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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 7C3B3C43613 for ; Fri, 21 Jun 2019 13:50:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F499206B7 for ; Fri, 21 Jun 2019 13:50:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726196AbfFUNuN (ORCPT ); Fri, 21 Jun 2019 09:50:13 -0400 Received: from foss.arm.com ([217.140.110.172]:32828 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725975AbfFUNuN (ORCPT ); Fri, 21 Jun 2019 09:50:13 -0400 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 731FA344; Fri, 21 Jun 2019 06:50:12 -0700 (PDT) Received: from [10.1.197.61] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 379FC3F575; Fri, 21 Jun 2019 06:50:11 -0700 (PDT) Subject: Re: [PATCH 06/59] KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x To: Julien Thierry , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara , Christoffer Dall , Dave Martin , Jintack Lim , James Morse , Suzuki K Poulose References: <20190621093843.220980-1-marc.zyngier@arm.com> <20190621093843.220980-7-marc.zyngier@arm.com> <7f8a9d76-6087-b8d9-3571-074a08d08ec8@arm.com> From: Marc Zyngier Openpgp: preference=signencrypt Autocrypt: addr=marc.zyngier@arm.com; prefer-encrypt=mutual; keydata= mQINBE6Jf0UBEADLCxpix34Ch3kQKA9SNlVQroj9aHAEzzl0+V8jrvT9a9GkK+FjBOIQz4KE g+3p+lqgJH4NfwPm9H5I5e3wa+Scz9wAqWLTT772Rqb6hf6kx0kKd0P2jGv79qXSmwru28vJ t9NNsmIhEYwS5eTfCbsZZDCnR31J6qxozsDHpCGLHlYym/VbC199Uq/pN5gH+5JHZyhyZiNW ozUCjMqC4eNW42nYVKZQfbj/k4W9xFfudFaFEhAf/Vb1r6F05eBP1uopuzNkAN7vqS8XcgQH qXI357YC4ToCbmqLue4HK9+2mtf7MTdHZYGZ939OfTlOGuxFW+bhtPQzsHiW7eNe0ew0+LaL 3wdNzT5abPBscqXWVGsZWCAzBmrZato+Pd2bSCDPLInZV0j+rjt7MWiSxEAEowue3IcZA++7 ifTDIscQdpeKT8hcL+9eHLgoSDH62SlubO/y8bB1hV8JjLW/jQpLnae0oz25h39ij4ijcp8N t5slf5DNRi1NLz5+iaaLg4gaM3ywVK2VEKdBTg+JTg3dfrb3DH7ctTQquyKun9IVY8AsxMc6 lxl4HxrpLX7HgF10685GG5fFla7R1RUnW5svgQhz6YVU33yJjk5lIIrrxKI/wLlhn066mtu1 DoD9TEAjwOmpa6ofV6rHeBPehUwMZEsLqlKfLsl0PpsJwov8TQARAQABtCNNYXJjIFp5bmdp ZXIgPG1hcmMuenluZ2llckBhcm0uY29tPokCTwQTAQIAOQIbAwYLCQgHAwIGFQgCCQoLBBYC AwECHgECF4AWIQSf1RxT4LVjGP2VnD0j0NC60T16QwUCXO+WxgAKCRAj0NC60T16QzfuEACd oPsSJdUg3nm61VKq86Pp0mfCC5IVyD/vTDw3jDErsmtT7t8mMVgidSJe9cMEudLO5xske/mY sC7ZZ4GFNRRsFs3wY5g+kg4yk2UY6q18HXRQJwzWCug2bkJPUxbh71nS3KPsvq4BBOeQiTIX Xr0lTyReFAp+JZ0HpanAU/iD2usEZLDNLXYLRjaHlfkwouxt02XcTKbqRWNtKl3Ybj+mz5IA qEQnA5Z8Nt9ZQmlZ4ASiXVVCbZKIR3RewBL6BP4OhYrvcPCtkoqlqKWZoHBs3ZicRXvcVUr/ nqUyZpqhmfht2mIE063L3kTfBqxJ1SQqPc0ZIModTh4ATEjC44x8ObQvtnmgL8EKJBhxJfjY EUYLnwSejH1h+qgj94vn7n1RMVqXpCrWHyF7pCDBqq3gBxtDu6TWgi4iwh4CtdOzXBw2V39D LlnABnrZl5SdVbRwV+Ek1399s/laceH8e4uNea50ho89WmP9AUCrXlawHohfDE3GMOV4BdQ2 DbJAtZnENQXaRK9gr86jbGQBga9VDvsBbRd+uegEmQ8nPspryWIz/gDRZLXIG8KE9Jj9OhwE oiusVTLsw7KS4xKDK2Ixb/XGtJPLtUXbMM1n9YfLsB5JPZ3B08hhrv+8Vmm734yCXtxI0+7B F1V4T2njuJKWTsmJWmx+tIY8y9muUK9rabkCDQROiX9FARAAz/al0tgJaZ/eu0iI/xaPk3DK NIvr9SsKFe2hf3CVjxriHcRfoTfriycglUwtvKvhvB2Y8pQuWfLtP9Hx3H+YI5a78PO2tU1C JdY5Momd3/aJBuUFP5blbx6n+dLDepQhyQrAp2mVC3NIp4T48n4YxL4Og0MORytWNSeygISv Rordw7qDmEsa7wgFsLUIlhKmmV5VVv+wAOdYXdJ9S8n+XgrxSTgHj5f3QqkDtT0yG8NMLLmY