From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f99.google.com (mail-oa1-f99.google.com [209.85.160.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 391DE4825D5 for ; Wed, 9 Sep 2026 22:29:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.99 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788992958; cv=none; b=CU3R72utkwgn6sjjzKjgQTjTdQfPBzaOcspgSN0GB42aD7ETkYXZLIijd0PWTi6Ni3zDQ59HLIsGwsgRtN3LqwJ3RzjMqlOE+5iwwPuw28RkGyiucJFI2jxIODjDijxKVbnTXIRr7egf/9s+W6lYKOJk+p92GxgSCyRL5PhjIOA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788992958; c=relaxed/simple; bh=ZsRCPU0J121h1w/y85vunBI0gv6iQjmpHXlh3qUdYlg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QdmF8kf3VmTEKxr0xcAubu95K/p/KXfypoe+D5nlNT18s52fLKp0KvokwFFmXNRVfdryMeDl38f6LZJQnakzpLZZvQs/QbpUvE6+eczoX2F2vP/13drcR+fTgGjuJN0XakUciXTsEr9L5q3C8c10J+vxNnFRnVj/kURCIeKAQ9k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com; spf=pass smtp.mailfrom=purestorage.com; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b=LMnDcxSW; arc=none smtp.client-ip=209.85.160.99 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=purestorage.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b="LMnDcxSW" Received: by mail-oa1-f99.google.com with SMTP id 586e51a60fabf-46b08568bc4so157621fac.3 for ; Wed, 09 Sep 2026 15:29:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; t=1788992944; x=1789597744; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=ImWYQroYLYn1yUntaG3yDyG9poZ7C84uz/cQieFkqu0=; b=LMnDcxSWOPQs3Iluim5mr8nhBkssXls8io+aEc8xhd83PNawOi0+HS6tnL3fvPYHaF Z0iCc+OYZyTwjDW/F7qqK6yJag2bT21rnE2ASpUB/iZ8TmQjXU/O46v3sSrqcT04NA1E dtwypgDV+a3DHU9lUzP0dckuysAdmbq7A/WKjXl5/lKNWkcZBNVY4gyAjX6sEGR6jkpk jCrxkSHb80WRk0Bti8ABy1rfmvmoOn3W9Uw0g44odA4sEEH6c8PkWTw6ii23hZSiGNJc 7pi6YE71ax6Tib3PdUBqj7Cmr7GDnTAkUbGvx7YnJjbSUa9v40Tb0IwmJD7QzcVmYCUY gwDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788992944; x=1789597744; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=ImWYQroYLYn1yUntaG3yDyG9poZ7C84uz/cQieFkqu0=; b=cDxkkDa8Lnu4qybOc8BsaCRANpPmrF7v5KtQynTjK03DFJe7MLLwN9tw8hAdpVUMIu sl/fT+4NDBVBg4sDl52IYPNJHL9nu+qJ3malcgXUZHEA/Az2noxA67dFmnXKkaaD/Ter Zu7y3Iew72Yxr8UAiLQU0FxV0dzZ+vVd9Le7FAZsBK1x2WWhRzfKpJ6ozGnk/qX+9RGf oX6pMaVnf9WFGsyrFZKznc1W6oZ0DvbGTEwr4kd/FR0RDwZ2hsvaxqpiW9je/jQa4auS +iOXqecdPaDx3lnMuAQwDtSethxr1cgRj+advSR9+SmNqzmOiknATK5DZbC3mGFTKlb3 s5kg== X-Gm-Message-State: AFuF++ltEnnDUN4B/mGgTb4dThhiQaSneiBiUWGOkLm7x1S4oURkKmM6 /mNhTctqIGJgbLFF/G8QyA038Sb/FiyVD+LC8oVxWdDKVOOmjHtRFXQ2K93aP4ndd7Jy/prueoV dlW6ntVdoifvY1NgAcnG53lhAVwJmMw1r5KCH X-Gm-Gg: AYBFou1tKymW5WpoVEfdOHsWDUZIhMkAXSdFm98WpUdT7Vo0JltpW9nm21LMRZLJnDE A1ThevFu0E4HqM5TaZ+BVlCCLjSIGZkS2oWb3VPonoC9newxfOUYHtreTGJMkA3X3LPUvdj1gbq WCWo8Ke+c4yx8cr3A8jlAP7OTAj0VM/56Khb61zf03q5CC0QCn4vLT13gsKxvy9FCWbcUZH4xRR Hv0VlvWnL03ika3RsGtQDgiWbg/IT6fAk2enWYkUT1/2mrilXTsG/UfggXQb+wf9Kjn4DwIP+jY Tfab2UIh+TZOlGwZmeOnoup3vL0XvCQXP6zg/md0NN2EWTRZCCG0Gb3MdzG74qY5kej7g/lxvGm 3I9NQWECnuIFk8DwbH5IXg9gzk4r/u8JW X-Received: by 2002:a05:6830:f89:b0:7ee:363d:ce16 with SMTP id 46e09a7af769-7fb76e3cd73mr16877278a34.0.1788992944121; Wed, 09 Sep 2026 15:29:04 -0700 (PDT) Received: from c7-smtp-2026.dev.purestorage.com ([208.88.159.129]) by smtp-relay.gmail.com with ESMTPS id 46e09a7af769-7f9f6aa689fsm2773280a34.5.2026.09.09.15.29.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Sep 2026 15:29:04 -0700 (PDT) X-Relaying-Domain: purestorage.com Received: from dev-csander.dev.purestorage.com (dev-csander.dev.purestorage.com [10.112.12.104]) by c7-smtp-2026.dev.purestorage.com (Postfix) with ESMTP id AFA1C402BE; Wed, 9 Sep 2026 16:29:03 -0600 (MDT) Received: by dev-csander.dev.purestorage.com (Postfix, from userid 1557716354) id AD682E40322; Wed, 9 Sep 2026 16:29:03 -0600 (MDT) From: Caleb Sander Mateos To: Jens Axboe , Keith Busch , Christoph Hellwig , Sagi Grimberg Cc: io-uring@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Caleb Sander Mateos Subject: [PATCH 6/6] nvme/ioctl: support fixed buffer for metadata Date: Wed, 9 Sep 2026 16:28:36 -0600 Message-ID: <20260909222836.2475352-7-csander@purestorage.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260909222836.2475352-1-csander@purestorage.com> References: <20260909222836.2475352-1-csander@purestorage.com> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit io_uring NVMe passthrough supports using a "fixed" (registered) buffer for data, but not metadata. On high-IOPS workloads, the pinning and unpinning overhead for the metadata pages is significant and could be avoided if fixed metadata buffers were supported. Define a NVME_URING_CMD_FIXED_METADATA bit for the nvme_uring_cmd's flags field (which is currently required to be 0) to indicate that the metadata buffer belongs to a fixed buffer registered with the io_uring. The metadata fixed buffer index is specified in a metadata_buf_index field replacing the existing rsvd1 in nvme_uring_cmd. If NVME_URING_CMD_FIXED_METADATA is set, the metadata iov_iter is obtained from io_uring_cmd_import_fixed_metadata() instead of iov_iter_ubuf(). Signed-off-by: Caleb Sander Mateos --- drivers/nvme/host/ioctl.c | 21 ++++++++++++++++----- include/uapi/linux/nvme_ioctl.h | 5 ++++- 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c index 8e722184ecf1..4da8cf92c2e0 100644 --- a/drivers/nvme/host/ioctl.c +++ b/drivers/nvme/host/ioctl.c @@ -488,21 +488,22 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns, struct iov_iter iter, meta_iter; struct iov_iter *map_iter = NULL, *map_meta_iter = NULL; struct request *req; blk_opf_t rq_flags = 0; blk_mq_req_flags_t blk_flags = 0; + u8 flags = READ_ONCE(cmd->flags); u32 metadata_len, data_len; u64 metadata, addr; u32 timeout_ms; int ddir; int ret; - c.common.opcode = READ_ONCE(cmd->opcode); - c.common.flags = READ_ONCE(cmd->flags); - if (c.common.flags) + if (flags & ~NVME_URING_CMD_FIXED_METADATA) return -EINVAL; + c.common.opcode = READ_ONCE(cmd->opcode); + c.common.flags = 0; c.common.command_id = 0; c.common.nsid = cpu_to_le32(cmd->nsid); if (!nvme_validate_passthru_nsid(ctrl, ns, le32_to_cpu(c.common.nsid))) return -EINVAL; @@ -539,12 +540,22 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns, return ret; map_iter = &iter; } if (data_len && metadata && metadata_len) { - iov_iter_ubuf(&meta_iter, ddir, nvme_to_user_ptr(metadata), - metadata_len); + if (flags & NVME_URING_CMD_FIXED_METADATA) { + u16 buf_index = READ_ONCE(cmd->metadata_buf_index); + + ret = io_uring_cmd_import_fixed_metadata( + ioucmd, buf_index, metadata, metadata_len, ddir, + &meta_iter, issue_flags); + if (ret < 0) + return ret; + } else { + iov_iter_ubuf(&meta_iter, ddir, nvme_to_user_ptr(metadata), + metadata_len); + } map_meta_iter = &meta_iter; } if (issue_flags & IO_URING_F_NONBLOCK) { rq_flags |= REQ_NOWAIT; diff --git a/include/uapi/linux/nvme_ioctl.h b/include/uapi/linux/nvme_ioctl.h index 2f76cba67166..93973f636b48 100644 --- a/include/uapi/linux/nvme_ioctl.h +++ b/include/uapi/linux/nvme_ioctl.h @@ -68,15 +68,18 @@ struct nvme_passthru_cmd64 { __u32 timeout_ms; __u32 rsvd2; __u64 result; }; +/* struct nvme_uring_cmd flags field bits */ +#define NVME_URING_CMD_FIXED_METADATA (1U << 0) + /* same as struct nvme_passthru_cmd64, minus the 8b result field */ struct nvme_uring_cmd { __u8 opcode; __u8 flags; - __u16 rsvd1; + __u16 metadata_buf_index; __u32 nsid; __u32 cdw2; __u32 cdw3; __u64 metadata; __u64 addr; -- 2.55.0