From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 33F96C433F5 for ; Thu, 6 Oct 2022 21:40:23 +0000 (UTC) Received: from localhost ([::1]:43182 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ogYbO-00039s-At for qemu-devel@archiver.kernel.org; Thu, 06 Oct 2022 17:40:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53718) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ogYWf-00039V-3i for qemu-devel@nongnu.org; Thu, 06 Oct 2022 17:35:31 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:26521) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ogYWd-0006mg-3N for qemu-devel@nongnu.org; Thu, 06 Oct 2022 17:35:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1665092126; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UP9I4eVyXrRvYhfhv/f4mIPWi1FXnAnj3msdPoFE7J4=; b=YG8nDQagc8c4qy2ekscXPQXVwskjU5lWxp/WeMWQLANFxbjdD//OsiPzMhZ5/03dWSR2Es H6y4m5SUoQDgjftLQNcC/41QWFY3K8UMO/xC3dR9PqYvtAPf4oIbLaWfzgNU4dzNj3XJqi ZWMR5HQmh6d0389MZM+n/++P6K9HwYo= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-653-zFk7Cf8mMLmuBiQy46_XtA-1; Thu, 06 Oct 2022 17:35:22 -0400 X-MC-Unique: zFk7Cf8mMLmuBiQy46_XtA-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 95FC1185A794; Thu, 6 Oct 2022 21:35:21 +0000 (UTC) Received: from localhost (unknown [10.39.193.119]) by smtp.corp.redhat.com (Postfix) with ESMTP id EF7E0535939; Thu, 6 Oct 2022 21:35:20 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Yanan Wang , sgarzare@redhat.com, "Richard W.M. Jones" , Fam Zheng , Hanna Reitz , David Hildenbrand , integration@gluster.org, qemu-block@nongnu.org, Vladimir Sementsov-Ogievskiy , Paolo Bonzini , Kevin Wolf , afaria@redhat.com, Richard Henderson , Eric Blake , "Michael S. Tsirkin" , Thomas Huth , Xie Changlong , John Snow , Eduardo Habkost , Jeff Cody , Stefan Hajnoczi , "Denis V. Lunev" , Markus Armbruster , Laurent Vivier , Peter Xu , Raphael Norwitz , Marcel Apfelbaum , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Wen Congyang Subject: [PATCH v6 04/13] block: pass size to bdrv_unregister_buf() Date: Thu, 6 Oct 2022 17:34:58 -0400 Message-Id: <20221006213507.645402-5-stefanha@redhat.com> In-Reply-To: <20221006213507.645402-1-stefanha@redhat.com> References: <20221006213507.645402-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The only implementor of bdrv_register_buf() is block/nvme.c, where the size is not needed when unregistering a buffer. This is because util/vfio-helpers.c can look up mappings by address. Future block drivers that implement bdrv_register_buf() may not be able to do their job given only the buffer address. Add a size argument to bdrv_unregister_buf(). Also document the assumptions about bdrv_register_buf()/bdrv_unregister_buf() calls. The same values that were given to bdrv_register_buf() must be given to bdrv_unregister_buf(). gcc 11.2.1 emits a spurious warning that img_bench()'s buf_size local variable might be uninitialized, so it's necessary to silence the compiler. Signed-off-by: Stefan Hajnoczi --- include/block/block-global-state.h | 5 ++++- include/block/block_int-common.h | 2 +- include/sysemu/block-backend-global-state.h | 2 +- block/block-backend.c | 4 ++-- block/io.c | 6 +++--- block/nvme.c | 2 +- qemu-img.c | 4 ++-- 7 files changed, 14 insertions(+), 11 deletions(-) diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h index 21265e3966..7901f35863 100644 --- a/include/block/block-global-state.h +++ b/include/block/block-global-state.h @@ -243,9 +243,12 @@ void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); * Register/unregister a buffer for I/O. For example, VFIO drivers are * interested to know the memory areas that would later be used for I/O, so * that they can prepare IOMMU mapping etc., to get better performance. + * + * Buffers must not overlap and they must be unregistered with the same values that they were registered with. */ void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size); -void bdrv_unregister_buf(BlockDriverState *bs, void *host); +void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size); void bdrv_cancel_in_flight(BlockDriverState *bs); diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 8947abab76..b7a7cbd3a5 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -435,7 +435,7 @@ struct BlockDriver { * DMA mapping for hot buffers. */ void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size); - void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host); + void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host, size_t size); /* * This field is modified only under the BQL, and is part of diff --git a/include/sysemu/block-backend-global-state.h b/include/sysemu/block-backend-global-state.h index 415f0c91d7..97f7dad2c3 100644 --- a/include/sysemu/block-backend-global-state.h +++ b/include/sysemu/block-backend-global-state.h @@ -107,7 +107,7 @@ void blk_io_limits_update_group(BlockBackend *blk, const char *group); void blk_set_force_allow_inactivate(BlockBackend *blk); void blk_register_buf(BlockBackend *blk, void *host, size_t size); -void blk_unregister_buf(BlockBackend *blk, void *host); +void blk_unregister_buf(BlockBackend *blk, void *host, size_t size); const BdrvChild *blk_root(BlockBackend *blk); diff --git a/block/block-backend.c b/block/block-backend.c index d4a5df2ac2..99141f8f06 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -2551,10 +2551,10 @@ void blk_register_buf(BlockBackend *blk, void *host, size_t size) bdrv_register_buf(blk_bs(blk), host, size); } -void blk_unregister_buf(BlockBackend *blk, void *host) +void blk_unregister_buf(BlockBackend *blk, void *host, size_t size) { GLOBAL_STATE_CODE(); - bdrv_unregister_buf(blk_bs(blk), host); + bdrv_unregister_buf(blk_bs(blk), host, size); } int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in, diff --git a/block/io.c b/block/io.c index c3200bcdff..fa34e6c61d 100644 --- a/block/io.c +++ b/block/io.c @@ -3275,16 +3275,16 @@ void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size) } } -void bdrv_unregister_buf(BlockDriverState *bs, void *host) +void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size) { BdrvChild *child; GLOBAL_STATE_CODE(); if (bs->drv && bs->drv->bdrv_unregister_buf) { - bs->drv->bdrv_unregister_buf(bs, host); + bs->drv->bdrv_unregister_buf(bs, host, size); } QLIST_FOREACH(child, &bs->children, next) { - bdrv_unregister_buf(child->bs, host); + bdrv_unregister_buf(child->bs, host, size); } } diff --git a/block/nvme.c b/block/nvme.c index 01fb28aa63..696502acea 100644 --- a/block/nvme.c +++ b/block/nvme.c @@ -1592,7 +1592,7 @@ static void nvme_register_buf(BlockDriverState *bs, void *host, size_t size) } } -static void nvme_unregister_buf(BlockDriverState *bs, void *host) +static void nvme_unregister_buf(BlockDriverState *bs, void *host, size_t size) { BDRVNVMeState *s = bs->opaque; diff --git a/qemu-img.c b/qemu-img.c index cab9776f42..1dd5efe840 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -4368,7 +4368,7 @@ static int img_bench(int argc, char **argv) struct timeval t1, t2; int i; bool force_share = false; - size_t buf_size; + size_t buf_size = 0; for (;;) { static const struct option long_options[] = { @@ -4590,7 +4590,7 @@ static int img_bench(int argc, char **argv) out: if (data.buf) { - blk_unregister_buf(blk, data.buf); + blk_unregister_buf(blk, data.buf, buf_size); } qemu_vfree(data.buf); blk_unref(blk); -- 2.37.3