kZpOwWoMumeqn/KppPY/uTIwbYTD56q1UirDDB5kDRL626qm63nF00ByyPY+6BXH22XD8smj f2eHw2szECG/lpD4knYjxROIctdC+gLRhz+Nlf8lEHmvjHgiErfgy/lOIf+AV9lvDF3bztjW M5oP2WGeR7VJfkxcXt4JPdyDIH6GBK7jbD7bFiXf6vMiFCrFeFo/bfa39veKUk7TRlnX13go gIZxqR6IvpkG0PxOu2RGJ7Aje/SjytQFa2NwNGCDe1bH89wm9mfDW3BuZF1o2+y+eVqkPZj0 mzfChEsiNIAY6KPDMVdInILYdTUAC5H26jj9CR4itBUcjE/tMll0n2wYRZ14Y/PM+UosfAhf YfN9t2096M9JebksnTbqp20keDMEBvc3KBkboEfoQLU08NDo7ncReitdLW2xICCnlkNIUQGS WlFVPcTQ2sMAEQEAAYkCHwQYAQIACQUCTol/RQIbDAAKCRAj0NC60T16QwsFD/9T4y30O0Wn MwIgcU8T2c2WwKbvmPbaU2LDqZebHdxQDemX65EZCv/NALmKdA22MVSbAaQeqsDD5KYbmCyC czilJ1i+tpZoJY5kJALHWWloI6Uyi2s1zAwlMktAZzgGMnI55Ifn0dAOK0p8oy7/KNGHNPwJ eHKzpHSRgysQ3S1t7VwU4mTFJtXQaBFMMXg8rItP5GdygrFB7yUbG6TnrXhpGkFBrQs9p+SK vCqRS3Gw+dquQ9QR+QGWciEBHwuSad5gu7QC9taN8kJQfup+nJL8VGtAKgGr1AgRx/a/V/QA ikDbt/0oIS/kxlIdcYJ01xuMrDXf1jFhmGZdocUoNJkgLb1iFAl5daV8MQOrqciG+6tnLeZK HY4xCBoigV7E8KwEE5yUfxBS0yRreNb+pjKtX6pSr1Z/dIo+td/sHfEHffaMUIRNvJlBeqaj BX7ZveskVFafmErkH7HC+7ErIaqoM4aOh/Z0qXbMEjFsWA5yVXvCoJWSHFImL9Bo6PbMGpI0 9eBrkNa1fd6RGcktrX6KNfGZ2POECmKGLTyDC8/kb180YpDJERN48S0QBa3Rvt06ozNgFgZF Wvu5Li5PpY/t/M7AAkLiVTtlhZnJWyEJrQi9O2nXTzlG1PeqGH2ahuRxn7txA5j5PHZEZdL1 Z46HaNmN2hZS/oJ69c1DI5Rcww== Organization: ARM Ltd Message-ID: <3a68e4e6-878f-7272-4e2d-8768680287fd@arm.com> Date: Fri, 21 Jun 2019 14:50:08 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <7f8a9d76-6087-b8d9-3571-074a08d08ec8@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 21/06/2019 14:24, Julien Thierry wrote: > > > On 21/06/2019 10:37, Marc Zyngier wrote: >> From: Christoffer Dall >> >> We were not allowing userspace to set a more privileged mode for the VCPU >> than EL1, but we should allow this when nested virtualization is enabled >> for the VCPU. >> >> Signed-off-by: Christoffer Dall >> Signed-off-by: Marc Zyngier >> --- >> arch/arm64/kvm/guest.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c >> index 3ae2f82fca46..4c35b5d51e21 100644 >> --- a/arch/arm64/kvm/guest.c >> +++ b/arch/arm64/kvm/guest.c >> @@ -37,6 +37,7 @@ >> #include >> #include >> #include >> +#include >> #include >> >> #include "trace.h" >> @@ -194,6 +195,11 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) >> if (vcpu_el1_is_32bit(vcpu)) >> return -EINVAL; >> break; >> + case PSR_MODE_EL2h: >> + case PSR_MODE_EL2t: >> + if (vcpu_el1_is_32bit(vcpu) || !nested_virt_in_use(vcpu)) > > This condition reads a bit weirdly. Why do we care about anything else > than !nested_virt_in_use() ? > > If nested virt is not in use then obviously we return the error. > > If nested virt is in use then why do we care about EL1? Or should this > test read as "highest_el_is_32bit" ? There are multiple things at play here: - MODE_EL2x is not a valid 32bit mode - The architecture forbids nested virt with 32bit EL2 The code above is a simplification of these two conditions. But certainly we can do a bit better, as kvm_reset_cpu() doesn't really check that we don't create a vcpu with both 32bit+NV. These two bits should really be exclusive. M. -- Jazz is not dead. It just smells funny...