From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DCBA115B135; Thu, 10 Apr 2025 15:16:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744298163; cv=none; b=b/9O2qFhQlunX27UxmWAGstWOTmhtc13LHhV2yyDhDfpMz7BOA9YLnr+we8ZqY9hO2SyqIK7wXg3Y/fC0eeGxJ30dKBr3xoq8R/kwqEuObpBNRU1AOIXZ+Z5fjdCqv95dccKOeZ46GJHiT/hoGI3tmrXhXwhQSgT9fJMerAJhpk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744298163; c=relaxed/simple; bh=FJiKHY0yXYvYpnwTi6b4QY4wSVLzbkccdNokb8K2uZM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=snCZJ9I/aHDcMjrS7VsTzv98j0ny5jfJj0i26N9kmJzfQOTX3vs0RBK7vAN/rqsVeWlH7254WoREOhcNPovxqsiYdmAq5s/mXQGwIgx552W8zHrd7rEGV+cRMUC5MKLOpFG6y9+Yqux9+cF+z1byt3BBSpCZ7yW/Scyh8KaYSo8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=pPUwqlOB; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="pPUwqlOB" Received: from [10.137.184.60] (unknown [131.107.159.188]) by linux.microsoft.com (Postfix) with ESMTPSA id EA497203B86C; Thu, 10 Apr 2025 08:16:00 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com EA497203B86C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1744298161; bh=b/USx7FyrAAP0KVFJIR3S9nGQoNXd7rpnvG6sRwEcjk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=pPUwqlOBrIErhRnMenQuuETY6McFAU1X0L10gqqB+/k7VCThivMB270N9MVPVqKZv OKxIXSvIKMZxOqZulERNSc4wZJRTLL80Ml0pDUeMCwWwOhmkq4niN8+MWNU6gCLoNP iRC71M6wjwxVnS1zZO8WpZAJaxORmPm0mctceOLU= Message-ID: Date: Thu, 10 Apr 2025 08:16:00 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH hyperv-next 5/6] arch, drivers: Add device struct bitfield to not bounce-buffer To: Christoph Hellwig Cc: Robin Murphy , aleksander.lobakin@intel.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, catalin.marinas@arm.com, corbet@lwn.net, dakr@kernel.org, dan.j.williams@intel.com, dave.hansen@linux.intel.com, decui@microsoft.com, gregkh@linuxfoundation.org, haiyangz@microsoft.com, hpa@zytor.com, James.Bottomley@HansenPartnership.com, Jonathan.Cameron@huawei.com, kys@microsoft.com, leon@kernel.org, lukas@wunner.de, luto@kernel.org, m.szyprowski@samsung.com, martin.petersen@oracle.com, mingo@redhat.com, peterz@infradead.org, quic_zijuhu@quicinc.com, tglx@linutronix.de, wei.liu@kernel.org, will@kernel.org, iommu@lists.linux.dev, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, x86@kernel.org, apais@microsoft.com, benhill@microsoft.com, bperkins@microsoft.com, sunilmut@microsoft.com, Suzuki K Poulose References: <20250409000835.285105-1-romank@linux.microsoft.com> <20250409000835.285105-6-romank@linux.microsoft.com> <0eb87302-fae8-4708-aaf8-d16e836e727f@arm.com> <0ab2849a-5c03-4a8c-891e-3cb89b20b0e4@linux.microsoft.com> <20250410072150.GA32563@lst.de> Content-Language: en-US From: Roman Kisel In-Reply-To: <20250410072150.GA32563@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 4/10/2025 12:21 AM, Christoph Hellwig wrote: > On Wed, Apr 09, 2025 at 09:44:03AM -0700, Roman Kisel wrote: >> Do you feel this is shoehorned in `struct device`? I couldn't find an >> appropriate private (== opaque pointer) part in the structure to store >> that bit (`struct device_private` wouldn't fit the bill) and looked like >> adding it to the struct itself would do no harm. However, my read of the >> room is that folks see that as dubious :) > > We'll need per-device information. But it is much higher level than a > need bounce buffer flag. > I see, thanks for the explanation! -- Thank you, Roman