From patchwork Sat Jul 23 00:51:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 12926996 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 46926C43334 for ; Sat, 23 Jul 2022 00:51:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235202AbiGWAvp (ORCPT ); Fri, 22 Jul 2022 20:51:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230215AbiGWAvo (ORCPT ); Fri, 22 Jul 2022 20:51:44 -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 41907101F3 for ; Fri, 22 Jul 2022 17:51:43 -0700 (PDT) Received: by mail-pl1-x64a.google.com with SMTP id d10-20020a170902ceca00b0016bea2dc145so3410557plg.7 for ; Fri, 22 Jul 2022 17:51:43 -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=ys0GEGydU2uam+ngTo0juEJ4Yk0g/q5LIx8twKFbkvo=; b=eoJyzr4WnjHgJiPyv/j3LYAggu5KZ6mgGOSC+8DjGmkVg0ZQkSGqMkngQAsl8GQHTr Qh63sE0ukJVkRBYSl1oDORksOiGHnIi5eQENeRmJinEEuLjBaEI6r9dEA/EKh7Yc1H+K xhWMHn0IWuzmRzpqZycznbL9BKA5rUA6vdplBVkslg0hQg4V3FAd1Wv9vxSstOCwGA3i Cj1F1sHHFfRW5gvCdjiVCBA9Cn9SbjZX83685VAfn5cl1C6akRPsXB89IaxNM3wm5KZd g2IOqE4EblmvV+cFSC62c5SEdZDVsDLWRhwaQlAcpdtZxqfXm9b/efZ1I07zg85s3Yy2 b53Q== 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=ys0GEGydU2uam+ngTo0juEJ4Yk0g/q5LIx8twKFbkvo=; b=POvj3CH7A/8yz00/N4KfWpVyqPUEONcP1ir05+PmgV/H/hQJ2z5/+Dqs9GgqwoKdeM 7rBf5RtLF+CgDB/IZIjy2iUnKNW+gWuynZYSqdCEBCjQtwmpMHSMBBDEAh0jjp80EwFt 6vST+iXSVMczFzNxrspra+l6SYGM+Ny2oQGsKbgHfo5CJwEYmiKvhDrYZmhVtz3qjRFH 9pbx7zxak6cd/HREjKGd7UQMq7ykOUaytNXIlDnvy7rXms3R2BBp1QcHYkkZQ958n/gk 5a/LE/teIajbZ8AF37FWneM9C47P//rZ9VJ7+ncPENnVFm3BHSIOYl45BSWhn3UdAh9/ +yaw== X-Gm-Message-State: AJIora+UsmBAshFpTgrIuocCoURutjnj5oT3SD9qQAEkBdLjLpbrexkV fEFuC6V6IhpKU0hcHwUrXLG3uw8IAQ4= X-Google-Smtp-Source: AGRyM1sNSto+k2nljue71DnqV97d9qArsGrPWIPo3Wa8vvX1skLmXUMNbkt7w98ictKfa8YZGCclE5ggSYg= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90a:249:b0:1e0:a8a3:3c6c with SMTP id t9-20020a17090a024900b001e0a8a33c6cmr1127906pje.0.1658537502542; Fri, 22 Jul 2022 17:51:42 -0700 (PDT) Reply-To: Sean Christopherson Date: Sat, 23 Jul 2022 00:51:13 +0000 Message-Id: <20220723005137.1649592-1-seanjc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.37.1.359.gd136c6c3e2-goog Subject: [PATCH v4 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 Precedence: bulk List-ID: X-Mailing-List: kvm@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. v4: - Collect reviews. [Maxim] - Fix a bug where an intermediate patch dropped the async #PF token and used a stale payload. [Maxim] - Tweak comments to call out that AMD CPUs generate error codes with bits 31:16 != 0. [Maxim] v3: - https://lore.kernel.org/all/20220715204226.3655170-1-seanjc@google.com - 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] v2: - https://lore.kernel.org/all/20220614204730.3359543-1-seanjc@google.com - Rebased to kvm/queue (commit 8baacf67c76c) + selftests CPUID overhaul. https://lore.kernel.org/all/20220614200707.3315957-1-seanjc@google.com - Treat KVM_REQ_TRIPLE_FAULT as a pending exception. 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 | 331 ++++++++----- arch/x86/kvm/vmx/sgx.c | 2 +- arch/x86/kvm/vmx/vmx.c | 54 ++- 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, 953 insertions(+), 420 deletions(-) create mode 100644 tools/testing/selftests/kvm/x86_64/nested_exceptions_test.c base-commit: 1a4d88a361af4f2e91861d632c6a1fe87a9665c2