From nobody Tue May 13 12:45:56 2025 Delivered-To: importer2@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1675354154; cv=none; d=zohomail.com; s=zohoarc; b=fqaC5WIar17+udLWN/Bjm2om6C89DDPE8UboFGykrAaVs/zti1Z4TpTXTNz7JRFSCYAPCK5A3KUxZhzaql4TPrqSFtoPBa+tUWO2sJ2YNqQ28LqOqK1oJS1+YRmwnhqpzZu7KQBhXbEu2PWJshft2c++Iv2dzZgjkNUtIbVRDyk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1675354154; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=6lIg7aqLoDZba0OtgiOTBlqeFrJWsZnu9N17z0NU7N0=; b=Nl5rZwaEDhIqfKjghoh3qTSa1hTZ83NFNqomTyqyne/MsWm3fLM9bpJDQz99EZXyD92qmaN5eJu+MY/owsTB+lw2INplEJ5FL7e9350XNyykMuo00UdKp1BWvXcj64ePySKp4yLszNU3yFmYHnDP4fy/hsLSvygC3G5LUbntdyw= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1675354154470733.0845421504922; Thu, 2 Feb 2023 08:09:14 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pNc7l-0007iu-Tt; Thu, 02 Feb 2023 11:07:45 -0500 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 1pNc7j-0007bl-Ez for qemu-devel@nongnu.org; Thu, 02 Feb 2023 11:07:43 -0500 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 1pNc7h-00057M-Sl for qemu-devel@nongnu.org; Thu, 02 Feb 2023 11:07:43 -0500 Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-528-hAFacFWqNEqrPJ9XDlOaeQ-1; Thu, 02 Feb 2023 11:07:37 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3852C3847992; Thu, 2 Feb 2023 16:07:36 +0000 (UTC) Received: from secure.mitica (unknown [10.39.192.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9682951E5; Thu, 2 Feb 2023 16:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675354061; 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=6lIg7aqLoDZba0OtgiOTBlqeFrJWsZnu9N17z0NU7N0=; b=AUn4G583BF9nMoIWbCqVhS6LXGFm30SSTPWMMSvAPjLVTRLRP5tioNMQxFNlL/ZdDpLR+s Iva571eiOrq1bPMh8GuGffa/59gTJosffDhC5Pudd1IYqxoE8mmjXUcEgmQlOW7GzPlsNn EJn/5KUWsMsjOMjHHUB9k1Y8xgBc9Xk= X-MC-Unique: hAFacFWqNEqrPJ9XDlOaeQ-1 From: Juan Quintela To: qemu-devel@nongnu.org Cc: Richard Henderson , "Michael S. Tsirkin" , Laurent Vivier , Ilya Leoshkevich , Halil Pasic , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Coiby Xu , Eric Farman , Alex Williamson , Christian Borntraeger , Stefan Hajnoczi , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Stefan Berger , Eric Blake , Eduardo Habkost , "Dr. David Alan Gilbert" , Thomas Huth , David Hildenbrand , Marcel Apfelbaum , John Snow , Yanan Wang , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, Paolo Bonzini , Juan Quintela , Fam Zheng , qemu-s390x@nongnu.org, Peter Xu Subject: [PULL 10/26] migration/ram: Rely on used_length for uffd_change_protection() Date: Thu, 2 Feb 2023 17:06:24 +0100 Message-Id: <20230202160640.2300-11-quintela@redhat.com> In-Reply-To: <20230202160640.2300-1-quintela@redhat.com> References: <20230202160640.2300-1-quintela@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.133.124; envelope-from=quintela@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_H2=-0.001, 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+importer2=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer2=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1675354155528100001 Content-Type: text/plain; charset="utf-8" From: David Hildenbrand ram_mig_ram_block_resized() will abort migration (including background snapshots) when resizing a RAMBlock. ram_block_populate_read() will only populate RAM up to used_length, so at least for anonymous memory protecting everything between used_length and max_length won't actually be protected and is just a NOP. So let's only protect everything up to used_length. Note: it still makes sense to register uffd-wp for max_length, such that RAM_UF_WRITEPROTECT is independent of a changing used_length. Reviewed-by: Peter Xu Reviewed-by: Juan Quintela Signed-off-by: David Hildenbrand Signed-off-by: Juan Quintela --- migration/ram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index efaae07dd8..a6956c9e7d 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1901,7 +1901,7 @@ int ram_write_tracking_start(void) =20 /* Apply UFFD write protection to the block memory range */ if (uffd_change_protection(rs->uffdio_fd, block->host, - block->max_length, true, false)) { + block->used_length, true, false)) { goto fail; } =20 --=20 2.39.1