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=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 CF7F0C433DF for ; Mon, 29 Jun 2020 11:06:47 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 95644239EF for ; Mon, 29 Jun 2020 11:06:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sUSUSUpW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 95644239EF 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+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=merlin.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=8hmO+VSGWzabS7EwY5GIB50CnpDKlT3L/+tDO0+1kUQ=; b=sUSUSUpW7medvMwHC0ZbcPWc8 gSEoUZwk/fffczUK8jCbSagmPu3w6+D/a/rNGJMXj2dXurZyIoN44EqAg0VxNKuAbFqJt6WQaVAoA wG93NjVu4AQzoHeXjtm25X4rFc3uENhh3+V9QWtaweJkak3/otKhzYkvkJjYeQfrcQo2avnsxVl6t RX8aZ9KynKiCGSFdxbdnj4NI3ILiuz3UF34uyxVT+RO8JXNqQEJsX4015eYn3t8DxvNgD0MT5vcsj T2EWSOWmKRihFw7R+9tZHj6oAGQa5+r+t0/zPe3pOsMG1PyUHGiuHqIJrgbeDBS5zOqjWdpXaZGSn 05OziTXaA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jprbF-000319-CU; Mon, 29 Jun 2020 11:05:21 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jprbD-00030r-Bh for linux-arm-kernel@lists.infradead.org; Mon, 29 Jun 2020 11:05:20 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D37F313D5; Mon, 29 Jun 2020 04:05:17 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [10.57.20.135]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7E5C03F73C; Mon, 29 Jun 2020 04:05:16 -0700 (PDT) Date: Mon, 29 Jun 2020 12:05:13 +0100 From: Mark Rutland To: Gavin Shan Subject: Re: [PATCH 1/2] kvm/arm64: Rename HSR to ESR Message-ID: <20200629110513.GC59769@C02TD0UTHF1T.local> References: <20200629091841.88198-1-gshan@redhat.com> <20200629091841.88198-2-gshan@redhat.com> <20200629103208.GA59769@C02TD0UTHF1T.local> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200629103208.GA59769@C02TD0UTHF1T.local> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: catalin.marinas@arm.com, will@kernel.org, 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+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jun 29, 2020 at 11:32:08AM +0100, Mark Rutland wrote: > On Mon, Jun 29, 2020 at 07:18:40PM +1000, Gavin Shan wrote: > > kvm/arm32 isn't supported since commit 541ad0150ca4 ("arm: Remove > > 32bit KVM host support"). So HSR isn't meaningful since then. This > > renames HSR to ESR accordingly. This shouldn't cause any functional > > changes: > > > > * Rename kvm_vcpu_get_hsr() to kvm_vcpu_get_esr() to make the > > function names self-explanatory. > > * Rename variables from @hsr to @esr to make them self-explanatory. > > > > Signed-off-by: Gavin Shan > > At a high-level, I agree that we should move to the `esr` naming to > match the architecture and minimize surprise. However, I think there are > some ABI changes here, which *are* funcitonal changes, and those need to > be avoided. > > [...] > > > diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h > > index ba85bb23f060..d54345573a88 100644 > > --- a/arch/arm64/include/uapi/asm/kvm.h > > +++ b/arch/arm64/include/uapi/asm/kvm.h > > @@ -140,7 +140,7 @@ struct kvm_guest_debug_arch { > > }; > > > > struct kvm_debug_exit_arch { > > - __u32 hsr; > > + __u32 esr; > > __u64 far; /* used for watchpoints */ > > }; > > This is userspace ABI, and changing this *will* break userspace. This > *is* a functional change. To be slightly clearer: while the structure isn't changed, any userspace software consuming this header will fail to build after this change, beacause there will no longer be a field called `hsr`. Existing binaries will almost certianly not care, but regardless this is a regression (when building userspce) that I don't think we can permit. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel