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qemu/hw/block/virtio-blk.c
Marc-André Lureau 26a690c36e hw/virtio-blk: fix -Werror=maybe-uninitialized false-positive 
../hw/block/virtio-blk.c:1212:12: error: ‘rq’ may be used uninitialized [-Werror=maybe-uninitialized]

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2024-10-02 16:14:29 +04:00

2055 lines
66 KiB
C
Raw Blame History

/*
* Virtio Block Device
*
* Copyright IBM, Corp. 2007
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.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 "qemu/defer-call.h"
#include "qapi/error.h"
#include "qemu/iov.h"
#include "qemu/module.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
#include "block/block_int.h"
#include "trace.h"
#include "hw/block/block.h"
#include "hw/qdev-properties.h"
#include "sysemu/blockdev.h"
#include "sysemu/block-ram-registrar.h"
#include "sysemu/sysemu.h"
#include "sysemu/runstate.h"
#include "hw/virtio/virtio-blk.h"
#include "scsi/constants.h"
#ifdef __linux__
# include <scsi/sg.h>
#endif
#include "hw/virtio/virtio-bus.h"
#include "migration/qemu-file-types.h"
#include "hw/virtio/virtio-access.h"
#include "hw/virtio/virtio-blk-common.h"
#include "qemu/coroutine.h"
static void virtio_blk_ioeventfd_attach(VirtIOBlock *s);
static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
VirtIOBlockReq *req)
{
req->dev = s;
req->vq = vq;
req->qiov.size = 0;
req->in_len = 0;
req->next = NULL;
req->mr_next = NULL;
}
static void virtio_blk_free_request(VirtIOBlockReq *req)
{
g_free(req);
}
static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status)
{
VirtIOBlock *s = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
trace_virtio_blk_req_complete(vdev, req, status);
stb_p(&req->in->status, status);
iov_discard_undo(&req->inhdr_undo);
iov_discard_undo(&req->outhdr_undo);
virtqueue_push(req->vq, &req->elem, req->in_len);
if (qemu_in_iothread()) {
virtio_notify_irqfd(vdev, req->vq);
} else {
virtio_notify(vdev, req->vq);
}
}
static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
bool is_read, bool acct_failed)
{
VirtIOBlock *s = req->dev;
BlockErrorAction action = blk_get_error_action(s->blk, is_read, error);
if (action == BLOCK_ERROR_ACTION_STOP) {
/* Break the link as the next request is going to be parsed from the
* ring again. Otherwise we may end up doing a double completion! */
req->mr_next = NULL;
WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
req->next = s->rq;
s->rq = req;
}
} else if (action == BLOCK_ERROR_ACTION_REPORT) {
virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
if (acct_failed) {
block_acct_failed(blk_get_stats(s->blk), &req->acct);
}
virtio_blk_free_request(req);
}
blk_error_action(s->blk, action, is_read, error);
return action != BLOCK_ERROR_ACTION_IGNORE;
}
static void virtio_blk_rw_complete(void *opaque, int ret)
{
VirtIOBlockReq *next = opaque;
VirtIOBlock *s = next->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
while (next) {
VirtIOBlockReq *req = next;
next = req->mr_next;
trace_virtio_blk_rw_complete(vdev, req, ret);
if (req->qiov.nalloc != -1) {
/* If nalloc is != -1 req->qiov is a local copy of the original
* external iovec. It was allocated in submit_requests to be
* able to merge requests. */
qemu_iovec_destroy(&req->qiov);
}
if (ret) {
int p = virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type);
bool is_read = !(p & VIRTIO_BLK_T_OUT);
/* Note that memory may be dirtied on read failure. If the
* virtio request is not completed here, as is the case for
* BLOCK_ERROR_ACTION_STOP, the memory may not be copied
* correctly during live migration. While this is ugly,
* it is acceptable because the device is free to write to
* the memory until the request is completed (which will
* happen on the other side of the migration).
*/
if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) {
continue;
}
}
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
block_acct_done(blk_get_stats(s->blk), &req->acct);
virtio_blk_free_request(req);
}
}
static void virtio_blk_flush_complete(void *opaque, int ret)
{
VirtIOBlockReq *req = opaque;
VirtIOBlock *s = req->dev;
if (ret && virtio_blk_handle_rw_error(req, -ret, 0, true)) {
return;
}
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
block_acct_done(blk_get_stats(s->blk), &req->acct);
virtio_blk_free_request(req);
}
static void virtio_blk_discard_write_zeroes_complete(void *opaque, int ret)
{
VirtIOBlockReq *req = opaque;
VirtIOBlock *s = req->dev;
bool is_write_zeroes = (virtio_ldl_p(VIRTIO_DEVICE(s), &req->out.type) &
~VIRTIO_BLK_T_BARRIER) == VIRTIO_BLK_T_WRITE_ZEROES;
if (ret && virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) {
return;
}
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
if (is_write_zeroes) {
block_acct_done(blk_get_stats(s->blk), &req->acct);
}
virtio_blk_free_request(req);
}
static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s, VirtQueue *vq)
{
VirtIOBlockReq *req = virtqueue_pop(vq, sizeof(VirtIOBlockReq));
if (req) {
virtio_blk_init_request(s, vq, req);
}
return req;
}
static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
{
int status;
struct virtio_scsi_inhdr *scsi;
VirtIOBlock *blk = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(blk);
VirtQueueElement *elem = &req->elem;
/*
* We require at least one output segment each for the virtio_blk_outhdr
* and the SCSI command block.
*
* We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
* and the sense buffer pointer in the input segments.
*/
if (elem->out_num < 2 || elem->in_num < 3) {
status = VIRTIO_BLK_S_IOERR;
goto fail;
}
/*
* The scsi inhdr is placed in the second-to-last input segment, just
* before the regular inhdr.
*
* Just put anything nonzero so that the ioctl fails in the guest.
*/
scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base;
virtio_stl_p(vdev, &scsi->errors, 255);
status = VIRTIO_BLK_S_UNSUPP;
fail:
virtio_blk_req_complete(req, status);
virtio_blk_free_request(req);
}
static inline void submit_requests(VirtIOBlock *s, MultiReqBuffer *mrb,
int start, int num_reqs, int niov)
{
BlockBackend *blk = s->blk;
QEMUIOVector *qiov = &mrb->reqs[start]->qiov;
int64_t sector_num = mrb->reqs[start]->sector_num;
bool is_write = mrb->is_write;
BdrvRequestFlags flags = 0;
if (num_reqs > 1) {
int i;
struct iovec *tmp_iov = qiov->iov;
int tmp_niov = qiov->niov;
/* mrb->reqs[start]->qiov was initialized from external so we can't
* modify it here. We need to initialize it locally and then add the
* external iovecs. */
qemu_iovec_init(qiov, niov);
for (i = 0; i < tmp_niov; i++) {
qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len);
}
for (i = start + 1; i < start + num_reqs; i++) {
qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0,
mrb->reqs[i]->qiov.size);
mrb->reqs[i - 1]->mr_next = mrb->reqs[i];
}
trace_virtio_blk_submit_multireq(VIRTIO_DEVICE(mrb->reqs[start]->dev),
mrb, start, num_reqs,
sector_num << BDRV_SECTOR_BITS,
qiov->size, is_write);
block_acct_merge_done(blk_get_stats(blk),
is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ,
num_reqs - 1);
}
if (blk_ram_registrar_ok(&s->blk_ram_registrar)) {
flags |= BDRV_REQ_REGISTERED_BUF;
}
if (is_write) {
blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov,
flags, virtio_blk_rw_complete,
mrb->reqs[start]);
} else {
blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov,
flags, virtio_blk_rw_complete,
mrb->reqs[start]);
}
}
static int multireq_compare(const void *a, const void *b)
{
const VirtIOBlockReq *req1 = *(VirtIOBlockReq **)a,
*req2 = *(VirtIOBlockReq **)b;
/*
* Note that we can't simply subtract sector_num1 from sector_num2
* here as that could overflow the return value.
*/
if (req1->sector_num > req2->sector_num) {
return 1;
} else if (req1->sector_num < req2->sector_num) {
return -1;
} else {
return 0;
}
}
static void virtio_blk_submit_multireq(VirtIOBlock *s, MultiReqBuffer *mrb)
{
int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0;
uint32_t max_transfer;
int64_t sector_num = 0;
if (mrb->num_reqs == 1) {
submit_requests(s, mrb, 0, 1, -1);
mrb->num_reqs = 0;
return;
}
max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk);
qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs),
&multireq_compare);
for (i = 0; i < mrb->num_reqs; i++) {
VirtIOBlockReq *req = mrb->reqs[i];
if (num_reqs > 0) {
/*
* NOTE: We cannot merge the requests in below situations:
* 1. requests are not sequential
* 2. merge would exceed maximum number of IOVs
* 3. merge would exceed maximum transfer length of backend device
*/
if (sector_num + nb_sectors != req->sector_num ||
niov > blk_get_max_iov(s->blk) - req->qiov.niov ||
req->qiov.size > max_transfer ||
nb_sectors > (max_transfer -
req->qiov.size) / BDRV_SECTOR_SIZE) {
submit_requests(s, mrb, start, num_reqs, niov);
num_reqs = 0;
}
}
if (num_reqs == 0) {
sector_num = req->sector_num;
nb_sectors = niov = 0;
start = i;
}
nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE;
niov += req->qiov.niov;
num_reqs++;
}
submit_requests(s, mrb, start, num_reqs, niov);
mrb->num_reqs = 0;
}
static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb)
{
VirtIOBlock *s = req->dev;
block_acct_start(blk_get_stats(s->blk), &req->acct, 0,
BLOCK_ACCT_FLUSH);
/*
* Make sure all outstanding writes are posted to the backing device.
*/
if (mrb->is_write && mrb->num_reqs > 0) {
virtio_blk_submit_multireq(s, mrb);
}
blk_aio_flush(s->blk, virtio_blk_flush_complete, req);
}
static bool virtio_blk_sect_range_ok(VirtIOBlock *dev,
uint64_t sector, size_t size)
{
uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
uint64_t total_sectors;
if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
return false;
}
if (sector & dev->sector_mask) {
return false;
}
if (size % dev->conf.conf.logical_block_size) {
return false;
}
blk_get_geometry(dev->blk, &total_sectors);
if (sector > total_sectors || nb_sectors > total_sectors - sector) {
return false;
}
return true;
}
static uint8_t virtio_blk_handle_discard_write_zeroes(VirtIOBlockReq *req,
struct virtio_blk_discard_write_zeroes *dwz_hdr, bool is_write_zeroes)
{
VirtIOBlock *s = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
uint64_t sector;
uint32_t num_sectors, flags, max_sectors;
uint8_t err_status;
int bytes;
sector = virtio_ldq_p(vdev, &dwz_hdr->sector);
num_sectors = virtio_ldl_p(vdev, &dwz_hdr->num_sectors);
flags = virtio_ldl_p(vdev, &dwz_hdr->flags);
max_sectors = is_write_zeroes ? s->conf.max_write_zeroes_sectors :
s->conf.max_discard_sectors;
/*
* max_sectors is at most BDRV_REQUEST_MAX_SECTORS, this check
* make us sure that "num_sectors << BDRV_SECTOR_BITS" can fit in
* the integer variable.
*/
if (unlikely(num_sectors > max_sectors)) {
err_status = VIRTIO_BLK_S_IOERR;
goto err;
}
bytes = num_sectors << BDRV_SECTOR_BITS;
if (unlikely(!virtio_blk_sect_range_ok(s, sector, bytes))) {
err_status = VIRTIO_BLK_S_IOERR;
goto err;
}
/*
* The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard
* and write zeroes commands if any unknown flag is set.
*/
if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
err_status = VIRTIO_BLK_S_UNSUPP;
goto err;
}
if (is_write_zeroes) { /* VIRTIO_BLK_T_WRITE_ZEROES */
int blk_aio_flags = 0;
if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {
blk_aio_flags |= BDRV_REQ_MAY_UNMAP;
}
block_acct_start(blk_get_stats(s->blk), &req->acct, bytes,
BLOCK_ACCT_WRITE);
blk_aio_pwrite_zeroes(s->blk, sector << BDRV_SECTOR_BITS,
bytes, blk_aio_flags,
virtio_blk_discard_write_zeroes_complete, req);
} else { /* VIRTIO_BLK_T_DISCARD */
/*
* The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for
* discard commands if the unmap flag is set.
*/
if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) {
err_status = VIRTIO_BLK_S_UNSUPP;
goto err;
}
blk_aio_pdiscard(s->blk, sector << BDRV_SECTOR_BITS, bytes,
virtio_blk_discard_write_zeroes_complete, req);
}
return VIRTIO_BLK_S_OK;
err:
if (is_write_zeroes) {
block_acct_invalid(blk_get_stats(s->blk), BLOCK_ACCT_WRITE);
}
return err_status;
}
typedef struct ZoneCmdData {
VirtIOBlockReq *req;
struct iovec *in_iov;
unsigned in_num;
union {
struct {
unsigned int nr_zones;
BlockZoneDescriptor *zones;
} zone_report_data;
struct {
int64_t offset;
} zone_append_data;
};
} ZoneCmdData;
/*
* check zoned_request: error checking before issuing requests. If all checks
* passed, return true.
* append: true if only zone append requests issued.
