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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93E1BC433FE for ; Fri, 15 Apr 2022 00:43:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348111AbiDOAqQ (ORCPT ); Thu, 14 Apr 2022 20:46:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245477AbiDOAqO (ORCPT ); Thu, 14 Apr 2022 20:46:14 -0400 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A21296832 for ; Thu, 14 Apr 2022 17:43:47 -0700 (PDT) Received: by mail-pj1-x104a.google.com with SMTP id z88-20020a17090a6d6100b001cb89a1969fso3642282pjj.1 for ; Thu, 14 Apr 2022 17:43:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:message-id:mime-version:subject:from:to:cc; bh=7OMi2RIEzFlzmxnmlN9xX+Hiuvy0euETloS8ByI5IaE=; b=MeCa2hpH2EDOFAv86dWfFxEDhUCoVgtYtspWsZspfLv8qId3NORSe7rf03wn86oylz +XJ0GcdqQRybf6xncuTBeePmfFN4InpFQ41P9BSR3Syo01zZHvGZ9zQr4T4EE1WEIloe reG4s0K2VYD7FLIjoouyOUE3otCfnre0GNbLyJfTBPWb2DV4bee0Kn/uLaXDFLxrNX/x UbZV6ELm90R1ITrDKiVMDDPojI8aJ036Iusf7S6xFX02aeLgG7OCHcrKOwsYwLbInWX3 PegPDslVaW429FO+Y+K2OsH/9FIvKxrhlxBKuaQed7QGbk7x/m+I+YhWAP5nEspT3bi9 F2eA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:message-id:mime-version:subject :from:to:cc; bh=7OMi2RIEzFlzmxnmlN9xX+Hiuvy0euETloS8ByI5IaE=; b=KH2AFudW1IwrjFZqoPYdiwZPCQ+lm3W8qbUXU/K0Ku5L8HsAdbc8xUdv83pu6ltTlv M/vvIk7Y+DcP6wxQxJ3pYfYXnuZOC4ZBI15FmdAxWu149i1Fruoqh9K//7z9fRRescRz UhMoCWL2bqtxoEecRmP0A6H1U4y3yhC0EjHI3wIGdS4SqQlAocRCT6Albqry+GPAVKrJ o3f3KQjrvsoyMGQoAe7K2LwI9wSqYXC0iitrREBcAO7T1fy11eh5nWmscmnJgYP9oy7J gVJiYAjrMaajP98jhQMv8Q06pLmG2PI+9DmXyD/8AuGiOJJYpaRGBRaSNTgLr0rDlBOG tNVQ== X-Gm-Message-State: AOAM533vA6GOWEjSel8nSPqNvS8G2eXhpl3s5togZFukD7axk1qCFgsb BLQdo4USep2IoPgnf6JZkR1gH787dOI= X-Google-Smtp-Source: ABdhPJx6JOuyqIVZMdQQ1Mawo8G7YZO4giLYHAwOTFBDw/d0CTLHvznAoZ7hbCtCNcCnHHDws4949mgI1FE= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a05:6a00:1490:b0:4fb:1544:bc60 with SMTP id v16-20020a056a00149000b004fb1544bc60mr17317476pfu.73.1649983426720; Thu, 14 Apr 2022 17:43:46 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 15 Apr 2022 00:43:40 +0000 Message-Id: <20220415004343.2203171-1-seanjc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.36.0.rc0.470.gd361397f0d-goog Subject: [PATCH 0/3] KVM: x86 SRCU bug fix and SRCU hardening From: Sean Christopherson To: Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Paolo Bonzini Cc: Atish Patra , David Hildenbrand , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix an x86 bug where KVM overwrites vcpu->srcu_idx and can leak an SRCU lock due to unlocking the wrong index, ultimately causing a hang if/when KVM attempts to synchronize. Switch RISC-V to the generic vcpu->srcu_idx, for reasons unknown it has its own copy and ignores the generic one. Add helpers with rudimentary detection of illegal vcpu->srcu_idx usage, the x86 bug would have been incredibly painful to debug had I not known what to look for (found by a selftest with very specific behavior... that we recently modified with respect to SRCU). Non-x86 changes are compile tested only. Sean Christopherson (3): KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io() KVM: RISC-V: Use kvm_vcpu.srcu_idx, drop RISC-V's unnecessary copy KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abused arch/powerpc/kvm/book3s_64_mmu_radix.c | 9 ++++--- arch/powerpc/kvm/book3s_hv_nested.c | 16 ++++++------ arch/powerpc/kvm/book3s_rtas.c | 4 +-- arch/powerpc/kvm/powerpc.c | 4 +-- arch/riscv/include/asm/kvm_host.h | 3 --- arch/riscv/kvm/vcpu.c | 16 ++++++------ arch/riscv/kvm/vcpu_exit.c | 4 +-- arch/s390/kvm/interrupt.c | 4 +-- arch/s390/kvm/kvm-s390.c | 8 +++--- arch/s390/kvm/vsie.c | 4 +-- arch/x86/kvm/x86.c | 35 +++++++++++--------------- include/linux/kvm_host.h | 24 +++++++++++++++++- 12 files changed, 72 insertions(+), 59 deletions(-) base-commit: 150866cd0ec871c765181d145aa0912628289c8a -- 2.36.0.rc0.470.gd361397f0d-goog