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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 A4F9CEB64D0 for ; Tue, 13 Jun 2023 17:31:52 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1405010E05E; Tue, 13 Jun 2023 17:31:52 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id E083010E05E for ; Tue, 13 Jun 2023 17:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1686677510; 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=UFob1aFAu0uRDZrX0tACTzFE1GhOsHEDLUDxSxQ/iS8=; b=TN5Nd19SuKZZnB6czUSvXLQ8QvtyesX6rVr9mTS5UNPpmoGAvWbJ7z74dLh4SEIyVRu7at qqdhueTIOms00M0TrAxWtRSDxVXGbTVxm4lAT5E7uoKSH4cqQZB79TXEBoTNl0MW4xbcvv t7PTU6RrbViAP5Cjv12bpefOx25fY2U= Received: from mail-io1-f71.google.com (mail-io1-f71.google.com [209.85.166.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-456-QTbbLrL8MlG9XhJ6N2QJBg-1; Tue, 13 Jun 2023 13:31:48 -0400 X-MC-Unique: QTbbLrL8MlG9XhJ6N2QJBg-1 Received: by mail-io1-f71.google.com with SMTP id ca18e2360f4ac-7748b80141aso624648839f.0 for ; Tue, 13 Jun 2023 10:31:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686677507; x=1689269507; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=UFob1aFAu0uRDZrX0tACTzFE1GhOsHEDLUDxSxQ/iS8=; b=WGe4kDKyOJ+4h7Bi9bQCoCXBdOezsv7hnHMGSoNlLQio5D/YUKUaAa4l1bXtvNXfio 0+EHAqQUACVbS3T2eE2G+sHpCpTDcFDepVAJExTgJhAUZCUEXEkt/PHjUreV/rm9x+nI aTbesOwsXvKnKWHCuESDzYitA41ae1Lko3T5oixbcTKj5oStGEgFq08971jLaH4L9xgF ptuKr0UNeGg+Ib23aT981JUX3njYfuIheJTmzWCbwI8uRuFfTCGTrAEMdvcwG6jVqyoI T1x3pykXRBq1kcFszngk71Mcli0k8pi6XmBFZL/hbP0pYYAGJ4JjdT7oXtqc4ZTX02Al 3sLQ== X-Gm-Message-State: AC+VfDzYBMagyQuxuXXj+7DHmpyGD4w1o9GMw4M6ngktdVvZRU6dTowB btE/cZGoTxyr5p3g2Y7A6qCJPw/yWwyAu+L6p0SIU4PxK55MMi4NLEbr7REk80/wVEQ7ailhVo7 PkvIT0co9cVEjtL5ZWecoCyGFTvMv X-Received: by 2002:a6b:6611:0:b0:774:ae01:fe1a with SMTP id a17-20020a6b6611000000b00774ae01fe1amr11606439ioc.7.1686677507012; Tue, 13 Jun 2023 10:31:47 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ6bJFfYsjTQdozyUeq9/qeGnMAlrvVCxaIfEt3FiroYG03nbc7MFTmdssUxFLgFVi603YCgtg== X-Received: by 2002:a6b:6611:0:b0:774:ae01:fe1a with SMTP id a17-20020a6b6611000000b00774ae01fe1amr11606418ioc.7.1686677506733; Tue, 13 Jun 2023 10:31:46 -0700 (PDT) Received: from redhat.com ([38.15.36.239]) by smtp.gmail.com with ESMTPSA id z3-20020a5ec903000000b0077ac811b20dsm3980818iol.38.2023.06.13.10.31.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Jun 2023 10:31:46 -0700 (PDT) Date: Tue, 13 Jun 2023 11:31:45 -0600 From: Alex Williamson To: Jason Gunthorpe Message-ID: <20230613113145.66b02d0f.alex.williamson@redhat.com> In-Reply-To: References: <20230602121653.80017-1-yi.l.liu@intel.com> <20230602121653.80017-8-yi.l.liu@intel.com> <20230612155210.5fd3579f.alex.williamson@redhat.com> <20230613081647.740f5217.alex.williamson@redhat.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.35; x86_64-redhat-linux-gnu) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Intel-gfx] [PATCH v12 07/24] vfio: Block device access via device fd until device is opened X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "mjrosato@linux.ibm.com" , "jasowang@redhat.com" , "Hao, Xudong" , "Duan, Zhenzhong" , "peterx@redhat.com" , "Xu, Terrence" , "chao.p.peng@linux.intel.com" , "linux-s390@vger.kernel.org" , "Liu, Yi L" , "kvm@vger.kernel.org" , "lulu@redhat.com" , "Jiang, Yanting" , "joro@8bytes.org" , "nicolinc@nvidia.com" , "Tian, Kevin" , "Zhao, Yan Y" , "intel-gfx@lists.freedesktop.org" , "eric.auger@redhat.com" , "intel-gvt-dev@lists.freedesktop.org" , "yi.y.sun@linux.intel.com" , "clegoate@redhat.com" , "cohuck@redhat.com" , "shameerali.kolothum.thodi@huawei.com" , "suravee.suthikulpanit@amd.com" , "robin.murphy@arm.com" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, 13 Jun 2023 14:19:17 -0300 Jason Gunthorpe wrote: > On Tue, Jun 13, 2023 at 08:16:47AM -0600, Alex Williamson wrote: > > > > Not quite get why bit field is going to be incompatible with smp > > > lockless operations. Could you elaborate a bit? And should I define > > > the access_granted as u8 or "u8:1"? > > > > Perhaps FUD on my part, but load-acquire type operations have specific > > semantics and it's not clear to me that they interest with compiler > > generated bit operations. Thanks, > > They won't compile if you target bit ops, you can't take the address > of a bitfield. Yup, that's what I was assuming but was too lazy to prove it. Thanks, Alex