From nobody Mon Feb 9 08:29:04 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2139C32793 for ; Wed, 18 Jan 2023 14:54:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230305AbjAROyn (ORCPT ); Wed, 18 Jan 2023 09:54:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230350AbjAROyD (ORCPT ); Wed, 18 Jan 2023 09:54:03 -0500 Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E9CC17CEE for ; Wed, 18 Jan 2023 06:48:53 -0800 (PST) Received: by mail-ed1-x534.google.com with SMTP id v10so48720914edi.8 for ; Wed, 18 Jan 2023 06:48:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=grsecurity.net; s=grsec; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=b6W0pZJ6ERcXnvSOd8zNWpB3EIqXZWM69qX+jHbVTMc=; b=IBT0qj/RPtCvkxVkBIfHYd7QteXzIP67i647IqhTBlkd71McZh+opt3wap1cZCAih3 qyu/DTKBwBL6nJT2BGjW5K+gPq+wjvxNqGY4YPXwZLTySKFOF+VSovv5xJ7QsXwxK3y8 Q4c1c+jL2v1+8AQPHNvhgpgZInBCLehbKZ/7FKuYASFL00ghpeud/Qriwg/I3m+4SBAg AM57y1MJKZI7tIx14X5KraP3NJ0/u8reJ3vBvZhwAfMvVJ8PPRnegZh9Na9R6sWEuY0Y TiIys37zs94rkWlC81Vy9Hk1Sl/tH8OJSvrxfjuhAjZ2t0PaqTX3Ke3cW1I7Uw0NweEg E4Rw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=b6W0pZJ6ERcXnvSOd8zNWpB3EIqXZWM69qX+jHbVTMc=; b=YLv3tJJQY2N3DfTDYrqQXUu6qeqAoz4LnLc8J0m6ESjH+sKGJ6YIF+RjpslFD2DYiG zBf6+MYHmaiTd1aQDV4tzc43PvrNtSWCNytJAO8FhJ5pBikK/Ep2KH2qTu037TxG84wD RLSW2xFWZQtABYSfbWJgQbwB6gqkbpVO0teSqB7xFH7Q/+6UFxUFV0sLR1vzcu73aaVi LwqA76DnoiX7xBUVKxgEIDAfF7B/goOTdDt4fOu8ZaKSGUAbVqaVLoigoov5lnjQRt7E TdrgboGg2gbuzBWNtHWsk0T5drVn2/j64gqynLKWgzGrfF2o+31Ovvzi4KaFzleCn8Ht I2/A== X-Gm-Message-State: AFqh2krGFqPocLidVNjBZIpCP2HyyaPy/MT8nrfSOSQe8dpMn0bshIH/ VT7/TttGOEioys6c31rtAiNYqw== X-Google-Smtp-Source: AMrXdXtppojCwB78sS5kdfJaEsCFQeirzrmEFUA3pTLC71BZn/8fPScn2OIOm+zqjicgcf0NIlV1yw== X-Received: by 2002:aa7:cb01:0:b0:495:fa3d:1d72 with SMTP id s1-20020aa7cb01000000b00495fa3d1d72mr7477248edt.8.1674053332042; Wed, 18 Jan 2023 06:48:52 -0800 (PST) Received: from nuc.fritz.box (p200300f6af03d2006e0fc0b921f9db5c.dip0.t-ipconnect.de. [2003:f6:af03:d200:6e0f:c0b9:21f9:db5c]) by smtp.gmail.com with ESMTPSA id p11-20020a05640243cb00b0049e19136c22sm3627509edc.95.2023.01.18.06.48.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Jan 2023 06:48:51 -0800 (PST) From: Mathias Krause To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Sean Christopherson , Paolo Bonzini , Mathias Krause Subject: [PATCH v2 2/3] KVM: VMX: avoid retpoline call for control register caused exits Date: Wed, 18 Jan 2023 15:50:29 +0100 Message-Id: <20230118145030.40845-3-minipli@grsecurity.net> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230118145030.40845-1-minipli@grsecurity.net> References: <20230118145030.40845-1-minipli@grsecurity.net> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Complement commit 4289d2728664 ("KVM: retpolines: x86: eliminate retpoline from vmx.c exit handlers") and avoid a retpoline call for control register accesses as well. This speeds up guests that make heavy use of it, like grsecurity kernels toggling CR0.WP to implement kernel W^X. Signed-off-by: Mathias Krause --- SVM may gain from a similar change as well, however, I've no AMD box to test this on. arch/x86/kvm/vmx/vmx.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index c788aa382611..c8198c8a9b55 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6538,6 +6538,8 @@ static int __vmx_handle_exit(struct kvm_vcpu *vcpu, f= astpath_t exit_fastpath) return handle_external_interrupt(vcpu); else if (exit_reason.basic =3D=3D EXIT_REASON_HLT) return kvm_emulate_halt(vcpu); + else if (exit_reason.basic =3D=3D EXIT_REASON_CR_ACCESS) + return handle_cr(vcpu); else if (exit_reason.basic =3D=3D EXIT_REASON_EPT_MISCONFIG) return handle_ept_misconfig(vcpu); #endif --=20 2.39.0