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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 D8CE7C10F14 for ; Wed, 10 Apr 2019 12:34:18 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A386B217D7 for ; Wed, 10 Apr 2019 12:34:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="bwTr9SpD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A386B217D7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=QwZp5jBIJbjwkDV2YARnm2DcQR/G5NKASr8vkbi78ds=; b=bwTr9SpDX4pX5V HqjTNwFZfKJkbI/20aKO98sr89UFTJ/Z+hgYxW5IlyI21cBTQwpl4M+ix6MOLhEW7hUuT8XlAWm2M Pgh7Vs2FmDnqzJlNQA6ozlyIyJhIJPm1KEkllkeJj4zBBUyEbGDQkSYiarlXKsy3zG+uZX/2B9JaO Gs+PAktk60UOAubSO12gq+qrIDJFTCVDQxOeqR8MudNUM1D0RSW4VDWI9OzDGUZhP3qDhBCULD4nR 5UhZwDxd19ehFxLtpuV0gdx/ywIsfj5fQqobPohrsjcDNb/wuXAtI7AUpaUEkBH4c2HDg2MNsuIbm 2bKdqBV2fzShdueaQLFg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hECQj-00070b-CH; Wed, 10 Apr 2019 12:34:17 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hECQg-00070B-MX for linux-arm-kernel@lists.infradead.org; Wed, 10 Apr 2019 12:34:15 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5201AA78; Wed, 10 Apr 2019 05:34:11 -0700 (PDT) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6194F3F59C; Wed, 10 Apr 2019 05:34:09 -0700 (PDT) Date: Wed, 10 Apr 2019 13:34:06 +0100 From: Dave Martin To: Andrew Jones Subject: Re: [PATCH v7 27/27] KVM: arm64/sve: Document KVM API extensions for SVE Message-ID: <20190410123405.GG3567@e103592.cambridge.arm.com> References: <1553864452-15080-1-git-send-email-Dave.Martin@arm.com> <1553864452-15080-28-git-send-email-Dave.Martin@arm.com> <20190404210921.7xz6o56wietd77li@kamzik.brq.redhat.com> <20190405093617.GO3567@e103592.cambridge.arm.com> <20190405103937.quhaxxwkjjdxab6z@kamzik.brq.redhat.com> <20190405130007.GB3567@e103592.cambridge.arm.com> <20190405153804.qnw774e5bsudd2kn@kamzik.brq.redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190405153804.qnw774e5bsudd2kn@kamzik.brq.redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190410_053414_742721_A0582A57 X-CRM114-Status: GOOD ( 23.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Okamoto Takayuki , Christoffer Dall , Ard Biesheuvel , Marc Zyngier , Catalin Marinas , Will Deacon , Zhang Lei , Julien Grall , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 05, 2019 at 05:38:04PM +0200, Andrew Jones wrote: > On Fri, Apr 05, 2019 at 02:00:07PM +0100, Dave Martin wrote: > > On Fri, Apr 05, 2019 at 12:39:37PM +0200, Andrew Jones wrote: > > > On Fri, Apr 05, 2019 at 10:36:17AM +0100, Dave Martin wrote: > > > > On Thu, Apr 04, 2019 at 11:09:21PM +0200, Andrew Jones wrote: [...] > > > > > I'm still not sure about EPERM vs. ENOEXEC. > > > > > > > > There is no need to distinguish the two: this is just a generic "vcpu in > > > > wrong state for this to work" error. I can't think of another subsystem > > > > that uses ENOEXEC for this meaning, but it's established in KVM. > > > > > > > > If you can't see a reason why we would need these to be distinct > > > > errors (?) then I'm happy for this to be ENOEXEC for all cases. > > > > > > > > > > I do see some value in keeping them distinct. I think it's just the use > > > of EPERM specifically that bothers me, but I don't have that strong of > > > an opinion against its use either. So I'll just shut up :) > > > > In an earlier incarnation I had EBADFD, which does kind of mean the > > right thing. > > > > If there's not a clear way forward, I may leave this all as-is for now > > (but I'll remove the explicit documentation for KVM_{GET,SET}_ONE_REG > > error codes to give us more flexibility about this in the future, as > > discussed). > > > > Any objection? > > Nope. Let's do that. EBADFD doesn't sound good, because we're using the FD > without trouble before and even after we attempt these ioctls. I think > EBADFD would indicate that no future ioctl (or read,write) should be > expected to work. OK. I may also keep some of the error code documentation, but water it down a bit to make it clearer that the error codes are indicate and arm64-specifc. We can see how it looks when I have a series to post. Cheers ---Dave _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel