio_scsi_common_class_init(ObjectClass *klass, void *data)
{
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
vdc->get_config = virtio_scsi_get_config;
set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
}
static void virtio_scsi_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
device_class_set_props(dc, virtio_scsi_properties);
dc->vmsd = &vmstate_virtio_scsi;
set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
vdc->realize = virtio_scsi_device_realize;
vdc->unrealize = virtio_scsi_device_unrealize;
vdc->set_config = virtio_scsi_set_config;
vdc->get_features = virtio_scsi_get_features;
vdc->reset = virtio_scsi_reset;
vdc->start_ioeventfd = virtio_scsi_dataplane_start;
vdc->stop_ioeventfd = virtio_scsi_dataplane_stop;
hc->pre_plug = virtio_scsi_pre_hotplug;
hc->plug = virtio_scsi_hotplug;
hc->unplug = virtio_scsi_hotunplug;
}
static const TypeInfo virtio_scsi_common_info = {
.name = TYPE_VIRTIO_SCSI_COMMON,
.parent = TYPE_VIRTIO_DEVICE,
.instance_size = sizeof(VirtIOSCSICommon),
.abstract = true,
.class_init = virtio_scsi_common_class_init,
};
static const TypeInfo virtio_scsi_info = {
.name = TYPE_VIRTIO_SCSI,
.parent = TYPE_VIRTIO_SCSI_COMMON,
.instance_size = sizeof(VirtIOSCSI),
.class_init = virtio_scsi_class_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_HOTPLUG_HANDLER },
{ }
}
};
static void virtio_register_types(void)
{
type_register_static(&virtio_scsi_common_info);
type_register_static(&virtio_scsi_info);
}
type_init(virtio_register_types)
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