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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 F3FF2C4360F for ; Fri, 5 Apr 2019 11:11:30 +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 BECA821738 for ; Fri, 5 Apr 2019 11:11:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TKje41Ci" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BECA821738 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=36sZCd7P6dBm9kU+5cyfZSjcWKe/NheE0XozlFpS1WQ=; b=TKje41CizjtgmE 0Tn2JSXM6mvcuSc+oMB2AP7wNLQWjENGTTdLT8eRa4D/YMtPLkpF9lYJ7TbXyzSDZrVEOhsXWGcQB AkIarQ0VmjcNpmssmHBsL7hCPMY7dHxFTDxB4M05W97jD+eLAYERAnSD3XZzoO10uK33UwhYAzrH4 cGwhjG5JfQ1w0e8BysXD2/Vd0pkyCqya7ws0atyq2Rnx3iGqS/hZ+4tkOqlmrtCzAJ+zvDk7pZ9/y spk+M3np+J95phhcksLDD8XcuXu+gyOj7Xyie70mRkZrilMHIKYcOpmO1o126Hb28FuENOcOQKlBn pP+FUX7bMe9i1FoZZbrA==; 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 1hCMko-0005BS-1S; Fri, 05 Apr 2019 11:11:26 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hCMkk-00059q-0M for linux-arm-kernel@lists.infradead.org; Fri, 05 Apr 2019 11:11:23 +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 45650168F; Fri, 5 Apr 2019 04:11:20 -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 5446E3F557; Fri, 5 Apr 2019 04:11:18 -0700 (PDT) Date: Fri, 5 Apr 2019 12:11:15 +0100 From: Dave Martin To: Andrew Jones Subject: Re: [PATCH v7 19/27] KVM: arm64: Enumerate SVE register indices for KVM_GET_REG_LIST Message-ID: <20190405111115.GX3567@e103592.cambridge.arm.com> References: <1553864452-15080-1-git-send-email-Dave.Martin@arm.com> <1553864452-15080-20-git-send-email-Dave.Martin@arm.com> <20190404140832.5ryfi35df5skg4ke@kamzik.brq.redhat.com> <20190405093545.GK3567@e103592.cambridge.arm.com> <20190405094556.6hp24jkjcrfnirsb@kamzik.brq.redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190405094556.6hp24jkjcrfnirsb@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-20190405_041122_062802_0D656820 X-CRM114-Status: GOOD ( 26.93 ) 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 11:45:56AM +0200, Andrew Jones wrote: > On Fri, Apr 05, 2019 at 10:35:45AM +0100, Dave Martin wrote: > > On Thu, Apr 04, 2019 at 04:08:32PM +0200, Andrew Jones wrote: > > > On Fri, Mar 29, 2019 at 01:00:44PM +0000, Dave Martin wrote: > > > > This patch includes the SVE register IDs in the list returned by > > > > KVM_GET_REG_LIST, as appropriate. > > > > > > > > On a non-SVE-enabled vcpu, no new IDs are added. > > > > > > > > On an SVE-enabled vcpu, IDs for the FPSIMD V-registers are removed > > > > from the list, since userspace is required to access the Z- > > > > registers instead in order to access the V-register content. For > > > > the variably-sized SVE registers, the appropriate set of slice IDs > > > > are enumerated, depending on the maximum vector length for the > > > > vcpu. > > > > > > > > As it currently stands, the SVE architecture never requires more > > > > than one slice to exist per register, so this patch adds no > > > > explicit support for enumerating multiple slices. The code can be > > > > extended straightforwardly to support this in the future, if > > > > needed. > > > > > > > > Signed-off-by: Dave Martin > > > > Reviewed-by: Julien Thierry > > > > Tested-by: zhang.lei > > > > > > > > --- [...] > > > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c [...] > > > > +static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu, > > > > + u64 __user *uindices) > > > > +{ > > > > + /* Only the first slice ever exists, for now */ [...] > > > > + const unsigned int slices = vcpu_sve_slices(vcpu); > > > > + u64 reg; > > > > + unsigned int i, n; > > > > + int num_regs = 0; > > > > + > > > > + if (!vcpu_has_sve(vcpu)) > > > > + return 0; > > > > + > > > > + for (i = 0; i < slices; i++) { > > > > + for (n = 0; n < SVE_NUM_ZREGS; n++) { > > > > + reg = KVM_REG_ARM64_SVE_ZREG(n, i); > > > > + if (put_user(reg, uindices++)) > > > > + return -EFAULT; > > > > + > > > > + num_regs++; > > > > + } > > > > + > > > > + for (n = 0; n < SVE_NUM_PREGS; n++) { > > > > + reg = KVM_REG_ARM64_SVE_PREG(n, i); > > > > + if (put_user(reg, uindices++)) > > > > + return -EFAULT; > > > > + > > > > + num_regs++; > > > > + } > > > > + > > > > + reg = KVM_REG_ARM64_SVE_FFR(i); > > > > + if (put_user(reg, uindices++)) > > > > + return -EFAULT; > > > > + > > > > + num_regs++; > > > > + } > > > > > > nit: the extra blank lines above the num_regs++'s give the code an odd > > > look (to me) > > > > There's no guaranteed fall-through onto the increments: the blank line > > was there to highlight the fact that we may jump out using a return > > instead. > > > > But I'm happy enough to change it if you have a strong preference or > > you feel the code is equally clear without. > > It's just a nit, so I don't have a strong preference :) OK, well given that you mentioned it and there are other tweaks to make on top of this patch anyway, I'll go ahead and make the change. This saves a few lines, if nothing else. Cheers ---Dave _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel