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 A2D10CCA470 for ; Tue, 7 Oct 2025 18:36:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v6CXK-000664-Qk; Tue, 07 Oct 2025 14:35:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v6CWn-0005oV-Ax for qemu-devel@nongnu.org; Tue, 07 Oct 2025 14:35:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v6CWf-0002pz-3Z for qemu-devel@nongnu.org; Tue, 07 Oct 2025 14:35:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1759862103; 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=oT0Pgap99n2+YSNINo4XgcnXxn2KZv6jwWIxQ2bC8+o=; b=apbbXmHGW8c/6qDeMEeO8T4NVAvbjV4CbIuG8YZzRZJYzhhsfdJ8ayUhCaDv5xCbgCSxVu 59Pi5C35qO1JiMtY2K15Y2sZv6zaw4k08Tjcfmsb3sGTFTTImOzoSi7b6KGMxTKURx0R1r NSm6vjp+cjCI3pLyPGgwmirxBPGv3mA= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-304-o-r2Azk3MUSfXtCvf58x8Q-1; Tue, 07 Oct 2025 14:35:00 -0400 X-MC-Unique: o-r2Azk3MUSfXtCvf58x8Q-1 X-Mimecast-MFC-AGG-ID: o-r2Azk3MUSfXtCvf58x8Q_1759862099 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C070F19560BA; Tue, 7 Oct 2025 18:34:59 +0000 (UTC) Received: from localhost (unknown [10.2.16.87]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 242CF30002C6; Tue, 7 Oct 2025 18:34:58 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Eric Blake , qemu-block@nongnu.org, Hanna Reitz , Stefan Hajnoczi , Yingshun Cui Subject: [PATCH v2 4/5] block: update inserted/removed nodes from BlockRAMRegistrar Date: Tue, 7 Oct 2025 14:34:46 -0400 Message-ID: <20251007183447.93120-5-stefanha@redhat.com> In-Reply-To: <20251007183447.93120-1-stefanha@redhat.com> References: <20251007183447.93120-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.422, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-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-bounces+qemu-devel=archiver.kernel.org@nongnu.org BlockRAMRegistrar ensures that RAMBlocks are registered with BlockDriverStates. This is essential for vdpa-blk because they need to know the memory mappings of I/O buffers. However, BlockRAMRegistrar is currently unaware of changes to the block graph and newly inserted nodes have no RAMBlocks registered. Use the new blk_add_attach_notifier() and blk_add_detach_notifier() APIs to bring nodes up to speed when the graph changes. This fixes vdpa-blk across mirror and other operations that modify the block graph. Previously I/O would not succeed after a new node was inserted due to missing memory mappings. Buglink: https://issues.redhat.com/browse/RHEL-88175 Reported-by: Yingshun Cui Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake --- include/system/block-ram-registrar.h | 2 + block/block-ram-registrar.c | 61 +++++++++++++++++++++++++++- 2 files changed, 61 insertions(+), 2 deletions(-) diff --git a/include/system/block-ram-registrar.h b/include/system/block-ram-registrar.h index 76c157bd54..292c197d1c 100644 --- a/include/system/block-ram-registrar.h +++ b/include/system/block-ram-registrar.h @@ -22,6 +22,8 @@ typedef struct { BlockBackend *blk; RAMBlockNotifier ram_block_notifier; + Notifier blk_attach_notifier; + Notifier blk_detach_notifier; bool ok; } BlockRAMRegistrar; diff --git a/block/block-ram-registrar.c b/block/block-ram-registrar.c index d5b84667a1..2d334c5655 100644 --- a/block/block-ram-registrar.c +++ b/block/block-ram-registrar.c @@ -7,7 +7,9 @@ #include "qemu/osdep.h" #include "system/block-backend.h" #include "system/block-ram-registrar.h" +#include "system/ramblock.h" #include "qapi/error.h" +#include "trace.h" static void ram_block_added(RAMBlockNotifier *n, void *host, size_t size, size_t max_size) @@ -22,8 +24,8 @@ static void ram_block_added(RAMBlockNotifier *n, void *host, size_t size, if (!blk_register_buf(r->blk, host, max_size, &err)) { error_report_err(err); - ram_block_notifier_remove(n); - r->ok = false; + blk_ram_registrar_destroy(r); + return; } } @@ -35,6 +37,50 @@ static void ram_block_removed(RAMBlockNotifier *n, void *host, size_t size, blk_unregister_buf(r->blk, host, max_size); } +static void blk_attached(Notifier *n, void *data) +{ + BlockRAMRegistrar *r = + container_of(n, BlockRAMRegistrar, blk_attach_notifier); + BlockBackendAttachDetachArgs *args = data; + BlockDriverState *bs = args->bs; + Error *err = NULL; + + WITH_RCU_READ_LOCK_GUARD() { + RAMBlock *rb; + + RAMBLOCK_FOREACH(rb) { + ram_addr_t max_size = qemu_ram_get_max_length(rb); + void *host = qemu_ram_get_host_addr(rb); + + if (!bdrv_register_buf(bs, host, max_size, &err)) { + goto err; + } + } + } + + return; + +err: + error_report_err(err); + blk_ram_registrar_destroy(r); +} + +static void blk_detached(Notifier *n, void *data) +{ + BlockBackendAttachDetachArgs *args = data; + BlockDriverState *bs = args->bs; + RAMBlock *rb; + + RCU_READ_LOCK_GUARD(); + + RAMBLOCK_FOREACH(rb) { + ram_addr_t max_size = qemu_ram_get_max_length(rb); + void *host = qemu_ram_get_host_addr(rb); + + bdrv_unregister_buf(bs, host, max_size); + } +} + void blk_ram_registrar_init(BlockRAMRegistrar *r, BlockBackend *blk) { r->blk = blk; @@ -47,14 +93,25 @@ void blk_ram_registrar_init(BlockRAMRegistrar *r, BlockBackend *blk) * value that does not change across resize. */ }; + r->blk_attach_notifier = (Notifier){ + .notify = blk_attached, + }; + r->blk_detach_notifier = (Notifier){ + .notify = blk_detached, + }; r->ok = true; ram_block_notifier_add(&r->ram_block_notifier); + blk_add_attach_notifier(blk, &r->blk_attach_notifier); + blk_add_detach_notifier(blk, &r->blk_detach_notifier); } void blk_ram_registrar_destroy(BlockRAMRegistrar *r) { if (r->ok) { + notifier_remove(&r->blk_detach_notifier); + notifier_remove(&r->blk_attach_notifier); ram_block_notifier_remove(&r->ram_block_notifier); + r->ok = false; } } -- 2.51.0