diff options
Diffstat (limited to 'drivers/nvme/target/passthru.c')
| -rw-r--r-- | drivers/nvme/target/passthru.c | 544 |
1 files changed, 544 insertions, 0 deletions
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c new file mode 100644 index 000000000000..89d91dc999a6 --- /dev/null +++ b/drivers/nvme/target/passthru.c @@ -0,0 +1,544 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * NVMe Over Fabrics Target Passthrough command implementation. + * + * Copyright (c) 2017-2018 Western Digital Corporation or its + * affiliates. + * Copyright (c) 2019-2020, Eideticom Inc. + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> + +#include "../host/nvme.h" +#include "nvmet.h" + +MODULE_IMPORT_NS(NVME_TARGET_PASSTHRU); + +/* + * xarray to maintain one passthru subsystem per nvme controller. + */ +static DEFINE_XARRAY(passthru_subsystems); + +static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req) +{ + struct nvmet_ctrl *ctrl = req->sq->ctrl; + struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl; + u16 status = NVME_SC_SUCCESS; + struct nvme_id_ctrl *id; + u32 max_hw_sectors; + int page_shift; + + id = kzalloc(sizeof(*id), GFP_KERNEL); + if (!id) + return NVME_SC_INTERNAL; + + status = nvmet_copy_from_sgl(req, 0, id, sizeof(*id)); + if (status) + goto out_free; + + id->cntlid = cpu_to_le16(ctrl->cntlid); + id->ver = cpu_to_le32(ctrl->subsys->ver); + + /* + * The passthru NVMe driver may have a limit on the number of segments + * which depends on the host's memory fragementation. To solve this, + * ensure mdts is limited to the pages equal to the number of segments. + */ + max_hw_sectors = min_not_zero(pctrl->max_segments << (PAGE_SHIFT - 9), + pctrl->max_hw_sectors); + + page_shift = NVME_CAP_MPSMIN(ctrl->cap) + 12; + + id->mdts = ilog2(max_hw_sectors) + 9 - page_shift; + + id->acl = 3; + /* + * We export aerl limit for the fabrics controller, update this when + * passthru based aerl support is added. + */ + id->aerl = NVMET_ASYNC_EVENTS - 1; + + /* emulate kas as most of the PCIe ctrl don't have a support for kas */ + id->kas = cpu_to_le16(NVMET_KAS); + + /* don't support host memory buffer */ + id->hmpre = 0; + id->hmmin = 0; + + id->sqes = min_t(__u8, ((0x6 << 4) | 0x6), id->sqes); + id->cqes = min_t(__u8, ((0x4 << 4) | 0x4), id->cqes); + id->maxcmd = cpu_to_le16(NVMET_MAX_CMD); + + /* don't support fuse commands */ + id->fuses = 0; + + id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */ + if (ctrl->ops->flags & NVMF_KEYED_SGLS) + id->sgls |= cpu_to_le32(1 << 2); + if (req->port->inline_data_size) + id->sgls |= cpu_to_le32(1 << 20); + + /* + * When passsthru controller is setup using nvme-loop transport it will + * export the passthru ctrl subsysnqn (PCIe NVMe ctrl) and will fail in + * the nvme/host/core.c in the nvme_init_subsystem()->nvme_active_ctrl() + * code path with duplicate ctr subsynqn. In order to prevent that we + * mask the passthru-ctrl subsysnqn with the target ctrl subsysnqn. + */ + memcpy(id->subnqn, ctrl->subsysnqn, sizeof(id->subnqn)); + + /* use fabric id-ctrl values */ + id->ioccsz = cpu_to_le32((sizeof(struct nvme_command) + + req->port->inline_data_size) / 16); + id->iorcsz = cpu_to_le32(sizeof(struct nvme_completion) / 16); + + id->msdbd = ctrl->ops->msdbd; + + /* Support multipath connections with fabrics */ + id->cmic |= 1 << 1; + + /* Disable reservations, see nvmet_parse_passthru_io_cmd() */ + id->oncs &= cpu_to_le16(~NVME_CTRL_ONCS_RESERVATIONS); + + status = nvmet_copy_to_sgl(req, 0, id, sizeof(struct nvme_id_ctrl)); + +out_free: + kfree(id); + return status; +} + +static u16 nvmet_passthru_override_id_ns(struct nvmet_req *req) +{ + u16 status = NVME_SC_SUCCESS; + struct nvme_id_ns *id; + int i; + + id = kzalloc(sizeof(*id), GFP_KERNEL); + if (!id) + return NVME_SC_INTERNAL; + + status = nvmet_copy_from_sgl(req, 0, id, sizeof(struct nvme_id_ns)); + if (status) + goto out_free; + + for (i = 0; i < (id->nlbaf + 1); i++) + if (id->lbaf[i].ms) + memset(&id->lbaf[i], 0, sizeof(id->lbaf[i])); + + id->flbas = id->flbas & ~(1 << 4); + + /* + * Presently the NVMEof target code does not support sending + * metadata, so we must disable it here. This should be updated + * once target starts supporting metadata. + */ + id->mc = 0; + + status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id)); + +out_free: + kfree(id); + return status; +} + +static void nvmet_passthru_execute_cmd_work(struct work_struct *w) +{ + struct nvmet_req *req = container_of(w, struct nvmet_req, p.work); + struct request *rq = req->p.rq; + u16 status; + + nvme_execute_passthru_rq(rq); + + status = nvme_req(rq)->status; + if (status == NVME_SC_SUCCESS && + req->cmd->common.opcode == nvme_admin_identify) { + switch (req->cmd->identify.cns) { + case NVME_ID_CNS_CTRL: + nvmet_passthru_override_id_ctrl(req); + break; + case NVME_ID_CNS_NS: + nvmet_passthru_override_id_ns(req); + break; + } + } + + req->cqe->result = nvme_req(rq)->result; + nvmet_req_complete(req, status); + blk_put_request(rq); +} + +static void nvmet_passthru_req_done(struct request *rq, + blk_status_t blk_status) +{ + struct nvmet_req *req = rq->end_io_data; + + req->cqe->result = nvme_req(rq)->result; + nvmet_req_complete(req, nvme_req(rq)->status); + blk_put_request(rq); +} + +static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq) +{ + int sg_cnt = req->sg_cnt; + struct scatterlist *sg; + int op_flags = 0; + struct bio *bio; + int i, ret; + + if (req->cmd->common.opcode == nvme_cmd_flush) + op_flags = REQ_FUA; + else if (nvme_is_write(req->cmd)) + op_flags = REQ_SYNC | REQ_IDLE; + + bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES)); + bio->bi_end_io = bio_put; + bio->bi_opf = req_op(rq) | op_flags; + + for_each_sg(req->sg, sg, req->sg_cnt, i) { + if (bio_add_pc_page(rq->q, bio, sg_page(sg), sg->length, + sg->offset) < sg->length) { + bio_put(bio); + return -EINVAL; + } + sg_cnt--; + } + + ret = blk_rq_append_bio(rq, &bio); + if (unlikely(ret)) { + bio_put(bio); + return ret; + } + + return 0; +} + +static void nvmet_passthru_execute_cmd(struct nvmet_req *req) +{ + struct nvme_ctrl *ctrl = nvmet_req_passthru_ctrl(req); + struct request_queue *q = ctrl->admin_q; + struct nvme_ns *ns = NULL; + struct request *rq = NULL; + u32 effects; + u16 status; + int ret; + + if (likely(req->sq->qid != 0)) { + u32 nsid = le32_to_cpu(req->cmd->common.nsid); + + ns = nvme_find_get_ns(ctrl, nsid); + if (unlikely(!ns)) { + pr_err("failed to get passthru ns nsid:%u\n", nsid); + status = NVME_SC_INVALID_NS | NVME_SC_DNR; + goto fail_out; + } + + q = ns->queue; + } + + rq = nvme_alloc_request(q, req->cmd, BLK_MQ_REQ_NOWAIT, NVME_QID_ANY); + if (IS_ERR(rq)) { + rq = NULL; + status = NVME_SC_INTERNAL; + goto fail_out; + } + + if (req->sg_cnt) { + ret = nvmet_passthru_map_sg(req, rq); + if (unlikely(ret)) { + status = NVME_SC_INTERNAL; + goto fail_out; + } + } + + /* + * If there are effects for the command we are about to execute, or + * an end_req function we need to use nvme_execute_passthru_rq() + * synchronously in a work item seeing the end_req function and + * nvme_passthru_end() can't be called in the request done callback + * which is typically in interrupt context. + */ + effects = nvme_command_effects(ctrl, ns, req->cmd->common.opcode); + if (req->p.use_workqueue || effects) { + INIT_WORK(&req->p.work, nvmet_passthru_execute_cmd_work); + req->p.rq = rq; + schedule_work(&req->p.work); + } else { + rq->end_io_data = req; + blk_execute_rq_nowait(rq->q, ns ? ns->disk : NULL, rq, 0, + nvmet_passthru_req_done); + } + + if (ns) + nvme_put_ns(ns); + + return; + +fail_out: + if (ns) + nvme_put_ns(ns); + nvmet_req_complete(req, status); + blk_put_request(rq); +} + +/* + * We need to emulate set host behaviour to ensure that any requested + * behaviour of the target's host matches the requested behaviour + * of the device's host and fail otherwise. + */ +static void nvmet_passthru_set_host_behaviour(struct nvmet_req *req) +{ + struct nvme_ctrl *ctrl = nvmet_req_passthru_ctrl(req); + struct nvme_feat_host_behavior *host; + u16 status = NVME_SC_INTERNAL; + int ret; + + host = kzalloc(sizeof(*host) * 2, GFP_KERNEL); + if (!host) + goto out_complete_req; + + ret = nvme_get_features(ctrl, NVME_FEAT_HOST_BEHAVIOR, 0, + host, sizeof(*host), NULL); + if (ret) + goto out_free_host; + + status = nvmet_copy_from_sgl(req, 0, &host[1], sizeof(*host)); + if (status) + goto out_free_host; + + if (memcmp(&host[0], &host[1], sizeof(host[0]))) { + pr_warn("target host has requested different behaviour from the local host\n"); + status = NVME_SC_INTERNAL; + } + +out_free_host: + kfree(host); +out_complete_req: + nvmet_req_complete(req, status); +} + +static u16 nvmet_setup_passthru_command(struct nvmet_req *req) +{ + req->p.use_workqueue = false; + req->execute = nvmet_passthru_execute_cmd; + return NVME_SC_SUCCESS; +} + +u16 nvmet_parse_passthru_io_cmd(struct nvmet_req *req) +{ + switch (req->cmd->common.opcode) { + case nvme_cmd_resv_register: + case nvme_cmd_resv_report: + case nvme_cmd_resv_acquire: + case nvme_cmd_resv_release: + /* + * Reservations cannot be supported properly because the + * underlying device has no way of differentiating different + * hosts that connect via fabrics. This could potentially be + * emulated in the future if regular targets grow support for + * this feature. + */ + return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; + } + + return nvmet_setup_passthru_command(req); +} + +/* + * Only features that are emulated or specifically allowed in the list are + * passed down to the controller. This function implements the allow list for + * both get and set features. + */ +static u16 nvmet_passthru_get_set_features(struct nvmet_req *req) +{ + switch (le32_to_cpu(req->cmd->features.fid)) { + case NVME_FEAT_ARBITRATION: + case NVME_FEAT_POWER_MGMT: + case NVME_FEAT_LBA_RANGE: + case NVME_FEAT_TEMP_THRESH: + case NVME_FEAT_ERR_RECOVERY: + case NVME_FEAT_VOLATILE_WC: + case NVME_FEAT_WRITE_ATOMIC: + case NVME_FEAT_AUTO_PST: + case NVME_FEAT_TIMESTAMP: + case NVME_FEAT_HCTM: + case NVME_FEAT_NOPSC: + case NVME_FEAT_RRL: + case NVME_FEAT_PLM_CONFIG: + case NVME_FEAT_PLM_WINDOW: + case NVME_FEAT_HOST_BEHAVIOR: + case NVME_FEAT_SANITIZE: + case NVME_FEAT_VENDOR_START ... NVME_FEAT_VENDOR_END: + return nvmet_setup_passthru_command(req); + + case NVME_FEAT_ASYNC_EVENT: + /* There is no support for forwarding ASYNC events */ + case NVME_FEAT_IRQ_COALESCE: + case NVME_FEAT_IRQ_CONFIG: + /* The IRQ settings will not apply to the target controller */ + case NVME_FEAT_HOST_MEM_BUF: + /* + * Any HMB that's set will not be passed through and will + * not work as expected + */ + case NVME_FEAT_SW_PROGRESS: + /* + * The Pre-Boot Software Load Count doesn't make much + * sense for a target to export + */ + case NVME_FEAT_RESV_MASK: + case NVME_FEAT_RESV_PERSIST: + /* No reservations, see nvmet_parse_passthru_io_cmd() */ + default: + return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; + } +} + +u16 nvmet_parse_passthru_admin_cmd(struct nvmet_req *req) +{ + /* + * Passthru all vendor specific commands + */ + if (req->cmd->common.opcode >= nvme_admin_vendor_start) + return nvmet_setup_passthru_command(req); + + switch (req->cmd->common.opcode) { + case nvme_admin_async_event: + req->execute = nvmet_execute_async_event; + return NVME_SC_SUCCESS; + case nvme_admin_keep_alive: + /* + * Most PCIe ctrls don't support keep alive cmd, we route keep + * alive to the non-passthru mode. In future please change this + * code when PCIe ctrls with keep alive support available. + */ + req->execute = nvmet_execute_keep_alive; + return NVME_SC_SUCCESS; + case nvme_admin_set_features: + switch (le32_to_cpu(req->cmd->features.fid)) { + case NVME_FEAT_ASYNC_EVENT: + case NVME_FEAT_KATO: + case NVME_FEAT_NUM_QUEUES: + case NVME_FEAT_HOST_ID: + req->execute = nvmet_execute_set_features; + return NVME_SC_SUCCESS; + case NVME_FEAT_HOST_BEHAVIOR: + req->execute = nvmet_passthru_set_host_behaviour; + return NVME_SC_SUCCESS; + default: + return nvmet_passthru_get_set_features(req); + } + break; + case nvme_admin_get_features: + switch (le32_to_cpu(req->cmd->features.fid)) { + case NVME_FEAT_ASYNC_EVENT: + case NVME_FEAT_KATO: + case NVME_FEAT_NUM_QUEUES: + case NVME_FEAT_HOST_ID: + req->execute = nvmet_execute_get_features; + return NVME_SC_SUCCESS; + default: + return nvmet_passthru_get_set_features(req); + } + break; + case nvme_admin_identify: + switch (req->cmd->identify.cns) { + case NVME_ID_CNS_CTRL: + req->execute = nvmet_passthru_execute_cmd; + req->p.use_workqueue = true; + return NVME_SC_SUCCESS; + case NVME_ID_CNS_NS: + req->execute = nvmet_passthru_execute_cmd; + req->p.use_workqueue = true; + return NVME_SC_SUCCESS; + default: + return nvmet_setup_passthru_command(req); + } + case nvme_admin_get_log_page: + return nvmet_setup_passthru_command(req); + default: + /* Reject commands not in the allowlist above */ + return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; + } +} + +int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys) +{ + struct nvme_ctrl *ctrl; + int ret = -EINVAL; + void *old; + + mutex_lock(&subsys->lock); + if (!subsys->passthru_ctrl_path) + goto out_unlock; + if (subsys->passthru_ctrl) + goto out_unlock; + + if (subsys->nr_namespaces) { + pr_info("cannot enable both passthru and regular namespaces for a single subsystem"); + goto out_unlock; + } + + ctrl = nvme_ctrl_get_by_path(subsys->passthru_ctrl_path); + if (IS_ERR(ctrl)) { + ret = PTR_ERR(ctrl); + pr_err("failed to open nvme controller %s\n", + subsys->passthru_ctrl_path); + + goto out_unlock; + } + + old = xa_cmpxchg(&passthru_subsystems, ctrl->cntlid, NULL, + subsys, GFP_KERNEL); + if (xa_is_err(old)) { + ret = xa_err(old); + goto out_put_ctrl; + } + + if (old) + goto out_put_ctrl; + + subsys->passthru_ctrl = ctrl; + subsys->ver = ctrl->vs; + + if (subsys->ver < NVME_VS(1, 2, 1)) { + pr_warn("nvme controller version is too old: %llu.%llu.%llu, advertising 1.2.1\n", + NVME_MAJOR(subsys->ver), NVME_MINOR(subsys->ver), + NVME_TERTIARY(subsys->ver)); + subsys->ver = NVME_VS(1, 2, 1); + } + + mutex_unlock(&subsys->lock); + return 0; + +out_put_ctrl: + nvme_put_ctrl(ctrl); +out_unlock: + mutex_unlock(&subsys->lock); + return ret; +} + +static void __nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys) +{ + if (subsys->passthru_ctrl) { + xa_erase(&passthru_subsystems, subsys->passthru_ctrl->cntlid); + nvme_put_ctrl(subsys->passthru_ctrl); + } + subsys->passthru_ctrl = NULL; + subsys->ver = NVMET_DEFAULT_VS; +} + +void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys) +{ + mutex_lock(&subsys->lock); + __nvmet_passthru_ctrl_disable(subsys); + mutex_unlock(&subsys->lock); +} + +void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys) +{ + mutex_lock(&subsys->lock); + __nvmet_passthru_ctrl_disable(subsys); + mutex_unlock(&subsys->lock); + kfree(subsys->passthru_ctrl_path); +} |