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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 02984C197A0 for ; Fri, 17 Nov 2023 00:57:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=WJWy4LZK1PrHZ1DXeUtfar+ipoM4rqTEvY8xwXQPb2Y=; b=3q8vTB22r4ytkk x5jJQk5exv6MsE+YRzvVA0XePcnZLflGvHTZu2I3/byMuEorVQsLu/7NPVOYhPRm54Pu3j8ck/BIk D5L/9hnGSg4Ve/31OWICPiwgX0Q//3pKtwYXoaCJne9flNwc8or9xT/Q2zxqc/Xxb4Qp/upOcIW0k Vt3zOCs+bPRbxj4pyNddvBXNobwacWCyvAKm8hwb8zqkyzb4CVRerLzcsqGcPAsPTC2Zr1/QBVtMz V0H6v4XUUNvY4B9ERWd86DLmA0s1nkxmaesbdO3Svpxw0Yk+n+pA7KXlMPjz6GGDv8kdqVaB+CQG5 hi3Z7oyoLrKcYKnhBOAQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r3nAK-005MqJ-0h; Fri, 17 Nov 2023 00:57:00 +0000 Received: from out-179.mta1.migadu.com ([2001:41d0:203:375::b3]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r3nAH-005MpX-12 for linux-arm-kernel@lists.infradead.org; Fri, 17 Nov 2023 00:56:59 +0000 Date: Thu, 16 Nov 2023 16:56:36 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1700182611; 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: in-reply-to:in-reply-to:references:references; bh=0fkuxnbdYW25Ttqk3TZq2xjlT9j7u45ZxdRPegBk1nc=; b=B3CttyUlvMewr2QCXhIT1Q9CjzccwGX43KO4LIQ5urb6rWu0syJZ1cWZbDUB2DU58FLxRW fb1am80CHDLINuxDIfQoZ8bcM7sgIPgCYKAWMe113cqWMSJ6wZ8IDbzEVIrN5dQJaD0thQ WPoYiHr8WwQ/Hp0ijLE6bFxzhNGxV14= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, Catalin Marinas , Will Deacon , Mark Rutland , James Morse , Suzuki K Poulose , Zenghui Yu Subject: Re: [PATCH 05/12] arm64: cpufeature: Detect E2H0 not being implemented Message-ID: References: <20231113174244.3026520-1-maz@kernel.org> <20231113174244.3026520-6-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20231113174244.3026520-6-maz@kernel.org> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231116_165657_762903_8821D2E4 X-CRM114-Status: GOOD ( 16.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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, Nov 13, 2023 at 05:42:37PM +0000, Marc Zyngier wrote: > FEAT_E2H0 is a new feature that indicates whether or not HCR_EL2.E2H > can be set to 0. Amusingly, this feature is set to 0 when implemented, > and otherwise negative. > > Add a new capability and detection infrastructure to detect the > absence of FEAT_E2H0. > > Signed-off-by: Marc Zyngier Reviewed-by: Oliver Upton > --- > arch/arm64/kernel/cpufeature.c | 7 +++++++ > arch/arm64/tools/cpucaps | 1 + > 2 files changed, 8 insertions(+) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 41db7f993eef..e0d64e8b4851 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -2787,6 +2787,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { > .matches = has_cpuid_feature, > ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, EVT, IMP) > }, > + { > + .desc = "FEAT_E2H0 not implemented", > + .capability = ARM64_HCR_E2H_RES1, I did read this a couple times before the neurons that interpret "0 not implemented" and "RES1" fired together, heh. -- Thanks, Oliver _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel