diff options
Diffstat (limited to 'hw/block/virtio-blk.c')
| -rw-r--r-- | hw/block/virtio-blk.c | 249 |
1 files changed, 232 insertions, 17 deletions
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index cf7f47eaba..0cc3c590b9 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -28,9 +28,28 @@ #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" -/* We don't support discard yet, hide associated config fields. */ +/* Config size before the discard support (hide associated config fields) */ #define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \ max_discard_sectors) +/* + * Starting from the discard feature, we can use this array to properly + * set the config size depending on the features enabled. + */ +static VirtIOFeature feature_sizes[] = { + {.flags = 1ULL << VIRTIO_BLK_F_DISCARD, + .end = virtio_endof(struct virtio_blk_config, discard_sector_alignment)}, + {.flags = 1ULL << VIRTIO_BLK_F_WRITE_ZEROES, + .end = virtio_endof(struct virtio_blk_config, write_zeroes_may_unmap)}, + {} +}; + +static void virtio_blk_set_config_size(VirtIOBlock *s, uint64_t host_features) +{ + s->config_size = MAX(VIRTIO_BLK_CFG_SIZE, + virtio_feature_get_config_size(feature_sizes, host_features)); + + assert(s->config_size <= sizeof(struct virtio_blk_config)); +} static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq, VirtIOBlockReq *req) @@ -65,7 +84,7 @@ static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status) } static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error, - bool is_read) + bool is_read, bool acct_failed) { VirtIOBlock *s = req->dev; BlockErrorAction action = blk_get_error_action(s->blk, is_read, error); @@ -78,7 +97,9 @@ static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error, s->rq = req; } else if (action == BLOCK_ERROR_ACTION_REPORT) { virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); - block_acct_failed(blk_get_stats(s->blk), &req->acct); + if (acct_failed) { + block_acct_failed(blk_get_stats(s->blk), &req->acct); + } virtio_blk_free_request(req); } @@ -116,7 +137,7 @@ static void virtio_blk_rw_complete(void *opaque, int ret) * 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)) { + if (virtio_blk_handle_rw_error(req, -ret, is_read, true)) { continue; } } @@ -135,7 +156,7 @@ static void virtio_blk_flush_complete(void *opaque, int ret) aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); if (ret) { - if (virtio_blk_handle_rw_error(req, -ret, 0)) { + if (virtio_blk_handle_rw_error(req, -ret, 0, true)) { goto out; } } @@ -148,6 +169,30 @@ out: aio_context_release(blk_get_aio_context(s->conf.conf.blk)); } +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; + + aio_context_acquire(blk_get_aio_context(s->conf.conf.blk)); + if (ret) { + if (virtio_blk_handle_rw_error(req, -ret, false, is_write_zeroes)) { + goto out; + } + } + + 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); + +out: + aio_context_release(blk_get_aio_context(s->conf.conf.blk)); +} + #ifdef __linux__ typedef struct { @@ -243,7 +288,7 @@ static int virtio_blk_handle_scsi_req(VirtIOBlockReq *req) */ scsi = (void *)elem->in_sg[elem->in_num - 2].iov_base; - if (!blk->conf.scsi) { + if (!virtio_has_feature(blk->host_features, VIRTIO_BLK_F_SCSI)) { status = VIRTIO_BLK_S_UNSUPP; goto fail; } @@ -481,6 +526,84 @@ static bool virtio_blk_sect_range_ok(VirtIOBlock *dev, 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; +} + static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb) { uint32_t type; @@ -582,6 +705,47 @@ static int virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb) virtio_blk_free_request(req); 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))) { + 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); @@ -675,6 +839,7 @@ static void virtio_blk_dma_restart_bh(void *opaque) if (mrb.num_reqs) { virtio_blk_submit_multireq(s->blk, &mrb); } + blk_dec_in_flight(s->conf.conf.blk); aio_context_release(blk_get_aio_context(s->conf.conf.blk)); } @@ -688,8 +853,11 @@ static void virtio_blk_dma_restart_cb(void *opaque, int running, } if (!s->bh) { + /* FIXME The data plane is not started yet, so these requests are + * processed in the main thread. */ s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk), virtio_blk_dma_restart_bh, s); + blk_inc_in_flight(s->conf.conf.blk); qemu_bh_schedule(s->bh); } } @@ -761,8 +929,25 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) blkcfg.alignment_offset = 0; blkcfg.wce = blk_enable_write_cache(s->blk); virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues); - memcpy(config, &blkcfg, VIRTIO_BLK_CFG_SIZE); - QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg)); + if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_DISCARD)) { + virtio_stl_p(vdev, &blkcfg.max_discard_sectors, + s->conf.max_discard_sectors); + virtio_stl_p(vdev, &blkcfg.discard_sector_alignment, + blk_size >> 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); + } + memcpy(config, &blkcfg, s->config_size); } static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) @@ -770,8 +955,7 @@ 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, VIRTIO_BLK_CFG_SIZE); - QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg)); + memcpy(&blkcfg, config, s->config_size); aio_context_acquire(blk_get_aio_context(s->blk)); blk_set_enable_write_cache(s->blk, blkcfg.wce != 0); @@ -783,12 +967,15 @@ static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, { 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)) { - if (s->conf.scsi) { + if (virtio_has_feature(s->host_features, VIRTIO_BLK_F_SCSI)) { error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0"); return 0; } @@ -797,9 +984,6 @@ static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); } - if (s->conf.config_wce) { - virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE); - } if (blk_enable_write_cache(s->blk)) { virtio_add_feature(&features, VIRTIO_BLK_F_WCE); } @@ -954,7 +1138,28 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) return; } - virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, VIRTIO_BLK_CFG_SIZE); + 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; + } + + virtio_blk_set_config_size(s, s->host_features); + + virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, s->config_size); s->blk = conf->conf.blk; s->rq = NULL; @@ -1013,9 +1218,11 @@ static Property virtio_blk_properties[] = { DEFINE_BLOCK_ERROR_PROPERTIES(VirtIOBlock, conf.conf), DEFINE_BLOCK_CHS_PROPERTIES(VirtIOBlock, conf.conf), DEFINE_PROP_STRING("serial", VirtIOBlock, conf.serial), - DEFINE_PROP_BIT("config-wce", VirtIOBlock, conf.config_wce, 0, true), + DEFINE_PROP_BIT64("config-wce", VirtIOBlock, host_features, + VIRTIO_BLK_F_CONFIG_WCE, true), #ifdef __linux__ - DEFINE_PROP_BIT("scsi", VirtIOBlock, conf.scsi, 0, false), + DEFINE_PROP_BIT64("scsi", VirtIOBlock, host_features, + VIRTIO_BLK_F_SCSI, false), #endif DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0, true), @@ -1023,6 +1230,14 @@ static Property virtio_blk_properties[] = { DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128), DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD, IOThread *), + DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features, + VIRTIO_BLK_F_DISCARD, 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_END_OF_LIST(), }; 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