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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]:46800 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kUk6O-0006Ui-BV for qemu-devel@archiver.kernel.org; Tue, 20 Oct 2020 01:22:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35714) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kUk3e-0004VH-4q for qemu-devel@nongnu.org; Tue, 20 Oct 2020 01:19:41 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:40102) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kUk3a-0000BA-G4 for qemu-devel@nongnu.org; Tue, 20 Oct 2020 01:19:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603171171; 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=taOzKHIxLq8lPduH4GToLxTo66KEDRLQ3aLHkNazjzA=; b=ViBGKmBi4beRN6yTJFTZCpT3pbG4xepofJGjhrgiUqsszizoWVOuARx2I1lNyFVLGNvMqm JNWfFaM/8C4SF3d2Sn54Pw3tRVoqm64+wwlVOfqUbzy8InG/ZWRrAbtpWcgZobDsVm5AoU bFngSL+Q911hitOxg0uR/xkOfOIEDko= 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-375-kaJj9idxO_WDIQmtCLnCiw-1; Tue, 20 Oct 2020 01:19:27 -0400 X-MC-Unique: kaJj9idxO_WDIQmtCLnCiw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 465051084C97; Tue, 20 Oct 2020 05:19:26 +0000 (UTC) Received: from thuth.remote.csb (ovpn-112-107.ams2.redhat.com [10.36.112.107]) by smtp.corp.redhat.com (Postfix) with ESMTP id 88F4D5C641; Tue, 20 Oct 2020 05:19:25 +0000 (UTC) Subject: Re: [PATCH v2 9/9] block: check availablity for preadv/pwritev on mac To: Joelle van Dyne References: <20201019013928.72770-1-j@getutm.app> <20201019013928.72770-10-j@getutm.app> <54ea1dc9-f4e5-7827-6d05-c574b8c411d1@redhat.com> From: Thomas Huth Message-ID: <8bebc004-5a63-8936-b8ef-d1bf68dbf220@redhat.com> Date: Tue, 20 Oct 2020 07:19:23 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=thuth@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=thuth@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/20 01:16:16 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] 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, NICE_REPLY_A=-0.001, 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: QEMU Developers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 20/10/2020 00.20, Joelle van Dyne wrote: > On Mon, Oct 19, 2020 at 1:27 AM Thomas Huth wrote: >> >> On 19/10/2020 03.39, Joelle van Dyne wrote: >>> From: osy >> >> That "From:" line looks wrong ... could you please fix the "Author" of your >> patches / your git config? > osy wrote the original changes. I joined the UTM project to help bring > the changes upstream with permission. However, they have agreed that > if required that we can use my name as the author. In any way, that "users.noreply.github.com" does not look like a valid e-mail address and should be replaced. >> >>> macOS 11/iOS 14 added preadv/pwritev APIs. Due to weak linking, configure >>> will succeed with CONFIG_PREADV even when targeting a lower OS version. We >>> therefore need to check at run time if we can actually use these APIs. >> >> That sounds like the wrong approach to me ... could you please try to fix >> the check in "configure" instead? E.g. by running compile_prog with >> "-Werror", so that the test fails if there is no valid prototype available? > It's not that simple. Xcode 11 and below (supporting macOS 10.15 and > below, iOS 13 and below, etc) does not have preadv/pwritev symbols > defined and would fail to compile. Xcode 12 (supporting macOS 11 and > below, iOS 14 and below, etc) have preadv/pwritev weakly defined so if > it runs on, for example, 10.15, it would abort. There is no way to > determine at compile time if you can use preadv/pwritev or not when > building with Xcode 12. The availability checks are Apple's preferred > way to handle this kind of situation (they discourage directly > checking if an API exists on a system). Ok, got it now, thanks for the detailed explanation! Thomas