*/
static bool check_zoned_request(VirtIOBlock *s, int64_t offset, int64_t len,
bool append, uint8_t *status) {
BlockDriverState *bs = blk_bs(s->blk);
int index;
if (!virtio_has_feature(s->host_features, VIRTIO_BLK_F_ZONED)) {
*status = VIRTIO_BLK_S_UNSUPP;
return false;
}
if (offset < 0 || len < 0 || len > (bs->total_sectors << BDRV_SECTOR_BITS)
|| offset > (bs->total_sectors << BDRV_SECTOR_BITS) - len) {
*status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
return false;
}
if (append) {
if (bs->bl.write_granularity) {
if ((offset % bs->bl.write_granularity) != 0) {
*status = VIRTIO_BLK_S_ZONE_UNALIGNED_WP;
return false;
}
}
index = offset / bs->bl.zone_size;
if (BDRV_ZT_IS_CONV(bs->wps->wp[index])) {
*status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
return false;
}
if (len / 512 > bs->bl.max_append_sectors) {
if (bs->bl.max_append_sectors == 0) {
*status = VIRTIO_BLK_S_UNSUPP;
} else {
*status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
}
return false;
}
}
return true;
}
static void virtio_blk_zone_report_complete(void *opaque, int ret)
{
ZoneCmdData *data = opaque;
VirtIOBlockReq *req = data->req;
VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
struct iovec *in_iov = data->in_iov;
unsigned in_num = data->in_num;
int64_t zrp_size, n, j = 0;
int64_t nz = data->zone_report_data.nr_zones;
int8_t err_status = VIRTIO_BLK_S_OK;
struct virtio_blk_zone_report zrp_hdr = (struct virtio_blk_zone_report) {
.nr_zones = cpu_to_le64(nz),
};
trace_virtio_blk_zone_report_complete(vdev, req, nz, ret);
if (ret) {
err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
goto out;
}
zrp_size = sizeof(struct virtio_blk_zone_report)
+ sizeof(struct virtio_blk_zone_descriptor) * nz;
n = iov_from_buf(in_iov, in_num, 0, &zrp_hdr, sizeof(zrp_hdr));
if (n != sizeof(zrp_hdr)) {
virtio_error(vdev, "Driver provided input buffer that is too small!");
err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
goto out;
}
for (size_t i = sizeof(zrp_hdr); i < zrp_size;
i += sizeof(struct virtio_blk_zone_descriptor), ++j) {
struct virtio_blk_zone_descriptor desc =
(struct virtio_blk_zone_descriptor) {
.z_start = cpu_to_le64(data->zone_report_data.zones[j].start
>> BDRV_SECTOR_BITS),
.z_cap = cpu_to_le64(data->zone_report_data.zones[j].cap
>> BDRV_SECTOR_BITS),
.z_wp = cpu_to_le64(data->zone_report_data.zones[j].wp
>> BDRV_SECTOR_BITS),
};
switch (data->zone_report_data.zones[j].type) {
case BLK_ZT_CONV:
desc.z_type = VIRTIO_BLK_ZT_CONV;
break;
case BLK_ZT_SWR:
desc.z_type = VIRTIO_BLK_ZT_SWR;
break;
case BLK_ZT_SWP:
desc.z_type = VIRTIO_BLK_ZT_SWP;
break;
default:
g_assert_not_reached();
}
switch (data->zone_report_data.zones[j].state) {
case BLK_ZS_RDONLY:
desc.z_state = VIRTIO_BLK_ZS_RDONLY;
break;
case BLK_ZS_OFFLINE:
desc.z_state = VIRTIO_BLK_ZS_OFFLINE;
break;
case BLK_ZS_EMPTY:
desc.z_state = VIRTIO_BLK_ZS_EMPTY;
break;
case BLK_ZS_CLOSED:
desc.z_state = VIRTIO_BLK_ZS_CLOSED;
break;
case BLK_ZS_FULL:
desc.z_state = VIRTIO_BLK_ZS_FULL;
break;
case BLK_ZS_EOPEN:
desc.z_state = VIRTIO_BLK_ZS_EOPEN;
break;
case BLK_ZS_IOPEN:
desc.z_state = VIRTIO_BLK_ZS_IOPEN;
break;
case BLK_ZS_NOT_WP:
desc.z_state = VIRTIO_BLK_ZS_NOT_WP;
break;
default:
g_assert_not_reached();
}
/* TODO: it takes O(n^2) time complexity. Optimizations required. */
n = iov_from_buf(in_iov, in_num, i, &desc, sizeof(desc));
if (n != sizeof(desc)) {
virtio_error(vdev, "Driver provided input buffer "
"for descriptors that is too small!");
err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
}
}
out:
virtio_blk_req_complete(req, err_status);
virtio_blk_free_request(req);
g_free(data->zone_report_data.zones);
g_free(data);
}
static void virtio_blk_handle_zone_report(VirtIOBlockReq *req,
struct iovec *in_iov,
unsigned in_num)
{
VirtIOBlock *s = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
unsigned int nr_zones;
ZoneCmdData *data;
int64_t zone_size, offset;
uint8_t err_status;
if (req->in_len < sizeof(struct virtio_blk_inhdr) +
sizeof(struct virtio_blk_zone_report) +
sizeof(struct virtio_blk_zone_descriptor)) {
virtio_error(vdev, "in buffer too small for zone report");
err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
goto out;
}
/* start byte offset of the zone report */
offset = virtio_ldq_p(vdev, &req->out.sector) << BDRV_SECTOR_BITS;
if (!check_zoned_request(s, offset, 0, false, &err_status)) {
goto out;
}
nr_zones = (req->in_len - sizeof(struct virtio_blk_inhdr) -
sizeof(struct virtio_blk_zone_report)) /
sizeof(struct virtio_blk_zone_descriptor);
trace_virtio_blk_handle_zone_report(vdev, req,
offset >> BDRV_SECTOR_BITS, nr_zones);
zone_size = sizeof(BlockZoneDescriptor) * nr_zones;
data = g_malloc(sizeof(ZoneCmdData));
data->req = req;
data->in_iov = in_iov;
data->in_num = in_num;
data->zone_report_data.nr_zones = nr_zones;
data->zone_report_data.zones = g_malloc(zone_size),
blk_aio_zone_report(s->blk, offset, &data->zone_report_data.nr_zones,
data->zone_report_data.zones,
virtio_blk_zone_report_complete, data);
return;
out:
virtio_blk_req_complete(req, err_status);
virtio_blk_free_request(req);
}
static void virtio_blk_zone_mgmt_complete(void *opaque, int ret)
{
VirtIOBlockReq *req = opaque;
VirtIOBlock *s = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
int8_t err_status = VIRTIO_BLK_S_OK;
trace_virtio_blk_zone_mgmt_complete(vdev, req,ret);
if (ret) {
err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
}
virtio_blk_req_complete(req, err_status);
virtio_blk_free_request(req);
}
static int virtio_blk_handle_zone_mgmt(VirtIOBlockReq *req, BlockZoneOp op)
{
VirtIOBlock *s = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
BlockDriverState *bs = blk_bs(s->blk);
int64_t offset = virtio_ldq_p(vdev, &req->out.sector) << BDRV_SECTOR_BITS;
uint64_t len;
uint64_t capacity = bs->total_sectors << BDRV_SECTOR_BITS;
uint8_t err_status = VIRTIO_BLK_S_OK;
uint32_t type = virtio_ldl_p(vdev, &req->out.type);
if (type == VIRTIO_BLK_T_ZONE_RESET_ALL) {
/* Entire drive capacity */
offset = 0;
len = capacity;
trace_virtio_blk_handle_zone_reset_all(vdev, req, 0,
bs->total_sectors);
} else {
if (bs->bl.zone_size > capacity - offset) {
/* The zoned device allows the last smaller zone. */
len = capacity - bs->bl.zone_size * (bs->bl.nr_zones - 1ull);
} else {
len = bs->bl.zone_size;
}
trace_virtio_blk_handle_zone_mgmt(vdev, req, op,
offset >> BDRV_SECTOR_BITS,
len >> BDRV_SECTOR_BITS);
}
if (!check_zoned_request(s, offset, len, false, &err_status)) {
goto out;
}
blk_aio_zone_mgmt(s->blk, op, offset, len,
virtio_blk_zone_mgmt_complete, req);
return 0;
out:
virtio_blk_req_complete(req, err_status);
virtio_blk_free_request(req);
return err_status;
}
static void virtio_blk_zone_append_complete(void *opaque, int ret)
{
ZoneCmdData *data = opaque;
VirtIOBlockReq *req = data->req;
VirtIODevice *vdev = VIRTIO_DEVICE(req->dev);
int64_t append_sector, n;
uint8_t err_status = VIRTIO_BLK_S_OK;
if (ret) {
err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
goto out;
}
virtio_stq_p(vdev, &append_sector,
data->zone_append_data.offset >> BDRV_SECTOR_BITS);
n = iov_from_buf(data->in_iov, data->in_num, 0, &append_sector,
sizeof(append_sector));
if (n != sizeof(append_sector)) {
virtio_error(vdev, "Driver provided input buffer less than size of "
"append_sector");
err_status = VIRTIO_BLK_S_ZONE_INVALID_CMD;
goto out;
}
trace_virtio_blk_zone_append_complete(vdev, req, append_sector, ret);
out:
virtio_blk_req_complete(req, err_status);
