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=-8.6 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,URIBL_BLOCKED,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 2DBE7C04EB8 for ; Mon, 10 Dec 2018 10:13:26 +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 F23BB20821 for ; Mon, 10 Dec 2018 10:13:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="X3Fakg+2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F23BB20821 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=i897gM25G58VrLlDDbvQ/mERMEtatml5QCJIJQ5CbkE=; b=X3Fakg+2b6tDXb 4vg9zFM41CevQcyX0B5vmFwrcoqm/6DRPiA8Y6mTMmM01EdAI9cZgpcJyNPCK2jcPr7Tm176kfZqZ nZGGm9C3GGEbDAWpv0YpXIsD/nSeUnXeQ0MulurFTqyvhhuRk4NXyQctQR5YuV4BUTatdZIAZPRR6 aSS6B0A4PpiQ1D3ISvuEmU5q16os6nZtNVQLFtey/5BjrCTCg1mVIWxuichqoGRVpVJwlGyQWUBlW vjOhP0+yHQIPvojvtbEM9Y+ppoEWXZa3P4Zj326+XNVASmRbZC7qusdwuLIaGDYtr/rm0AHu/mkhk ybBkUfpq3LRM+awS4x1A==; 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 1gWIZ1-0005Q9-6g; Mon, 10 Dec 2018 10:13:23 +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 1gWIYw-0005PD-Gb for linux-arm-kernel@lists.infradead.org; Mon, 10 Dec 2018 10:13:20 +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 8AC481596; Mon, 10 Dec 2018 02:13:07 -0800 (PST) Received: from localhost (e113682-lin.copenhagen.arm.com [10.32.144.41]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EFBCC3F6A8; Mon, 10 Dec 2018 02:13:06 -0800 (PST) Date: Mon, 10 Dec 2018 11:13:05 +0100 From: Christoffer Dall To: Marc Zyngier Subject: Re: [PATCH v3 2/8] KVM: arm64: Rework detection of SVE, !VHE systems Message-ID: <20181210101305.GH30263@e113682-lin.lund.arm.com> References: <20181206173126.139877-1-marc.zyngier@arm.com> <20181206173126.139877-3-marc.zyngier@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181206173126.139877-3-marc.zyngier@arm.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181210_021318_565643_9A10896D X-CRM114-Status: GOOD ( 23.45 ) 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: Mark Rutland , kvm@vger.kernel.org, Suzuki K Poulose , Catalin Marinas , Will Deacon , James Morse , 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 Thu, Dec 06, 2018 at 05:31:20PM +0000, Marc Zyngier wrote: > An SVE system is so far the only case where we mandate VHE. As we're > starting to grow this requirements, let's slightly rework the way we > deal with that situation, allowing for easy extension of this check. > > Signed-off-by: Marc Zyngier > --- > arch/arm/include/asm/kvm_host.h | 2 +- > arch/arm64/include/asm/kvm_host.h | 6 +++--- > virt/kvm/arm/arm.c | 8 ++++---- > 3 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 5ca5d9af0c26..2184d9ddb418 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -285,7 +285,7 @@ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot); > > struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); > > -static inline bool kvm_arch_check_sve_has_vhe(void) { return true; } > +static inline bool kvm_arch_requires_vhe(void) { return false; } > static inline void kvm_arch_hardware_unsetup(void) {} > static inline void kvm_arch_sync_events(struct kvm *kvm) {} > static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 52fbc823ff8c..d6d9aa76a943 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -422,7 +422,7 @@ static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, > } > } > > -static inline bool kvm_arch_check_sve_has_vhe(void) > +static inline bool kvm_arch_requires_vhe(void) > { > /* > * The Arm architecture specifies that implementation of SVE > @@ -430,9 +430,9 @@ static inline bool kvm_arch_check_sve_has_vhe(void) > * relies on this when SVE is present: > */ > if (system_supports_sve()) > - return has_vhe(); > - else > return true; > + > + return false; > } > > static inline void kvm_arch_hardware_unsetup(void) {} > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c > index 23774970c9df..1db4c15edcdd 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -1640,8 +1640,10 @@ int kvm_arch_init(void *opaque) > return -ENODEV; > } > > - if (!kvm_arch_check_sve_has_vhe()) { > - kvm_pr_unimpl("SVE system without VHE unsupported. Broken cpu?"); > + in_hyp_mode = is_kernel_in_hyp_mode(); > + > + if (!in_hyp_mode && kvm_arch_requires_vhe()) { > + kvm_pr_unimpl("CPU requiring VHE was booted in non-VHE mode"); nit: The error message feels weird to me (are we reporting CPU bugs?) and I'm not sure about the unimpl and I think there's a linse space missing. How about: kvm_err("Cannot support this CPU in non-VHE mode, not initializing\n"); If we wanted to be super helpful, we could expand kvm_arch_requires_vhe() with a print statement saying: kvm_err("SVE detected, requiring VHE mode\n"); But thay may be overkill. > return -ENODEV; > } > > @@ -1657,8 +1659,6 @@ int kvm_arch_init(void *opaque) > if (err) > return err; > > - in_hyp_mode = is_kernel_in_hyp_mode(); > - > if (!in_hyp_mode) { > err = init_hyp_mode(); > if (err) > -- > 2.19.2 > Otherwise: Acked-by: Christoffer Dall _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel