From patchwork Wed Aug 11 12:29:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 12431137 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=-16.5 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 5C964C4320A for ; Wed, 11 Aug 2021 12:30:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 450496101E for ; Wed, 11 Aug 2021 12:30:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231371AbhHKMa6 (ORCPT ); Wed, 11 Aug 2021 08:30:58 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:55223 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232099AbhHKMa1 (ORCPT ); Wed, 11 Aug 2021 08:30:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628685003; 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=uKyYIsHDCSdQaoF2NJvHJFoI2qYTL1hOPCgjCBWaSwc=; b=Mo9ZfQyZaNP7/Wvu4Zrg4aV4ArU55PMReYCLbc4ebqJlMKHbKB8moyBTWztKC2Tq6gb71A 2SZuXAp3PJyEXgQeEvkimHnMcCdAe/HVH58qOd0pwoyfkCx/eEFgJjvDRxg6wIXlE/3fso QduaBa7GcYEjGCDLzIpe8nM4VmoRYU0= 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-90-P3mr9qJlM2uVv6scgU-DjA-1; Wed, 11 Aug 2021 08:30:01 -0400 X-MC-Unique: P3mr9qJlM2uVv6scgU-DjA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3151D801A92; Wed, 11 Aug 2021 12:29:59 +0000 (UTC) Received: from localhost.localdomain (unknown [10.35.206.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id 835725D9C6; Wed, 11 Aug 2021 12:29:50 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Kieran Bingham , Jan Kiszka , Andrew Jones , Jonathan Corbet , Maxim Levitsky , Vitaly Kuznetsov , Sean Christopherson , Ingo Molnar , Thomas Gleixner , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Johannes Berg , Wanpeng Li , "H. Peter Anvin" , Jessica Yu , Jim Mattson , Paolo Bonzini , Joerg Roedel , Yang Weijiang , linux-kernel@vger.kernel.org, Borislav Petkov , linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST FRAMEWORK), linux-doc@vger.kernel.org (open list:DOCUMENTATION), Shuah Khan , Andrew Morton Subject: [PATCH v3 3/6] KVM: SVM: implement force_intercept_exceptions_mask Date: Wed, 11 Aug 2021 15:29:24 +0300 Message-Id: <20210811122927.900604-4-mlevitsk@redhat.com> In-Reply-To: <20210811122927.900604-1-mlevitsk@redhat.com> References: <20210811122927.900604-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 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 20daaf67a5bf..72fe03506018 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1690,6 +1690,8 @@ 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 e45259177009..19f54b07161a 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -233,6 +233,8 @@ 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; @@ -1153,6 +1155,22 @@ static void svm_recalc_instruction_intercepts(struct kvm_vcpu *vcpu, } } +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); @@ -1304,6 +1322,9 @@ 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) @@ -1892,6 +1913,17 @@ 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, @@ -1967,6 +1999,40 @@ 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; @@ -3065,6 +3131,10 @@ 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 524d943f3efc..187ada7c5b03 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -196,6 +196,7 @@ struct vcpu_svm { bool ghcb_sa_free; bool guest_state_loaded; + u32 force_intercept_exceptions_mask; }; struct svm_cpu_data { @@ -351,8 +352,11 @@ 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 092e2fad3c0d..e5c7b8fa1f7f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -695,12 +695,13 @@ 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) {