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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6442BC433E2 for ; Wed, 2 Sep 2020 23:08:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3308520767 for ; Wed, 2 Sep 2020 23:08:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726794AbgIBXIe (ORCPT ); Wed, 2 Sep 2020 19:08:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726586AbgIBXIe (ORCPT ); Wed, 2 Sep 2020 19:08:34 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0E18C061244 for ; Wed, 2 Sep 2020 16:08:33 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 9A77D15746469; Wed, 2 Sep 2020 15:51:45 -0700 (PDT) Date: Wed, 02 Sep 2020 16:08:31 -0700 (PDT) Message-Id: <20200902.160831.2194160080454145229.davem@davemloft.net> To: awogbemila@google.com Cc: kuba@kernel.org, netdev@vger.kernel.org, csully@google.com, yangchun@google.com Subject: Re: [PATCH net-next v2 4/9] gve: Add support for dma_mask register From: David Miller In-Reply-To: References: <20200901215149.2685117-5-awogbemila@google.com> <20200901173410.5ce6a087@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [2620:137:e000::1:9]); Wed, 02 Sep 2020 15:51:45 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: David Awogbemila Date: Wed, 2 Sep 2020 11:42:37 -0700 > I don't think there is a specific 24-bit device in mind here, only > that we have seen 32-bit addressing use cases where the guest ran out > of SWIOTLB space and restricting to GFP_DMA32 helped.. so we thought > it would be natural for the driver to handle the 24 bit case in case > it ever came along. You should add such support when the situation presents itself, rather than prematurely like this. Thank you.