virtio_blk_free_request(req);
g_free(data);
}
static int virtio_blk_handle_zone_append(VirtIOBlockReq *req,
struct iovec *out_iov,
struct iovec *in_iov,
uint64_t out_num,
unsigned in_num) {
VirtIOBlock *s = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
uint8_t err_status = VIRTIO_BLK_S_OK;
int64_t offset = virtio_ldq_p(vdev, &req->out.sector) << BDRV_SECTOR_BITS;
int64_t len = iov_size(out_iov, out_num);
ZoneCmdData *data;
trace_virtio_blk_handle_zone_append(vdev, req, offset >> BDRV_SECTOR_BITS);
if (!check_zoned_request(s, offset, len, true, &err_status)) {
goto out;
}
data = g_malloc(sizeof(ZoneCmdData));
data->req = req;
data->in_iov = in_iov;
data->in_num = in_num;
data->zone_append_data.offset = offset;
qemu_iovec_init_external(&req->qiov, out_iov, out_num);
block_acct_start(blk_get_stats(s->blk), &req->acct, len,
BLOCK_ACCT_ZONE_APPEND);
blk_aio_zone_append(s->blk, &data->zone_append_data.offset, &req->qiov, 0,
virtio_blk_zone_append_complete, data);
return 0;
out:
virtio_blk_req_complete(req, err_status);
virtio_blk_free_request(req);
return err_status;
}
static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb)
{
uint32_t type;
struct iovec *in_iov = req->elem.in_sg;
struct iovec *out_iov = req->elem.out_sg;
unsigned in_num = req->elem.in_num;
unsigned out_num = req->elem.out_num;
VirtIOBlock *s = req->dev;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
if (req->elem.out_num < 1 || req->elem.in_num < 1) {
virtio_error(vdev, "virtio-blk missing headers");
return -1;
}
if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out,
sizeof(req->out)) != sizeof(req->out))) {
virtio_error(vdev, "virtio-blk request outhdr too short");
return -1;
}
iov_discard_front_undoable(&out_iov, &out_num, sizeof(req->out),
&req->outhdr_undo);
if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
virtio_error(vdev, "virtio-blk request inhdr too short");
iov_discard_undo(&req->outhdr_undo);
return -1;
}
/* We always touch the last byte, so just see how big in_iov is. */
req->in_len = iov_size(in_iov, in_num);
req->in = (void *)in_iov[in_num - 1].iov_base
+ in_iov[in_num - 1].iov_len
- sizeof(struct virtio_blk_inhdr);
iov_discard_back_undoable(in_iov, &in_num, sizeof(struct virtio_blk_inhdr),
&req->inhdr_undo);
type = virtio_ldl_p(vdev, &req->out.type);
/* VIRTIO_BLK_T_OUT defines the command direction. VIRTIO_BLK_T_BARRIER
* is an optional flag. Although a guest should not send this flag if
* not negotiated we ignored it in the past. So keep ignoring it. */
switch (type & ~(VIRTIO_BLK_T_OUT | VIRTIO_BLK_T_BARRIER)) {
case VIRTIO_BLK_T_IN:
{
bool is_write = type & VIRTIO_BLK_T_OUT;
req->sector_num = virtio_ldq_p(vdev, &req->out.sector);
if (is_write) {
qemu_iovec_init_external(&req->qiov, out_iov, out_num);
trace_virtio_blk_handle_write(vdev, req, req->sector_num,
req->qiov.size / BDRV_SECTOR_SIZE);
} else {
qemu_iovec_init_external(&req->qiov, in_iov, in_num);
trace_virtio_blk_handle_read(vdev, req, req->sector_num,
req->qiov.size / BDRV_SECTOR_SIZE);
}
if (!virtio_blk_sect_range_ok(s, req->sector_num, req->qiov.size)) {
virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
block_acct_invalid(blk_get_stats(s->blk),
is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
virtio_blk_free_request(req);
return 0;
}
block_acct_start(blk_get_stats(s->blk), &req->acct, req->qiov.size,
is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
/* merge would exceed maximum number of requests or IO direction
* changes */
if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS ||
is_write != mrb->is_write ||
!s->conf.request_merging)) {
virtio_blk_submit_multireq(s, mrb);
}
assert(mrb->num_reqs < VIRTIO_BLK_MAX_MERGE_REQS);
mrb->reqs[mrb->num_reqs++] = req;
mrb->is_write = is_write;
break;
}
case VIRTIO_BLK_T_FLUSH:
virtio_blk_handle_flush(req, mrb);
break;
case VIRTIO_BLK_T_ZONE_REPORT:
virtio_blk_handle_zone_report(req, in_iov, in_num);
break;
case VIRTIO_BLK_T_ZONE_OPEN:
virtio_blk_handle_zone_mgmt(req, BLK_ZO_OPEN);
break;
case VIRTIO_BLK_T_ZONE_CLOSE:
virtio_blk_handle_zone_mgmt(req, BLK_ZO_CLOSE);
break;
case VIRTIO_BLK_T_ZONE_FINISH:
virtio_blk_handle_zone_mgmt(req, BLK_ZO_FINISH);
break;
case VIRTIO_BLK_T_ZONE_RESET:
virtio_blk_handle_zone_mgmt(req, BLK_ZO_RESET);
break;
case VIRTIO_BLK_T_ZONE_RESET_ALL:
virtio_blk_handle_zone_mgmt(req, BLK_ZO_RESET);
break;
case VIRTIO_BLK_T_SCSI_CMD:
virtio_blk_handle_scsi(req);
break;
case VIRTIO_BLK_T_GET_ID:
{
/*
* NB: per existing s/n string convention the string is
* terminated by '\0' only when shorter than buffer.
*/
const char *serial = s->conf.serial ? s->conf.serial : "";
size_t size = MIN(strlen(serial) + 1,
MIN(iov_size(in_iov, in_num),
VIRTIO_BLK_ID_BYTES));
iov_from_buf(in_iov, in_num, 0, serial, size);
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
virtio_blk_free_request(req);
break;
}
case VIRTIO_BLK_T_ZONE_APPEND & ~VIRTIO_BLK_T_OUT:
/*
* Passing out_iov/out_num and in_iov/in_num is not safe
* to access req->elem.out_sg directly because it may be
* modified by virtio_blk_handle_request().
*/
virtio_blk_handle_zone_append(req, out_iov, in_iov, out_num, in_num);
break;
/*
* VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES are defined with
* VIRTIO_BLK_T_OUT flag set. We masked this flag in the switch statement,
* so we must mask it for these requests, then we will check if it is set.
*/
case VIRTIO_BLK_T_DISCARD & ~VIRTIO_BLK_T_OUT:
case VIRTIO_BLK_T_WRITE_ZEROES & ~VIRTIO_BLK_T_OUT:
{
struct virtio_blk_discard_write_zeroes dwz_hdr;
size_t out_len = iov_size(out_iov, out_num);
bool is_write_zeroes = (type & ~VIRTIO_BLK_T_BARRIER) ==
VIRTIO_BLK_T_WRITE_ZEROES;
uint8_t err_status;
/*
* Unsupported if VIRTIO_BLK_T_OUT is not set or the request contains
* more than one segment.
*/
if (unlikely(!(type & VIRTIO_BLK_T_OUT) ||
out_len > sizeof(dwz_hdr))) {
virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
virtio_blk_free_request(req);
return 0;
}
if (unlikely(iov_to_buf(out_iov, out_num, 0, &dwz_hdr,
sizeof(dwz_hdr)) != sizeof(dwz_hdr))) {
iov_discard_undo(&req->inhdr_undo);
iov_discard_undo(&req->outhdr_undo);
virtio_error(vdev, "virtio-blk discard/write_zeroes header"
" too short");
return -1;
}
err_status = virtio_blk_handle_discard_write_zeroes(req, &dwz_hdr,
is_write_zeroes);
if (err_status != VIRTIO_BLK_S_OK) {
virtio_blk_req_complete(req, err_status);
virtio_blk_free_request(req);
}
break;
}
default:
virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
virtio_blk_free_request(req);
}
return 0;
}
void virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq)
{
VirtIOBlockReq *req;
MultiReqBuffer mrb = {};
bool suppress_notifications = virtio_queue_get_notification(vq);
defer_call_begin();
do {
if (suppress_notifications) {
virtio_queue_set_notification(vq, 0);
}
while ((req = virtio_blk_get_request(s, vq))) {
if (virtio_blk_handle_request(req, &mrb)) {
virtqueue_detach_element(req->vq, &req->elem, 0);
virtio_blk_free_request(req);
break;
}
}
if (suppress_notifications) {
virtio_queue_set_notification(vq, 1);
}
} while (!virtio_queue_empty(vq));
if (mrb.num_reqs) {
virtio_blk_submit_multireq(s, &mrb);
}
defer_call_end();
}
static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOBlock *s = (VirtIOBlock *)vdev;
if (!s->ioeventfd_disabled && !s->ioeventfd_started) {
/* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
* ioeventfd here instead of waiting for .set_status().
*/
virtio_device_start_ioeventfd(vdev);
if (!s->ioeventfd_disabled) {
return;
}
}
virtio_blk_handle_vq(s, vq);
}
static void virtio_blk_dma_restart_bh(void *opaque)
{
VirtIOBlockReq *req = opaque;
VirtIOBlock *s = req->dev; /* we're called with at least one request */
MultiReqBuffer mrb = {};
while (req) {
VirtIOBlockReq *next = req->next;
if (virtio_blk_handle_request(req, &mrb)) {
/* Device is now broken and won't do any processing until it gets
* reset. Already queued requests will be lost: let's purge them.
*/
while (req) {
next = req->next;
virtqueue_detach_element(req->vq, &req->elem, 0);
virtio_blk_free_request(req);
req = next;
}
break;
}
req = next;
}
if (mrb.num_reqs) {
virtio_blk_submit_multireq(s, &mrb);
}
/* Paired with inc in virtio_blk_dma_restart_cb() */
blk_dec_in_flight(s->conf.conf.blk);
}
static void virtio_blk_dma_restart_cb(void *opaque, bool running,
RunState state)
{
VirtIOBlock *s = opaque;
uint16_t num_queues = s->conf.num_queues;
g_autofree VirtIOBlockReq **vq_rq = NULL;
VirtIOBlockReq *rq = NULL;
if (!running) {
return;
}
/* Split the device-wide s->rq request list into per-vq request lists */
vq_rq = g_new0(VirtIOBlockReq *, num_queues);
WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
rq = s->rq;
s->rq = NULL;
}
while (rq) {
VirtIOBlockReq *next = rq->next;
uint16_t idx = virtio_get_queue_index(rq->vq);
/* Only num_queues vqs were created so vq_rq[idx] is within bounds */
assert(idx < num_queues);
rq->next = vq_rq[idx];
vq_rq[idx] = rq;
rq = next;
}
/* Schedule a BH to submit the requests in each vq's AioContext */
for (uint16_t i = 0; i < num_queues; i++) {
if (!vq_rq[i]) {
continue;
}
/* Paired with dec in virtio_blk_dma_restart_bh() */
blk_inc_in_flight(s->conf.conf.blk);
aio_bh_schedule_oneshot(s->vq_aio_context[i],
virtio_blk_dma_restart_bh,
vq_rq[i]);
}
}
static void virtio_blk_reset(VirtIODevice *vdev)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
VirtIOBlockReq *req;
/* Dataplane has stopped... */
assert(!s->ioeventfd_started);
/* ...but requests may still be in flight. */
blk_drain(s->blk);
/* We drop queued requests after blk_drain() because blk_drain() itself can
* produce them. */
WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
while (s->rq) {
req = s->rq;
s->rq = req->next;
/* No other threads can access req->vq here */
virtqueue_detach_element(req->vq, &req->elem, 0);
virtio_blk_free_request(req);
}
}
blk_set_enable_write_cache(s->blk, s->original_wce);
}
/* coalesce internal state, copy to pci i/o region 0
*/
static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
BlockConf *conf = &s->conf.conf;
BlockDriverState *bs = blk_bs(s->blk);
struct virtio_blk_config blkcfg;
uint64_t capacity;
int64_t length;
int blk_size = conf->logical_block_size;
blk_get_geometry(s->blk, &capacity);
memset(&blkcfg, 0, sizeof(blkcfg));
virtio_stq_p(vdev, &blkcfg.capacity, capacity);
virtio_stl_p(vdev, &blkcfg.seg_max,
s->conf.seg_max_adjust ? s->conf.queue_size - 2 : 128 - 2);
virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls);
virtio_stl_p(vdev, &blkcfg.blk_size, blk_size);
virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size);
virtio_stl_p(vdev, &blkcfg.opt_io_size, conf->opt_io_size / blk_size);
blkcfg.geometry.heads = conf->heads;
/*
* We must ensure that the block device capacity is a multiple of
* the logical block size. If that is not the case, let's use
* sector_mask to adopt the geometry to have a correct picture.
* For those devices where the capacity is ok for the given geometry
* we don't touch the sector value of the geometry, since some devices
* (like s390 dasd) need a specific value. Here the capacity is already
* cyls*heads*secs*blk_size and the sector value is not block size
* divided by 512 - instead it is the amount of blk_size blocks
* per track (cylinder).
*/
length = blk_getlength(s->blk);
if (length > 0 && length / conf->heads / conf->secs % blk_size) {
blkcfg.geometry.sectors = conf->secs & ~s->sector_mask;
} else {
blkcfg.geometry.sectors = conf->secs;
}
blkcfg.size_max = 0;
blkcfg.physical_block_exp = get_physical_block_exp(conf);
blkcfg.alignment_offset = 0;
blkcfg.wce = blk_enable_write_cache(s->blk);
virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues);
if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) {
uint32_t discard_granularity = conf->discard_granularity;
if (discard_granularity == -1 || !s->conf.report_discard_granularity) {
discard_granularity = blk_size;
}
virtio_stl_p(vdev, &blkcfg.max_discard_sectors,
s->conf.max_discard_sectors);
virtio_stl_p(vdev, &blkcfg.discard_sector_alignment,
discard_granularity >> BDRV_SECTOR_BITS);
/*
* We support only one segment per request since multiple segments
* are not widely used and there are no userspace APIs that allow
* applications to submit multiple segments in a single call.
*/
virtio_stl_p(vdev, &blkcfg.max_discard_seg, 1);
}
if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES)) {
virtio_stl_p(vdev, &blkcfg.max_write_zeroes_sectors,
s->conf.max_write_zeroes_sectors);
blkcfg.write_zeroes_may_unmap = 1;
virtio_stl_p(vdev, &blkcfg.max_write_zeroes_seg, 1);
}
if (bs->bl.zoned != BLK_Z_NONE) {
switch (bs->bl.zoned) {
case BLK_Z_HM:
blkcfg.zoned.model = VIRTIO_BLK_Z_HM;
break;
case BLK_Z_HA:
blkcfg.zoned.model = VIRTIO_BLK_Z_HA;
break;
default:
g_assert_not_reached();
}
virtio_stl_p(vdev, &blkcfg.zoned.zone_sectors,
bs->bl.zone_size / 512);
virtio_stl_p(vdev, &blkcfg.zoned.max_active_zones,
bs->bl.max_active_zones);
virtio_stl_p(vdev, &blkcfg.zoned.max_open_zones,
bs->bl.max_open_zones);
virtio_stl_p(vdev, &blkcfg.zoned.write_granularity, blk_size);
virtio_stl_p(vdev, &blkcfg.zoned.max_append_sectors,
bs->bl.max_append_sectors);
} else {
blkcfg.zoned.model = VIRTIO_BLK_Z_NONE;
}
memcpy(config, &blkcfg, s->config_size);
}
static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
struct virtio_blk_config blkcfg;
memcpy(&blkcfg, config, s->config_size);
blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
}
static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features,
Error **errp)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
/* Firstly sync all virtio-blk possible supported features */
features |= s->host_features;
virtio_add_feature(&features, VIRTIO_BLK_F_SEG_MAX);
virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
if (!virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
/* Added for historical reasons, removing it could break migration. */
virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
}
if (blk_enable_write_cache(s->blk) ||
(s->conf.x_enable_wce_if_config_wce &&
virtio_has_feature(features, VIRTIO_BLK_F_CONFIG_WCE))) {
virtio_add_feature(&features, VIRTIO_BLK_F_WCE);
}
if (!blk_is_writable(s->blk)) {
virtio_add_feature(&features, VIRTIO_BLK_F_RO);
}
if (s->conf.num_queues > 1) {
virtio_add_feature(&features, VIRTIO_BLK_F_MQ);
}
return features;
}
static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
if (!(status & (VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK))) {
assert(!s->ioeventfd_started);
}
if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
return;
}
/* A guest that supports VIRTIO_BLK_F_CONFIG_WCE must be able to send
* cache flushes. Thus, the "auto writethrough" behavior is never
* necessary for guests that support the VIRTIO_BLK_F_CONFIG_WCE feature.
* Leaving it enabled would break the following sequence:
*
* Guest started with "-drive cache=writethrough"
* Guest sets status to 0
* Guest sets DRIVER bit in status field
* Guest reads host features (WCE=0, CONFIG_WCE=1)
* Guest writes guest features (WCE=0, CONFIG_WCE=1)
* Guest writes 1 to the WCE configuration field (writeback mode)
* Guest sets DRIVER_OK bit in status field
*
* s->blk would erroneously be placed in writethrough mode.
*/
if (!virtio_vdev_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) {
blk_set_enable_write_cache(s->blk,
virtio_vdev_has_feature(vdev,
VIRTIO_BLK_F_WCE));
}
}
static void virtio_blk_save_device(VirtIODevice *vdev, QEMUFile *f)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
VirtIOBlockReq *req = s->rq;
while (req) {
qemu_put_sbyte(f, 1);
if (s->conf.num_queues > 1) {
qemu_put_be32(f, virtio_get_queue_index(req->vq));
}
qemu_put_virtqueue_element(vdev, f, &req->elem);
req = req->next;
}
}
qemu_put_sbyte(f, 0);
}
static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f,
int version_id)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
while (qemu_get_sbyte(f)) {
unsigned nvqs = s->conf.num_queues;
unsigned vq_idx = 0;
VirtIOBlockReq *req;
if (nvqs > 1) {
vq_idx = qemu_get_be32(f);
if (vq_idx >= nvqs) {
error_report("Invalid virtqueue index in request list: %#x",
vq_idx);
return -EINVAL;
}
}
req = qemu_get_virtqueue_element(vdev, f, sizeof(VirtIOBlockReq));
virtio_blk_init_request(s, virtio_get_queue(vdev, vq_idx), req);
WITH_QEMU_LOCK_GUARD(&s->rq_lock) {
req->next = s->rq;
s->rq = req;
}
}
return 0;
}
static void virtio_resize_cb(void *opaque)
{
VirtIODevice *vdev = opaque;
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
virtio_notify_config(vdev);
}
static void virtio_blk_resize(void *opaque)
{
VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
/*
* virtio_notify_config() needs to acquire the BQL,
* so it can't be called from an iothread. Instead, schedule
* it to be run in the main context BH.
*/
aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev);
}
static void virtio_blk_ioeventfd_detach(VirtIOBlock *s)
{
VirtIODevice *vdev = VIRTIO_DEVICE(s);
for (uint16_t i = 0; i < s->conf.num_queues; i++) {
VirtQueue *vq = virtio_get_queue(vdev, i);
virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]);
}
}
static void virtio_blk_ioeventfd_attach(VirtIOBlock *s)
{
VirtIODevice *vdev = VIRTIO_DEVICE(s);
for (uint16_t i = 0; i < s->conf.num_queues; i++) {
VirtQueue *vq = virtio_get_queue(vdev, i);
virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]);
}
}
/* Suspend virtqueue ioeventfd processing during drain */
static void virtio_blk_drained_begin(void *opaque)
{
VirtIOBlock *s = opaque;
if (s->ioeventfd_started) {
virtio_blk_ioeventfd_detach(s);
}
}
/* Resume virtqueue ioeventfd processing after drain */
static void virtio_blk_drained_end(void *opaque)
{
VirtIOBlock *s = opaque;
if (s->ioeventfd_started) {
virtio_blk_ioeventfd_attach(s);
}
}
static const BlockDevOps virtio_block_ops = {
.resize_cb = virtio_blk_resize,
.drained_begin = virtio_blk_drained_begin,
.drained_end = virtio_blk_drained_end,
};
static bool
validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list,
uint16_t num_queues, Error **errp)
{
g_autofree unsigned long *vqs = bitmap_new(num_queues);
g_autoptr(GHashTable) iothreads =
g_hash_table_new(g_str_hash, g_str_equal);
for (IOThreadVirtQueueMappingList *node = list; node; node = node->next) {
const char *name = node->value->iothread;
uint16List *vq;
if (!iothread_by_id(name)) {
error_setg(errp, "IOThread \"%s\" object does not exist", name);
return false;
}
if (!g_hash_table_add(iothreads, (gpointer)name)) {
error_setg(errp,
"duplicate IOThread name \"%s\" in iothread-vq-mapping",
name);
return false;
}
if (node != list) {
if (!!node->value->vqs != !!list->value->vqs) {
error_setg(errp, "either all items in iothread-vq-mapping "
"must have vqs or none of them must have it");
return false;
}
}
for (vq = node->value->vqs; vq; vq = vq->next) {
if (vq->value >= num_queues) {
error_setg(errp, "vq index %u for IOThread \"%s\" must be "
"less than num_queues %u in iothread-vq-mapping",
vq->value, name, num_queues);
return false;
}
if (test_and_set_bit(vq->value, vqs)) {
error_setg(errp, "cannot assign vq %u to IOThread \"%s\" "
"because it is already assigned", vq->value, name);
return false;
}
}
}
if (list->value->vqs) {
for (uint16_t i = 0; i < num_queues; i++) {
if (!test_bit(i, vqs)) {
error_setg(errp,
"missing vq %u IOThread assignment in iothread-vq-mapping",
i);
return false;
}
}
}
return true;
}
/**
* apply_iothread_vq_mapping:
* @iothread_vq_mapping_list: The mapping of virtqueues to IOThreads.
* @vq_aio_context: The array of AioContext pointers to fill in.
* @num_queues: The length of @vq_aio_context.
* @errp: If an error occurs, a pointer to the area to store the error.
*
* Fill in the AioContext for each virtqueue in the @vq_aio_context array given
* the iothread-vq-mapping parameter in @iothread_vq_mapping_list.
*
* Returns: %true on success, %false on failure.
**/
static bool apply_iothread_vq_mapping(
IOThreadVirtQueueMappingList *iothread_vq_mapping_list,
AioContext **vq_aio_context,
uint16_t num_queues,
Error **errp)
{
IOThreadVirtQueueMappingList *node;
size_t num_iothreads = 0;
size_t cur_iothread = 0;
if (!validate_iothread_vq_mapping_list(iothread_vq_mapping_list,
num_queues, errp)) {
return false;
}
for (node = iothread_vq_mapping_list; node; node = node->next) {
num_iothreads++;
}
for (node = iothread_vq_mapping_list; node; node = node->next) {
IOThread *iothread = iothread_by_id(node->value->iothread);
AioContext *ctx = iothread_get_aio_context(iothread);
/* Released in virtio_blk_vq_aio_context_cleanup() */
object_ref(OBJECT(iothread));
if (node->value->vqs) {
uint16List *vq;
/* Explicit vq:IOThread assignment */
for (vq = node->value->vqs; vq; vq = vq->next) {
assert(vq->value < num_queues);
vq_aio_context[vq->value] = ctx;
}
} else {
/* Round-robin vq:IOThread assignment */
for (unsigned i = cur_iothread; i < num_queues;
i += num_iothreads) {
vq_aio_context[i] = ctx;
}
}
cur_iothread++;
}
return true;
}
/* Context: BQL held */
static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp)
{
ERRP_GUARD();
VirtIODevice *vdev = VIRTIO_DEVICE(s);
VirtIOBlkConf *conf = &s->conf;
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
if (conf->iothread && conf->iothread_vq_mapping_list) {
error_setg(errp,
"iothread and iothread-vq-mapping properties cannot be set "
"at the same time");
return false;
}
if (conf->iothread || conf->iothread_vq_mapping_list) {
if (!k->set_guest_notifiers || !k->ioeventfd_assign) {
error_setg(errp,
"device is incompatible with iothread "
"(transport does not support notifiers)");
return false;
}
if (!virtio_device_ioeventfd_enabled(vdev)) {
error_setg(errp, "ioeventfd is required for iothread");
return false;
}
/*
* If ioeventfd is (re-)enabled while the guest is running there could
* be block jobs that can conflict.
