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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 47D95C433ED for ; Thu, 1 Apr 2021 10:52:25 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 925F261056 for ; Thu, 1 Apr 2021 10:52:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 925F261056 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 2ADC24B5CB; Thu, 1 Apr 2021 06:52:24 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id q62sZ1zAPpHL; Thu, 1 Apr 2021 06:52:22 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id ED3E64B647; Thu, 1 Apr 2021 06:52:22 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id E857B4B60C for ; Thu, 1 Apr 2021 06:52:21 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 4qDJZv42gKbw for ; Thu, 1 Apr 2021 06:52:21 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id CD9F34B5CB for ; Thu, 1 Apr 2021 06:52:20 -0400 (EDT) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E19DC61005; Thu, 1 Apr 2021 10:52:18 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lRuvw-0055Zn-Dw; Thu, 01 Apr 2021 11:52:16 +0100 Date: Thu, 01 Apr 2021 11:52:15 +0100 Message-ID: <87wntmp99c.wl-maz@kernel.org> From: Marc Zyngier To: Eric Auger Subject: Re: [PATCH v4 1/8] KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base In-Reply-To: <20210401085238.477270-2-eric.auger@redhat.com> References: <20210401085238.477270-1-eric.auger@redhat.com> <20210401085238.477270-2-eric.auger@redhat.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: eric.auger@redhat.com, eric.auger.pro@gmail.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, drjones@redhat.com, alexandru.elisei@arm.com, james.morse@arm.com, suzuki.poulose@arm.com, shuah@kernel.org, pbonzini@redhat.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: kvm@vger.kernel.org, shuah@kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, kvmarm@lists.cs.columbia.edu, eric.auger.pro@gmail.com X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Hi Eric, On Thu, 01 Apr 2021 09:52:31 +0100, Eric Auger wrote: > > KVM_DEV_ARM_VGIC_GRP_ADDR group doc says we should return > -EEXIST in case the base address of the redist is already set. > We currently return -EINVAL. > > However we need to return -EINVAL in case a legacy REDIST address > is attempted to be set while REDIST_REGIONS were set. This case > is discriminated by looking at the count field. > > Signed-off-by: Eric Auger > > --- > > v1 -> v2: > - simplify the check sequence > --- > arch/arm64/kvm/vgic/vgic-mmio-v3.c | 15 +++++++-------- > 1 file changed, 7 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c > index 15a6c98ee92f0..013b737b658f8 100644 > --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c > +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c > @@ -791,10 +791,6 @@ static int vgic_v3_insert_redist_region(struct kvm *kvm, uint32_t index, > size_t size = count * KVM_VGIC_V3_REDIST_SIZE; > int ret; > > - /* single rdist region already set ?*/ > - if (!count && !list_empty(rd_regions)) > - return -EINVAL; > - > /* cross the end of memory ? */ > if (base + size < base) > return -EINVAL; > @@ -805,11 +801,14 @@ static int vgic_v3_insert_redist_region(struct kvm *kvm, uint32_t index, > } else { > rdreg = list_last_entry(rd_regions, > struct vgic_redist_region, list); > - if (index != rdreg->index + 1) > - return -EINVAL; > > - /* Cannot add an explicitly sized regions after legacy region */ > - if (!rdreg->count) > + if ((!count) != (!rdreg->count)) > + return -EINVAL; /* Mix REDIST and REDIST_REGION */ Urgh... The triple negation killed me. Can we come up with a more intuitive expression? Something like: /* Don't mix single region and discrete redist regions */ if (!count && rdreg->count) return -EINVAL; Does it capture what you want to express? Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm