From patchwork Thu Apr 1 13:54:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 12178875 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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 4150EC43461 for ; Thu, 1 Apr 2021 18:02:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F20F61001 for ; Thu, 1 Apr 2021 18:02:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236264AbhDASCZ (ORCPT ); Thu, 1 Apr 2021 14:02:25 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20483 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234866AbhDAR6T (ORCPT ); Thu, 1 Apr 2021 13:58:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617299896; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IeSCqCBagWzFXJCY1w7HB1qDOO9KpHIs4Tyewq8aOvs=; b=bfDDatFi6U62JtAXbut2417zAPLhEld8fUfnXiiUDfijvOZSBc1SfbACLk9u7yRo2TtpTu lGz6W+j4UkwyzuBTS0fvCq67z1+R+4ICBH/Q7DY8RLJ2RSCLGIxltKaQMjZGc6Y6lgV21q dvuD2Av8YUO0/kvzkB/6VD6/UnTNe74= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-221-tafvrKJ1O3-YC537vN-qRQ-1; Thu, 01 Apr 2021 09:57:12 -0400 X-MC-Unique: tafvrKJ1O3-YC537vN-qRQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 807611853020; Thu, 1 Apr 2021 13:57:08 +0000 (UTC) Received: from localhost.localdomain (unknown [10.35.206.58]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8A617627DD; Thu, 1 Apr 2021 13:56:27 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Ingo Molnar , Andrew Morton , Thomas Gleixner , Sean Christopherson , Marc Zyngier , Catalin Marinas , linux-kernel@vger.kernel.org (open list), Julien Thierry , Stefano Garzarella , Borislav Petkov , Suzuki K Poulose , Jonathan Corbet , Jessica Yu , "H. Peter Anvin" , Jan Kiszka , Will Deacon , kvmarm@lists.cs.columbia.edu (open list:KERNEL VIRTUAL MACHINE FOR ARM64 (KVM/arm64)), Paolo Bonzini , Vitaly Kuznetsov , Vasily Gorbik , Joerg Roedel , Claudio Imbrenda , Jim Mattson , Cornelia Huck , David Hildenbrand , Maxim Levitsky , Wanpeng Li , Janosch Frank , Christian Borntraeger , linux-s390@vger.kernel.org (open list:S390), Heiko Carstens , Kieran Bingham , linux-doc@vger.kernel.org (open list:DOCUMENTATION), linux-arm-kernel@lists.infradead.org (moderated list:KERNEL VIRTUAL MACHINE FOR ARM64 (KVM/arm64)), James Morse Subject: [PATCH v2 9/9] KVM: SVM: implement force_intercept_exceptions_mask Date: Thu, 1 Apr 2021 16:54:51 +0300 Message-Id: <20210401135451.1004564-10-mlevitsk@redhat.com> In-Reply-To: <20210401135451.1004564-1-mlevitsk@redhat.com> References: <20210401135451.1004564-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Currently #TS interception is only done once. Also exception interception is not enabled for SEV guests. Signed-off-by: Maxim Levitsky --- arch/x86/include/asm/kvm_host.h | 2 + arch/x86/kvm/svm/svm.c | 70 +++++++++++++++++++++++++++++++++ arch/x86/kvm/svm/svm.h | 6 ++- arch/x86/kvm/x86.c | 5 ++- 4 files changed, 80 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 8c529ae9dbbe..d15ae64a2c4e 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1574,6 +1574,8 @@ int kvm_emulate_rdpmc(struct kvm_vcpu *vcpu); void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr); void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code); void kvm_queue_exception_p(struct kvm_vcpu *vcpu, unsigned nr, unsigned long payload); +void kvm_queue_exception_e_p(struct kvm_vcpu *vcpu, unsigned nr, + u32 error_code, unsigned long payload); void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr); void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code); void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 2aa951bc470c..de7fd7922ec7 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -220,6 +220,8 @@ static const u32 msrpm_ranges[] = {0, 0xc0000000, 0xc0010000}; #define MSRS_RANGE_SIZE 2048 #define MSRS_IN_RANGE (MSRS_RANGE_SIZE * 8 / 2) +static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code); + u32 svm_msrpm_offset(u32 msr) { u32 offset; @@ -1113,6 +1115,22 @@ static void svm_check_invpcid(struct vcpu_svm *svm) } } +static void svm_init_force_exceptions_intercepts(struct vcpu_svm *svm) +{ + int exc; + + svm->force_intercept_exceptions_mask = force_intercept_exceptions_mask; + for (exc = 0 ; exc < 32 ; exc++) { + if (!(svm->force_intercept_exceptions_mask & (1 << exc))) + continue; + + /* Those are defined to have undefined behavior in the SVM spec */ + if (exc != 2 && exc != 9) + continue; + set_exception_intercept(svm, exc); + } +} + static void init_vmcb(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -1288,6 +1306,9 @@ static void init_vmcb(struct kvm_vcpu *vcpu) enable_gif(svm); + if (!sev_es_guest(vcpu->kvm)) + svm_init_force_exceptions_intercepts(svm); + } static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) @@ -1913,6 +1934,17 @@ static int pf_interception(struct kvm_vcpu *vcpu) u64 fault_address = svm->vmcb->control.exit_info_2; u64 error_code = svm->vmcb->control.exit_info_1; + if ((svm->force_intercept_exceptions_mask & (1 << PF_VECTOR))) + if (npt_enabled && !vcpu->arch.apf.host_apf_flags) { + /* If the #PF was only intercepted for debug, inject + * it directly to the guest, since the kvm's mmu code + * is not ready to deal with such page faults. + */ + kvm_queue_exception_e_p(vcpu, PF_VECTOR, + error_code, fault_address); + return 1; + } + return kvm_handle_page_fault(vcpu, error_code, fault_address, static_cpu_has(X86_FEATURE_DECODEASSISTS) ? svm->vmcb->control.insn_bytes : NULL, @@ -1988,6 +2020,40 @@ static int ac_interception(struct kvm_vcpu *vcpu) return 1; } +static int gen_exc_interception(struct kvm_vcpu *vcpu) +{ + /* + * Generic exception intercept handler which forwards a guest exception + * as-is to the guest. + * For exceptions that don't have a special intercept handler. + * + * Used only for 'force_intercept_exceptions_mask' KVM debug feature. + */ + struct vcpu_svm *svm = to_svm(vcpu); + int exc = svm->vmcb->control.exit_code - SVM_EXIT_EXCP_BASE; + + /* SVM doesn't provide us with an error code for the #DF */ + u32 err_code = exc == DF_VECTOR ? 0 : svm->vmcb->control.exit_info_1; + + if (!(svm->force_intercept_exceptions_mask & (1 << exc))) + return svm_handle_invalid_exit(vcpu, svm->vmcb->control.exit_code); + + if (exc == TS_VECTOR) { + /* + * SVM doesn't provide us with an error code to be able to + * re-inject the #TS exception, so just disable its + * intercept, and let the guest re-execute the instruction. + */ + vmcb_clr_intercept(&svm->vmcb01.ptr->control, + INTERCEPT_EXCEPTION_OFFSET + TS_VECTOR); + recalc_intercepts(svm); + } else if (x86_exception_has_error_code(exc)) + kvm_queue_exception_e(vcpu, exc, err_code); + else + kvm_queue_exception(vcpu, exc); + return 1; +} + static bool is_erratum_383(void) { int err, i; @@ -3051,6 +3117,10 @@ static int (*const svm_exit_handlers[])(struct kvm_vcpu *vcpu) = { [SVM_EXIT_WRITE_DR5] = dr_interception, [SVM_EXIT_WRITE_DR6] = dr_interception, [SVM_EXIT_WRITE_DR7] = dr_interception, + + [SVM_EXIT_EXCP_BASE ... + SVM_EXIT_EXCP_BASE + 31] = gen_exc_interception, + [SVM_EXIT_EXCP_BASE + DB_VECTOR] = db_interception, [SVM_EXIT_EXCP_BASE + BP_VECTOR] = bp_interception, [SVM_EXIT_EXCP_BASE + UD_VECTOR] = ud_interception, diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 8e276c4fb33d..79d0aea87753 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -183,6 +183,7 @@ struct vcpu_svm { bool ghcb_sa_free; bool guest_state_loaded; + u32 force_intercept_exceptions_mask; }; struct svm_cpu_data { @@ -333,8 +334,11 @@ static inline void clr_exception_intercept(struct vcpu_svm *svm, u32 bit) struct vmcb *vmcb = svm->vmcb01.ptr; WARN_ON_ONCE(bit >= 32); - vmcb_clr_intercept(&vmcb->control, INTERCEPT_EXCEPTION_OFFSET + bit); + if ((1 << bit) & svm->force_intercept_exceptions_mask) + return; + + vmcb_clr_intercept(&vmcb->control, INTERCEPT_EXCEPTION_OFFSET + bit); recalc_intercepts(svm); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1a51031d64d8..ae57816fe6d9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -630,12 +630,13 @@ void kvm_queue_exception_p(struct kvm_vcpu *vcpu, unsigned nr, } EXPORT_SYMBOL_GPL(kvm_queue_exception_p); -static void kvm_queue_exception_e_p(struct kvm_vcpu *vcpu, unsigned nr, - u32 error_code, unsigned long payload) +void kvm_queue_exception_e_p(struct kvm_vcpu *vcpu, unsigned nr, + u32 error_code, unsigned long payload) { kvm_multiple_exception(vcpu, nr, true, error_code, true, payload, false); } +EXPORT_SYMBOL_GPL(kvm_queue_exception_e_p); int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err) {