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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B49CC4332F for ; Wed, 16 Nov 2022 11:53:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233383AbiKPLxO (ORCPT ); Wed, 16 Nov 2022 06:53:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233144AbiKPLwg (ORCPT ); Wed, 16 Nov 2022 06:52:36 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EAE3E45EDA for ; Wed, 16 Nov 2022 03:42:21 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id AAC31B81CF8 for ; Wed, 16 Nov 2022 11:42:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC92BC43470; Wed, 16 Nov 2022 11:42:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1668598939; bh=9eMkKHxHguP0USa1SZGodEQEk/UP3sUe8VUBTS3NJ2Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vBTGVzfUtUW0US1GVjN/jUvNNmNHLPz4cYJuPHf6jd1+Xkcf55ckMErcbd2o2M7qk Eug1EQOG7XGolWNlyda4U7hTe3vLoyFlOadoQq3yG6M3K5C2EQI5bTzLNQdJNmGJ9u x1CeR+IzqAQXaAXl85qE1UaC3k8cJWadkJ8Z1X1w= Date: Wed, 16 Nov 2022 12:42:16 +0100 From: Greg Kroah-Hartman To: Andy Shevchenko Cc: linux-kernel@vger.kernel.org, Fei Li , "Rafael J. Wysocki" Subject: Re: [PATCH v4 1/1] virt: acrn: Mark the uuid field as unused Message-ID: References: <20221116092254.66234-1-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221116092254.66234-1-andriy.shevchenko@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 16, 2022 at 11:22:54AM +0200, Andy Shevchenko wrote: > After the commits for userspace (see Link tags below) the uuid field is > not being used in the ACRN code. Update kernel to reflect these changes. > I.e. we do the following: > - adding a comment explaining that it's not used anymore > - replacing the specific type by a raw buffer > - updating the example code accordingly > > The advertised field confused users and actually never been used. So > the wrong part here is that kernel puts something which userspace never > used and hence this may confuse a reader of this code. > > Link: https://github.com/projectacrn/acrn-hypervisor/commit/da0d24326ed6 > Link: https://github.com/projectacrn/acrn-hypervisor/commit/bb0327e70097 > Fixes: 5b06931d7f8b ("sample/acrn: Introduce a sample of HSM ioctl interface usage") > Fixes: 9c5137aedd11 ("virt: acrn: Introduce VM management interfaces") > Signed-off-by: Andy Shevchenko > Acked-by: Rafael J. Wysocki > --- > v4: added tag (Rafael), Cc'ed to Greg (missing in the previous version > by some reason) > v3: converted to Link tags (Rafael), explained what was wrong (Rafael) > v2: added tag (Fei) > > include/uapi/linux/acrn.h | 5 ++--- > samples/acrn/vm-sample.c | 3 --- > 2 files changed, 2 insertions(+), 6 deletions(-) > > diff --git a/include/uapi/linux/acrn.h b/include/uapi/linux/acrn.h > index ccf47ed92500..04fa83647ae5 100644 > --- a/include/uapi/linux/acrn.h > +++ b/include/uapi/linux/acrn.h > @@ -12,7 +12,6 @@ > #define _UAPI_ACRN_H > > #include > -#include > > #define ACRN_IO_REQUEST_MAX 16 > > @@ -186,7 +185,7 @@ struct acrn_ioreq_notify { > * @reserved0: Reserved and must be 0 > * @vcpu_num: Number of vCPU in the VM. Return from hypervisor. > * @reserved1: Reserved and must be 0 > - * @uuid: UUID of the VM. Pass to hypervisor directly. > + * @uuid: Reserved (used to be UUID of the VM) If it's reserved, then don't you need to check for 0? > * @vm_flag: Flag of the VM creating. Pass to hypervisor directly. > * @ioreq_buf: Service VM GPA of I/O request buffer. Pass to > * hypervisor directly. > @@ -198,7 +197,7 @@ struct acrn_vm_creation { > __u16 reserved0; > __u16 vcpu_num; > __u16 reserved1; > - guid_t uuid; > + __u8 uuid[16]; You just changed the type here, so what is that going to break in userspace that depended on this being of a structure type and now it's an array? And no other kernel changes needed? Shouldn't you warn if this field is set? thanks, greg k-h