*/
if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
error_prepend(errp, "cannot start virtio-blk ioeventfd: ");
return false;
}
}
s->vq_aio_context = g_new(AioContext *, conf->num_queues);
if (conf->iothread_vq_mapping_list) {
if (!apply_iothread_vq_mapping(conf->iothread_vq_mapping_list,
s->vq_aio_context,
conf->num_queues,
errp)) {
g_free(s->vq_aio_context);
s->vq_aio_context = NULL;
return false;
}
} else if (conf->iothread) {
AioContext *ctx = iothread_get_aio_context(conf->iothread);
for (unsigned i = 0; i < conf->num_queues; i++) {
s->vq_aio_context[i] = ctx;
}
/* Released in virtio_blk_vq_aio_context_cleanup() */
object_ref(OBJECT(conf->iothread));
} else {
AioContext *ctx = qemu_get_aio_context();
for (unsigned i = 0; i < conf->num_queues; i++) {
s->vq_aio_context[i] = ctx;
}
}
return true;
}
/* Context: BQL held */
static void virtio_blk_vq_aio_context_cleanup(VirtIOBlock *s)
{
VirtIOBlkConf *conf = &s->conf;
assert(!s->ioeventfd_started);
if (conf->iothread_vq_mapping_list) {
IOThreadVirtQueueMappingList *node;
for (node = conf->iothread_vq_mapping_list; node; node = node->next) {
IOThread *iothread = iothread_by_id(node->value->iothread);
object_unref(OBJECT(iothread));
}
}
if (conf->iothread) {
object_unref(OBJECT(conf->iothread));
}
g_free(s->vq_aio_context);
s->vq_aio_context = NULL;
}
/* Context: BQL held */
static int virtio_blk_start_ioeventfd(VirtIODevice *vdev)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
unsigned i;
unsigned nvqs = s->conf.num_queues;
Error *local_err = NULL;
int r;
if (s->ioeventfd_started || s->ioeventfd_starting) {
return 0;
}
s->ioeventfd_starting = true;
/* Set up guest notifier (irq) */
r = k->set_guest_notifiers(qbus->parent, nvqs, true);
if (r != 0) {
error_report("virtio-blk failed to set guest notifier (%d), "
"ensure -accel kvm is set.", r);
goto fail_guest_notifiers;
}
/*
* Batch all the host notifiers in a single transaction to avoid
* quadratic time complexity in address_space_update_ioeventfds().
*/
memory_region_transaction_begin();
/* Set up virtqueue notify */
for (i = 0; i < nvqs; i++) {
r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, true);
if (r != 0) {
int j = i;
fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
while (i--) {
virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
}
/*
* The transaction expects the ioeventfds to be open when it
* commits. Do it now, before the cleanup loop.
*/
memory_region_transaction_commit();
while (j--) {
virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), j);
}
goto fail_host_notifiers;
}
}
memory_region_transaction_commit();
/*
* Try to change the AioContext so that block jobs and other operations can
* co-locate their activity in the same AioContext. If it fails, nevermind.
*/
assert(nvqs > 0); /* enforced during ->realize() */
r = blk_set_aio_context(s->conf.conf.blk, s->vq_aio_context[0],
&local_err);
if (r < 0) {
warn_report_err(local_err);
}
/*
* These fields must be visible to the IOThread when it processes the
* virtqueue, otherwise it will think ioeventfd has not started yet.
*
* Make sure ->ioeventfd_started is false when blk_set_aio_context() is
* called above so that draining does not cause the host notifier to be
* detached/attached prematurely.
*/
s->ioeventfd_starting = false;
s->ioeventfd_started = true;
smp_wmb(); /* paired with aio_notify_accept() on the read side */
/*
* Get this show started by hooking up our callbacks. If drained now,
* virtio_blk_drained_end() will do this later.
* Attaching the notifier also kicks the virtqueues, processing any requests
* they may already have.
*/
if (!blk_in_drain(s->conf.conf.blk)) {
virtio_blk_ioeventfd_attach(s);
}
return 0;
fail_host_notifiers:
k->set_guest_notifiers(qbus->parent, nvqs, false);
fail_guest_notifiers:
s->ioeventfd_disabled = true;
s->ioeventfd_starting = false;
return -ENOSYS;
}
/* Stop notifications for new requests from guest.
*
* Context: BH in IOThread
*/
static void virtio_blk_ioeventfd_stop_vq_bh(void *opaque)
{
VirtQueue *vq = opaque;
EventNotifier *host_notifier = virtio_queue_get_host_notifier(vq);
virtio_queue_aio_detach_host_notifier(vq, qemu_get_current_aio_context());
/*
* Test and clear notifier after disabling event, in case poll callback
* didn't have time to run.
*/
virtio_queue_host_notifier_read(host_notifier);
}
/* Context: BQL held */
static void virtio_blk_stop_ioeventfd(VirtIODevice *vdev)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
BusState *qbus = qdev_get_parent_bus(DEVICE(s));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
unsigned i;
unsigned nvqs = s->conf.num_queues;
if (!s->ioeventfd_started || s->ioeventfd_stopping) {
return;
}
/* Better luck next time. */
if (s->ioeventfd_disabled) {
s->ioeventfd_disabled = false;
s->ioeventfd_started = false;
return;
}
s->ioeventfd_stopping = true;
if (!blk_in_drain(s->conf.conf.blk)) {
for (i = 0; i < nvqs; i++) {
VirtQueue *vq = virtio_get_queue(vdev, i);
AioContext *ctx = s->vq_aio_context[i];
aio_wait_bh_oneshot(ctx, virtio_blk_ioeventfd_stop_vq_bh, vq);
}
}
/*
* Batch all the host notifiers in a single transaction to avoid
* quadratic time complexity in address_space_update_ioeventfds().
*/
memory_region_transaction_begin();
for (i = 0; i < nvqs; i++) {
virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
}
/*
* The transaction expects the ioeventfds to be open when it
* commits. Do it now, before the cleanup loop.
*/
memory_region_transaction_commit();
for (i = 0; i < nvqs; i++) {
virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), i);
}
/*
* Set ->ioeventfd_started to false before draining so that host notifiers
* are not detached/attached anymore.
*/
s->ioeventfd_started = false;
/* Wait for virtio_blk_dma_restart_bh() and in flight I/O to complete */
blk_drain(s->conf.conf.blk);
/*
* Try to switch bs back to the QEMU main loop. If other users keep the
* BlockBackend in the iothread, that's ok
*/
blk_set_aio_context(s->conf.conf.blk, qemu_get_aio_context(), NULL);
/* Clean up guest notifier (irq) */
k->set_guest_notifiers(qbus->parent, nvqs, false);
s->ioeventfd_stopping = false;
}
static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOBlock *s = VIRTIO_BLK(dev);
VirtIOBlkConf *conf = &s->conf;
BlockDriverState *bs;
Error *err = NULL;
unsigned i;
if (!conf->conf.blk) {
error_setg(errp, "drive property not set");
return;
}
if (!blk_is_inserted(conf->conf.blk)) {
error_setg(errp, "Device needs media, but drive is empty");
return;
}
if (conf->num_queues == VIRTIO_BLK_AUTO_NUM_QUEUES) {
conf->num_queues = 1;
}
if (!conf->num_queues) {
error_setg(errp, "num-queues property must be larger than 0");
return;
}
if (conf->queue_size <= 2) {
error_setg(errp, "invalid queue-size property (%" PRIu16 "), "
"must be > 2", conf->queue_size);
return;
}
if (!is_power_of_2(conf->queue_size) ||
conf->queue_size > VIRTQUEUE_MAX_SIZE) {
error_setg(errp, "invalid queue-size property (%" PRIu16 "), "
"must be a power of 2 (max %d)",
conf->queue_size, VIRTQUEUE_MAX_SIZE);
return;
}
if (!blkconf_apply_backend_options(&conf->conf,
!blk_supports_write_perm(conf->conf.blk),
true, errp)) {
return;
}
s->original_wce = blk_enable_write_cache(conf->conf.blk);
if (!blkconf_geometry(&conf->conf, NULL, 65535, 255, 255, errp)) {
return;
}
if (!blkconf_blocksizes(&conf->conf, errp)) {
return;
}
bs = blk_bs(conf->conf.blk);
if (bs->bl.zoned != BLK_Z_NONE) {
virtio_add_feature(&s->host_features, VIRTIO_BLK_F_ZONED);
if (bs->bl.zoned == BLK_Z_HM) {
virtio_clear_feature(&s->host_features, VIRTIO_BLK_F_DISCARD);
}
}
if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD) &&
(!conf->max_discard_sectors ||
conf->max_discard_sectors > BDRV_REQUEST_MAX_SECTORS)) {
error_setg(errp, "invalid max-discard-sectors property (%" PRIu32 ")"
", must be between 1 and %d",
conf->max_discard_sectors, (int)BDRV_REQUEST_MAX_SECTORS);
return;
}
if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_WRITE_ZEROES) &&
(!conf->max_write_zeroes_sectors ||
conf->max_write_zeroes_sectors > BDRV_REQUEST_MAX_SECTORS)) {
error_setg(errp, "invalid max-write-zeroes-sectors property (%" PRIu32
"), must be between 1 and %d",
conf->max_write_zeroes_sectors,
(int)BDRV_REQUEST_MAX_SECTORS);
return;
}
s->config_size = virtio_get_config_size(&virtio_blk_cfg_size_params,
s->host_features);
virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size);
qemu_mutex_init(&s->rq_lock);
s->blk = conf->conf.blk;
s->rq = NULL;
s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1;
for (i = 0; i < conf->num_queues; i++) {
virtio_add_queue(vdev, conf->queue_size, virtio_blk_handle_output);
}
qemu_coroutine_inc_pool_size(conf->num_queues * conf->queue_size / 2);
/* Don't start ioeventfd if transport does not support notifiers. */
if (!virtio_device_ioeventfd_enabled(vdev)) {
s->ioeventfd_disabled = true;
}
virtio_blk_vq_aio_context_init(s, &err);
if (err != NULL) {
error_propagate(errp, err);
for (i = 0; i < conf->num_queues; i++) {
virtio_del_queue(vdev, i);
}
virtio_cleanup(vdev);
return;
}
/*
* This must be after virtio_init() so virtio_blk_dma_restart_cb() gets
* called after ->start_ioeventfd() has already set blk's AioContext.
*/
s->change =
qdev_add_vm_change_state_handler(dev, virtio_blk_dma_restart_cb, s);
blk_ram_registrar_init(&s->blk_ram_registrar, s->blk);
blk_set_dev_ops(s->blk, &virtio_block_ops, s);
blk_iostatus_enable(s->blk);
add_boot_device_lchs(dev, "/disk@0,0",
conf->conf.lcyls,
conf->conf.lheads,
conf->conf.lsecs);
}
static void virtio_blk_device_unrealize(DeviceState *dev)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOBlock *s = VIRTIO_BLK(dev);
VirtIOBlkConf *conf = &s->conf;
unsigned i;
blk_drain(s->blk);
del_boot_device_lchs(dev, "/disk@0,0");
virtio_blk_vq_aio_context_cleanup(s);
for (i = 0; i < conf->num_queues; i++) {
virtio_del_queue(vdev, i);
}
qemu_coroutine_dec_pool_size(conf->num_queues * conf->queue_size / 2);
qemu_mutex_destroy(&s->rq_lock);
blk_ram_registrar_destroy(&s->blk_ram_registrar);
qemu_del_vm_change_state_handler(s->change);
blockdev_mark_auto_del(s->blk);
virtio_cleanup(vdev);
}
static void virtio_blk_instance_init(Object *obj)
{
VirtIOBlock *s = VIRTIO_BLK(obj);
device_add_bootindex_property(obj, &s->conf.conf.bootindex,
"bootindex", "/disk@0,0",
DEVICE(obj));
}
static const VMStateDescription vmstate_virtio_blk = {
.name = "virtio-blk",
.minimum_version_id = 2,
.version_id = 2,
.fields = (const VMStateField[]) {
VMSTATE_VIRTIO_DEVICE,
VMSTATE_END_OF_LIST()
},
};
static Property virtio_blk_properties[] = {
DEFINE_BLOCK_PROPERTIES(VirtIOBlock, conf.conf),
DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf),
DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf),
DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial),
DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features,
VIRTIO_BLK_F_CONFIG_WCE, true),
DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0,
true),
DEFINE_PROP_UINT16("num-queues", VirtIOBlock, conf.num_queues,
VIRTIO_BLK_AUTO_NUM_QUEUES),
DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 256),
DEFINE_PROP_BOOL("seg-max-adjust", VirtIOBlock, conf.seg_max_adjust, true),
DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD,
IOThread *),
DEFINE_PROP_IOTHREAD_VQ_MAPPING_LIST("iothread-vq-mapping", VirtIOBlock,
conf.iothread_vq_mapping_list),
DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features,
VIRTIO_BLK_F_DISCARD, true),
DEFINE_PROP_BOOL("report-discard-granularity", VirtIOBlock,
conf.report_discard_granularity, true),
DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features,
VIRTIO_BLK_F_WRITE_ZEROES, true),
DEFINE_PROP_UINT32("max-discard-sectors", VirtIOBlock,
conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS),
DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock,
conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS),
DEFINE_PROP_BOOL("x-enable-wce-if-config-wce", VirtIOBlock,
conf.x_enable_wce_if_config_wce, true),
DEFINE_PROP_END_OF_LIST(),
};
static void virtio_blk_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
device_class_set_props(dc, virtio_blk_properties);
dc->vmsd = &vmstate_virtio_blk;
set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
vdc->realize = virtio_blk_device_realize;
vdc->unrealize = virtio_blk_device_unrealize;
vdc->get_config = virtio_blk_update_config;
vdc->set_config = virtio_blk_set_config;
vdc->get_features = virtio_blk_get_features;
vdc->set_status = virtio_blk_set_status;
vdc->reset = virtio_blk_reset;
vdc->save = virtio_blk_save_device;
vdc->load = virtio_blk_load_device;
vdc->start_ioeventfd = virtio_blk_start_ioeventfd;
vdc->stop_ioeventfd = virtio_blk_stop_ioeventfd;
}
static const TypeInfo virtio_blk_info = {
.name = TYPE_VIRTIO_BLK,
.parent = TYPE_VIRTIO_DEVICE,
.instance_size = sizeof(VirtIOBlock),
.instance_init = virtio_blk_instance_init,
.class_init = virtio_blk_class_init,
};
static void virtio_register_types(void)
{
type_register_static(&virtio_blk_info);
}
type_init(virtio_register_types)
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