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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 CCB59C433E0 for ; Tue, 16 Feb 2021 16:22:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A60A064DE0 for ; Tue, 16 Feb 2021 16:22:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230017AbhBPQWK (ORCPT ); Tue, 16 Feb 2021 11:22:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229764AbhBPQWB (ORCPT ); Tue, 16 Feb 2021 11:22:01 -0500 Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6300C061756 for ; Tue, 16 Feb 2021 08:21:19 -0800 (PST) Received: by mail-pg1-x52d.google.com with SMTP id 75so3157768pgf.13 for ; Tue, 16 Feb 2021 08:21:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ICaHiuq9sQswfA1xeW7s9Nu305gjOngzWGENdWHyfwo=; b=XjKpPVRuZw8GCEH6eA2RBf9/ASbC/dgnGma0Q+AKyXDZ0T6p9QUOzoUJsDe76h5lu7 ya6hUdzWAgFZJuyfPfJeidvsfxG55K7F0klJbAZnYBgfp7+I45BY2eOU6sNUjjghvdPc go1DegO0GpfqotB05aprkPvCYnCmgX0ghkLKxOfaRtPDIfZokvGAh/dtgSxBzcCNzA9f XVBFGUlYcbC330zRb1hybBZK8mG0HaM95ExkvyOJlC1jTBrI0qTj9wpLJjELa1RD8T5S FEfy1L1Q5+oAZmBgOsQi1wOw+dl8iONd0l0x2druG9Epwbz/dgo3smcQ7cUQX4O/lziz CY9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ICaHiuq9sQswfA1xeW7s9Nu305gjOngzWGENdWHyfwo=; b=hpOIqHQIO4oEROrssU2pAhhelVYgtZO3gvAtS/pDiXIhggiFnVvQWDEKwxjn0SIXG9 mmc3r6aKEq0Gkk/QXHRurDHUndOVoxUUv9KgZSIbbvy5pKKz2JkmU+IjY4x1B3NHmlu8 o6yq8Yjm/kx7vl2o5KOAmsiMNPs5pryPn7WhGBOXzJjLphIDOyf5jDtLSv8lWf3SEpQj hgjxMV/kyFoJCdyUou0Q9YpdEs6Zw0Y5Y+4IF+ipMVdEXzK54NAKOB8CgpvWRG5Ig1Oq ayLmHa3rXjvcSRqcchBQiilf0WEky3TZmEDE7YpUYiXqMiTLrwHMmwuqDRmYuUFvXKn4 CzbQ== X-Gm-Message-State: AOAM533uVaFcEaJvM2BOB0g+be1H+f9MPAkSUHtFrbhP0ZLG6P3W81y0 67s12VcQhNYmHFMnIfEqYGjuEQ== X-Google-Smtp-Source: ABdhPJwK6txOBGk6t8C7EsIVXZPKe4FVavK53stVIFcjWVnrQQ+pL5Jvv8qZcwz2xfxSjbaQ7sgNdg== X-Received: by 2002:a62:187:0:b029:1da:e323:a96b with SMTP id 129-20020a6201870000b02901dae323a96bmr20916692pfb.28.1613492479131; Tue, 16 Feb 2021 08:21:19 -0800 (PST) Received: from google.com ([2620:15c:f:10:d107:e68e:347d:fd04]) by smtp.gmail.com with ESMTPSA id j4sm20756990pfa.131.2021.02.16.08.21.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Feb 2021 08:21:18 -0800 (PST) Date: Tue, 16 Feb 2021 08:21:11 -0800 From: Sean Christopherson To: Andy Lutomirski Cc: x86@kernel.org, LKML , Sedat Dilek , Nick Desaulniers , Brian Gerst , Joerg Roedel Subject: Re: [PATCH v2 1/2] x86/stackprotector/32: Make the canary into a regular percpu variable Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 13, 2021, Andy Lutomirski wrote: > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index f923e14e87df..ec39073b4897 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -1467,12 +1467,8 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu) > #ifdef CONFIG_X86_64 > loadsegment(fs, svm->host.fs); > wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gsbase); > - load_gs_index(svm->host.gs); > -#else > -#ifdef CONFIG_X86_32_LAZY_GS > - loadsegment(gs, svm->host.gs); > -#endif This manually GS crud is gone as of commit e79b91bb3c91 ("KVM: SVM: use vmsave/vmload for saving/restoring additional host state"), which is queued for 5.12. > #endif > + load_gs_index(svm->host.gs); > > for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) > wrmsrl(host_save_user_msrs[i].index, > @@ -3705,13 +3701,11 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu, > } else { > __svm_vcpu_run(svm->vmcb_pa, (unsigned long *)&svm->vcpu.arch.regs); > > + /* Restore the percpu segment immediately. */ > #ifdef CONFIG_X86_64 > native_wrmsrl(MSR_GS_BASE, svm->host.gs_base); > #else > loadsegment(fs, svm->host.fs); > -#ifndef CONFIG_X86_32_LAZY_GS > - loadsegment(gs, svm->host.gs); > -#endif > #endif > }