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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 729B6C2D0A3 for ; Mon, 26 Oct 2020 13:55:15 +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 19A1B2463C for ; Mon, 26 Oct 2020 13:55:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="uJsZnrT2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 19A1B2463C Authentication-Results: mail.kernel.org; dmarc=fail (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=pyJB1/6UAMmYLHvf/TKa5zjHdJdDVBl4mINV2lAW8B0=; b=uJsZnrT22EiVUPySNfM4oWbP9 U0h88bLKlEMkJSjYEax6ELVP5VrDtLGX9iNl7AuWiyQJVW/jLhaVooi0YrE8aeP/qqI0ilWB6Leyb u/UqiI6ZtIxNqFWnnA5Go5oy8u9lN1ZfJy1VjdS3hFbUVBP7rC86OvXrsWLPlXSTFqWOfGVsvpduH q1Xn7+CKRcfvrVMcUe3N6qzlgq0c3IrH5Wxgu3dIe6UkRu492dbTxHtG1domxUHlpcR5Sods4bSRb HJTGpQR5DD968QsjO/Gz5bjUJzdXG+fIGZ80MrLKjliKnv/YQ9fmhIfcW4gLWBNuPxjwp25FaTdPA 8lHdolbJw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kX2wN-0007tS-Pi; Mon, 26 Oct 2020 13:53:40 +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 1kX2vx-0007mS-Ov for linux-arm-kernel@lists.infradead.org; Mon, 26 Oct 2020 13:53:17 +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 9DB49106F; Mon, 26 Oct 2020 06:53:12 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [10.57.56.187]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1557A3F68F; Mon, 26 Oct 2020 06:53:10 -0700 (PDT) Date: Mon, 26 Oct 2020 13:53:08 +0000 From: Mark Rutland To: Marc Zyngier Subject: Re: [PATCH 01/11] KVM: arm64: Don't adjust PC on SError during SMC trap Message-ID: <20201026135308.GC12454@C02TD0UTHF1T.local> References: <20201026133450.73304-1-maz@kernel.org> <20201026133450.73304-2-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201026133450.73304-2-maz@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201026_095314_842377_027F7725 X-CRM114-Status: GOOD ( 24.91 ) 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: Will Deacon , kernel-team@android.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.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, Oct 26, 2020 at 01:34:40PM +0000, Marc Zyngier wrote: > On SMC trap, the prefered return address is set to that of the SMC > instruction itself. It is thus wrong to tyr and roll it back when Typo: s/tyr/try/ > an SError occurs while trapping on SMC. It is still necessary on > HVC though, as HVC doesn't cause a trap, and sets ELR to returning > *after* the HVC. > > It also became apparent that the is 16bit encoding for an AArch32 I guess s/that the is/that there is no/ ? > HVC instruction, meaning that the displacement is always 4 bytes, > no matter what the ISA is. Take this opportunity to simplify it. > > Signed-off-by: Marc Zyngier Assuming that there is no 16-bit HVC: Acked-by: Mark Rutland Mark. > --- > arch/arm64/kvm/handle_exit.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c > index 5d690d60ccad..79a720657c47 100644 > --- a/arch/arm64/kvm/handle_exit.c > +++ b/arch/arm64/kvm/handle_exit.c > @@ -245,15 +245,15 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index) > u8 esr_ec = ESR_ELx_EC(kvm_vcpu_get_esr(vcpu)); > > /* > - * HVC/SMC already have an adjusted PC, which we need > - * to correct in order to return to after having > - * injected the SError. > + * HVC already have an adjusted PC, which we need to > + * correct in order to return to after having injected > + * the SError. > + * > + * SMC, on the other hand, is *trapped*, meaning its > + * preferred return address is the SMC itself. > */ > - if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64 || > - esr_ec == ESR_ELx_EC_SMC32 || esr_ec == ESR_ELx_EC_SMC64) { > - u32 adj = kvm_vcpu_trap_il_is32bit(vcpu) ? 4 : 2; > - *vcpu_pc(vcpu) -= adj; > - } > + if (esr_ec == ESR_ELx_EC_HVC32 || esr_ec == ESR_ELx_EC_HVC64) > + *vcpu_pc(vcpu) -= 4; > > return 1; > } > -- > 2.28.0 > > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel