From patchwork Thu Dec 17 16:56:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 11980229 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20D09C2BBCD for ; Thu, 17 Dec 2020 16:59:45 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8D809233A0 for ; Thu, 17 Dec 2020 16:59:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D809233A0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:49724 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kpwcx-00051V-Mh for qemu-devel@archiver.kernel.org; Thu, 17 Dec 2020 11:59:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34132) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kpwa8-0003A0-GO for qemu-devel@nongnu.org; Thu, 17 Dec 2020 11:56:48 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:50591) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kpwa0-00030H-Ko for qemu-devel@nongnu.org; Thu, 17 Dec 2020 11:56:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608224196; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lAF4AMDHh0B6zN8Q97spxe57FkcIvd7Tu2zQJxqa9tc=; b=ZkRuMCu2laEls51IGTGBFnZ1yCSf7jKFAb2z3yNzn02ZTx8kM7UIiepCkjSLETAoF93cd6 cGV6t8xFJhvA2IAy7LdIfts5deDS9H+E2Q6ohABN0TZmUgPHhue2uPOUYU1avGa6AKmjw0 1wWjBnwG8eAWU+d2yV8BIEgPioKQFHk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-178-PFnpIJpBNrewaaVPoYQsmA-1; Thu, 17 Dec 2020 11:56:35 -0500 X-MC-Unique: PFnpIJpBNrewaaVPoYQsmA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7DB53101AFBA; Thu, 17 Dec 2020 16:56:33 +0000 (UTC) Received: from localhost.localdomain (unknown [10.35.206.213]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0C7C41F055; Thu, 17 Dec 2020 16:56:29 +0000 (UTC) From: Maxim Levitsky To: qemu-devel@nongnu.org Subject: [PATCH v3 3/5] block: add max_ioctl_transfer to BlockLimits Date: Thu, 17 Dec 2020 18:56:10 +0200 Message-Id: <20201217165612.942849-4-mlevitsk@redhat.com> In-Reply-To: <20201217165612.942849-1-mlevitsk@redhat.com> References: <20201217165612.942849-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mlevitsk@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=63.128.21.124; envelope-from=mlevitsk@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , Ronnie Sahlberg , qemu-block@nongnu.org, Peter Lieven , Tom Yan , Stefan Hajnoczi , Paolo Bonzini , Maxim Levitsky , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Maximum transfer size when accessing a kernel block device is only relevant when using SCSI passthrough (SG_IO ioctl) since only in this case the requests are passed directly to underlying hardware with no pre-processing. Same is true when using /dev/sg* character devices (which only support SG_IO) Therefore split the block driver's advertized max transfer size by the regular max transfer size, and the max transfer size for SCSI passthrough (the new max_ioctl_transfer field) In the next patch, the qemu block drivers that support SCSI passthrough will set the max_ioctl_transfer field, and simultaneously, the block devices that implement scsi passthrough will switch to 'blk_get_max_ioctl_transfer' to query and to pass it to the guest. Signed-off-by: Maxim Levitsky --- block/block-backend.c | 12 ++++++++++++ block/io.c | 2 ++ include/block/block_int.h | 4 ++++ include/sysemu/block-backend.h | 1 + 4 files changed, 19 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index ce78d30794..c1d149a755 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1938,6 +1938,18 @@ uint32_t blk_get_max_transfer(BlockBackend *blk) return MIN_NON_ZERO(max, INT_MAX); } +/* Returns the maximum transfer length, for SCSI passthrough */ +uint32_t blk_get_max_ioctl_transfer(BlockBackend *blk) +{ + BlockDriverState *bs = blk_bs(blk); + uint32_t max = 0; + + if (bs) { + max = bs->bl.max_ioctl_transfer; + } + return MIN_NON_ZERO(max, INT_MAX); +} + int blk_get_max_iov(BlockBackend *blk) { return blk->root->bs->bl.max_iov; diff --git a/block/io.c b/block/io.c index 24205f5168..ac5aea435e 100644 --- a/block/io.c +++ b/block/io.c @@ -126,6 +126,8 @@ static void bdrv_merge_limits(BlockLimits *dst, const BlockLimits *src) { dst->opt_transfer = MAX(dst->opt_transfer, src->opt_transfer); dst->max_transfer = MIN_NON_ZERO(dst->max_transfer, src->max_transfer); + dst->max_ioctl_transfer = MIN_NON_ZERO(dst->max_ioctl_transfer, + src->max_ioctl_transfer); dst->opt_mem_alignment = MAX(dst->opt_mem_alignment, src->opt_mem_alignment); dst->min_mem_alignment = MAX(dst->min_mem_alignment, diff --git a/include/block/block_int.h b/include/block/block_int.h index 1eeafc118c..c59b0aefc4 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -686,6 +686,10 @@ typedef struct BlockLimits { * clamped down. */ uint32_t max_transfer; + /* Maximal transfer length for SCSI passthrough (ioctl interface) */ + uint32_t max_ioctl_transfer; + + /* memory alignment, in bytes so that no bounce buffer is needed */ size_t min_mem_alignment; diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 8203d7f6f9..b019a37b7a 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -203,6 +203,7 @@ void blk_eject(BlockBackend *blk, bool eject_flag); int blk_get_flags(BlockBackend *blk); uint32_t blk_get_request_alignment(BlockBackend *blk); uint32_t blk_get_max_transfer(BlockBackend *blk); +uint32_t blk_get_max_ioctl_transfer(BlockBackend *blk); int blk_get_max_iov(BlockBackend *blk); void blk_set_guest_block_size(BlockBackend *blk, int align); void *blk_try_blockalign(BlockBackend *blk, size_t size);