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=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 61AB8C43461 for ; Thu, 1 Apr 2021 18:32:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 382F460FDA for ; Thu, 1 Apr 2021 18:32:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236749AbhDASch (ORCPT ); Thu, 1 Apr 2021 14:32:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:42742 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238815AbhDASKM (ORCPT ); Thu, 1 Apr 2021 14:10:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617300611; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cc3k8MO13oibHy+9e3XEGxkpJb9ZoYiN6eARau7Wqk8=; b=hvFDMM8ADLPRBWUVVE1dWk9MDHiOZVMe/ruPLYDia/S22msT57XSGrESVaf94VnSNlXWwK trFX5B84CxEikEFtpxuh8Z0C/MgdKE6h2xZLP46nmZipkT5071v+txLdqBpwgNMBSx0Wyc sLADgfNLSsEAa3iSiTtUG6YS/YJEGOQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-529-7sofkHCGOwurHwhGCrWEYQ-1; Thu, 01 Apr 2021 07:43:52 -0400 X-MC-Unique: 7sofkHCGOwurHwhGCrWEYQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 93E7B801814; Thu, 1 Apr 2021 11:43:50 +0000 (UTC) Received: from [10.36.112.13] (ovpn-112-13.ams2.redhat.com [10.36.112.13]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E04B716917; Thu, 1 Apr 2021 11:43:47 +0000 (UTC) Subject: Re: [PATCH v4 1/8] KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base To: Marc Zyngier Cc: 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 References: <20210401085238.477270-1-eric.auger@redhat.com> <20210401085238.477270-2-eric.auger@redhat.com> <87wntmp99c.wl-maz@kernel.org> From: Auger Eric Message-ID: <419be8ac-6fbb-a712-a398-311ca68d52f9@redhat.com> Date: Thu, 1 Apr 2021 13:43:46 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <87wntmp99c.wl-maz@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marc, On 4/1/21 12:52 PM, Marc Zyngier wrote: > 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: Yes sometimes I can be "different" ;-) > > /* Don't mix single region and discrete redist regions */ > if (!count && rdreg->count) > return -EINVAL;> > Does it capture what you want to express? yes it does! Thanks Eric > > Thanks, > > M. >