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 8A288C433EF for ; Fri, 15 Jul 2022 20:42:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230152AbiGOUmh (ORCPT ); Fri, 15 Jul 2022 16:42:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229680AbiGOUmf (ORCPT ); Fri, 15 Jul 2022 16:42:35 -0400 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE4F5528A6 for ; Fri, 15 Jul 2022 13:42:34 -0700 (PDT) Received: by mail-pl1-x64a.google.com with SMTP id b13-20020a170902e94d00b001692fd82122so2587601pll.14 for ; Fri, 15 Jul 2022 13:42:34 -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=I/QtSIUAt/ll33VekTJLh62H8IcuJ8z6tut6BxZsMlM=; b=fyGq4PDW6nNQF4AgVR2GWsJutzb8REI7X30M+jAdJvMXKIiLqLV5+41RoSH2TGMyke In+cj7mPYK0r2awY7X/evjcY1kdNfY5xPXJX6mKoMWvW0p4NbdxM4tS3pqpygfvoilha niWGT/MtkjgADD6uIh8CZcOLymPLPPYO+HH5SnFUYjuDVL7HF3fRUMp600ZRo64UzB3e jYHhdk8F3/6eRvz9JbkcvSpg3wg1t3jEsVc/NV7alHZUvcf59/mzzwHxk8lHlKbElHUG XrjEh9gsJNP8BGFl6FJs6w8e1tPTPfWlWQ29EuF9fElc/jZ3mhk9iZVa8yPXnhaWavgs YCLg== 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=I/QtSIUAt/ll33VekTJLh62H8IcuJ8z6tut6BxZsMlM=; b=wQK0AbYrOHvhqhHXCIjqMs62mBAFo+18Nqp2zgO9EylnMjfd8tBDKaj4eyIKr5hCEt zKqYp5TOShrxrlw9gupRsaVydNlwe2Wg1zMPAUu6FJbwFOe/v6DW1jwytb0aNM0uaR6t 17Y47PL97hnaAnB/g0+pTQTmKp7/OlRDfNTcsOzo+MMAu2wY1AmHL406w6AqqQzqj18D RoRo0Iemk9CjdU02XTcyV5bzPVZKtT3xQWAF+yjqK7Zx9TrbS8mDz4PhWs9eQm2Ks3BW dDsp/XpFbsyVFZb/k4ck/hlO1K/AAwjTO7LDj4XWMVduIKYSlt5Qj6b358OYybWcnFnN yKCA== X-Gm-Message-State: AJIora8a95I/Kj3tDK4dvtx3wTe5B5Gat2xg3HS9m3J+45kJrhAYcYcB vGEePyIrk3hpDVUHjGCh26mZ4iNhJ0w= X-Google-Smtp-Source: AGRyM1sFgmYzLtmfKLJLV5nfuc4k+8wI40y5q4ho5M0nFm/EHMVCPOr80cRtiKWNrD4WZI42WiPdfLuL+9Y= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90a:f8ce:b0:1ef:798c:ae03 with SMTP id l14-20020a17090af8ce00b001ef798cae03mr24290306pjd.8.1657917754552; Fri, 15 Jul 2022 13:42:34 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 15 Jul 2022 20:42:02 +0000 Message-Id: <20220715204226.3655170-1-seanjc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.37.0.170.g444d1eabd0-goog Subject: [PATCH v2 00/24] KVM: x86: Event/exception fixes and cleanups From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Jim Mattson , Maxim Levitsky , Oliver Upton , Peter Shier Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The main goal of this series is to fix KVM's longstanding bug of not honoring L1's exception intercepts wants when handling an exception that occurs during delivery of a different exception. E.g. if L0 and L1 are using shadow paging, and L2 hits a #PF, and then hits another #PF while vectoring the first #PF due to _L1_ not having a shadow page for the IDT, KVM needs to check L1's intercepts before morphing the #PF => #PF => #DF so that the #PF is routed to L1, not injected into L2 as a #DF. nVMX has hacked around the bug for years by overriding the #PF injector for shadow paging to go straight to VM-Exit, and nSVM has started doing the same. The hacks mostly work, but they're incomplete, confusing, and lead to other hacky code, e.g. bailing from the emulator because #PF injection forced a VM-Exit and suddenly KVM is back in L1. Maxim, I believe I addressed all of your comments, holler if I missed something. v2: - Collect reviews. [Maxim, Jim] - Split a few patches into more consumable chunks. [Maxim] - Document that KVM doesn't correctly handle SMI+MTF (or SMI priority). [Maxim] - Add comment to document the instruction boundary (event window) aspect of block_nested_events. [Maxim] - Add a patch to rename inject_pending_events() and add a comment to document KVM's not-quite-architecturally-correct handing of instruction boundaries and asynchronous events. [Maxim] v1: https://lore.kernel.org/all/20220614204730.3359543-1-seanjc@google.com Sean Christopherson (24): KVM: nVMX: Unconditionally purge queued/injected events on nested "exit" KVM: VMX: Drop bits 31:16 when shoving exception error code into VMCS KVM: x86: Don't check for code breakpoints when emulating on exception KVM: nVMX: Treat General Detect #DB (DR7.GD=1) as fault-like KVM: nVMX: Prioritize TSS T-flag #DBs over Monitor Trap Flag KVM: x86: Treat #DBs from the emulator as fault-like (code and DR7.GD=1) KVM: x86: Use DR7_GD macro instead of open coding check in emulator KVM: nVMX: Ignore SIPI that arrives in L2 when vCPU is not in WFS KVM: nVMX: Unconditionally clear mtf_pending on nested VM-Exit KVM: VMX: Inject #PF on ENCLS as "emulated" #PF KVM: x86: Rename kvm_x86_ops.queue_exception to inject_exception KVM: x86: Make kvm_queued_exception a properly named, visible struct KVM: x86: Formalize blocking of nested pending exceptions KVM: x86: Use kvm_queue_exception_e() to queue #DF KVM: x86: Hoist nested event checks above event injection logic KVM: x86: Evaluate ability to inject SMI/NMI/IRQ after potential VM-Exit KVM: nVMX: Add a helper to identify low-priority #DB traps KVM: nVMX: Document priority of all known events on Intel CPUs KVM: x86: Morph pending exceptions to pending VM-Exits at queue time KVM: x86: Treat pending TRIPLE_FAULT requests as pending exceptions KVM: VMX: Update MTF and ICEBP comments to document KVM's subtle behavior KVM: x86: Rename inject_pending_events() to kvm_check_and_inject_events() KVM: selftests: Use uapi header to get VMX and SVM exit reasons/codes KVM: selftests: Add an x86-only test to verify nested exception queueing arch/x86/include/asm/kvm-x86-ops.h | 2 +- arch/x86/include/asm/kvm_host.h | 35 +- arch/x86/kvm/emulate.c | 3 +- arch/x86/kvm/svm/nested.c | 110 ++--- arch/x86/kvm/svm/svm.c | 20 +- arch/x86/kvm/vmx/nested.c | 329 ++++++++----- arch/x86/kvm/vmx/sgx.c | 2 +- arch/x86/kvm/vmx/vmx.c | 53 ++- arch/x86/kvm/x86.c | 450 ++++++++++++------ arch/x86/kvm/x86.h | 11 +- tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/include/x86_64/svm_util.h | 7 +- .../selftests/kvm/include/x86_64/vmx.h | 51 +- .../kvm/x86_64/nested_exceptions_test.c | 295 ++++++++++++ 15 files changed, 950 insertions(+), 420 deletions(-) create mode 100644 tools/testing/selftests/kvm/x86_64/nested_exceptions_test.c base-commit: 8031d87aa9953ddeb047a5356ebd0b240c30f233 -- 2.37.0.170.g444d1eabd0-goog