From patchwork Thu Nov 12 12:21:24 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gleb Natapov X-Patchwork-Id: 59575 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id nACCLcD1013335 for ; Thu, 12 Nov 2009 12:21:38 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751425AbZKLMV2 (ORCPT ); Thu, 12 Nov 2009 07:21:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751336AbZKLMV2 (ORCPT ); Thu, 12 Nov 2009 07:21:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53779 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751173AbZKLMV1 (ORCPT ); Thu, 12 Nov 2009 07:21:27 -0500 Received: from int-mx05.intmail.prod.int.phx2.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.18]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id nACCLTYj017157 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 12 Nov 2009 07:21:29 -0500 Received: from dhcp-1-237.tlv.redhat.com (dhcp-1-237.tlv.redhat.com [10.35.1.237]) by int-mx05.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id nACCLQZh008261; Thu, 12 Nov 2009 07:21:27 -0500 Received: by dhcp-1-237.tlv.redhat.com (Postfix, from userid 13519) id EA8991336CD; Thu, 12 Nov 2009 14:21:24 +0200 (IST) Date: Thu, 12 Nov 2009 14:21:24 +0200 From: Gleb Natapov To: Marcelo Tosatti Cc: kvm@vger.kernel.org, jan.kiszka@siemens.com, joerg.roedel@amd.com Subject: Re: [patch 0/2] Handle multiple exceptions (fixes Win2003 reboot by triple fault) Message-ID: <20091112122124.GB7392@redhat.com> References: <20091111192947.348198723@localhost.localdomain> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20091111192947.348198723@localhost.localdomain> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.18 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 76c8375..88c4490 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -248,12 +248,61 @@ void kvm_set_apic_base(struct kvm_vcpu *vcpu, u64 data) } EXPORT_SYMBOL_GPL(kvm_set_apic_base); +#define EXCPT_BENIGN 0 +#define EXCPT_CONTRIBUTORY 1 +#define EXCPT_PF 2 + +static int exception_class(int vector) +{ + if (vector == 14) + return EXCPT_PF; + else if (vector == 0 || (vector >= 10 && vector <= 13)) + return EXCPT_CONTRIBUTORY; + else + return EXCPT_BENIGN; +} + +static void kvm_multiple_exception(struct kvm_vcpu *vcpu, + unsigned nr, bool has_error, u32 error_code) +{ + u32 prev_nr; + int class1, class2; + + if (!vcpu->arch.exception.pending) { + queue: + vcpu->arch.exception.pending = true; + vcpu->arch.exception.has_error_code = has_error; + vcpu->arch.exception.nr = nr; + vcpu->arch.exception.error_code = error_code; + return; + } + + /* to check exception */ + prev_nr = vcpu->arch.exception.nr; + if (prev_nr == DF_VECTOR) { + /* triple fault -> shutdown */ + set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests); + return; + } + class1 = exception_class(prev_nr); + class2 = exception_class(nr); + if ((class1 == EXCPT_CONTRIBUTORY && class2 == EXCPT_CONTRIBUTORY) + || (class1 == EXCPT_PF && class2 != EXCPT_BENIGN)) { + /* generate double fault per SDM Table 5-5 */ + vcpu->arch.exception.pending = true; + vcpu->arch.exception.has_error_code = true; + vcpu->arch.exception.nr = DF_VECTOR; + vcpu->arch.exception.error_code = 0; + } else + /* replace previous exception with a new one in a hope + that instruction re-execution will regenerate lost + exception */ + goto queue; +} + void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr) { - WARN_ON(vcpu->arch.exception.pending); - vcpu->arch.exception.pending = true; - vcpu->arch.exception.has_error_code = false; - vcpu->arch.exception.nr = nr; + kvm_multiple_exception(vcpu, nr, false, 0); } EXPORT_SYMBOL_GPL(kvm_queue_exception); @@ -261,25 +310,6 @@ void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long addr, u32 error_code) { ++vcpu->stat.pf_guest; - - if (vcpu->arch.exception.pending) { - switch(vcpu->arch.exception.nr) { - case DF_VECTOR: - /* triple fault -> shutdown */ - set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests); - return; - case PF_VECTOR: - vcpu->arch.exception.nr = DF_VECTOR; - vcpu->arch.exception.error_code = 0; - return; - default: - /* replace previous exception with a new one in a hope - that instruction re-execution will regenerate lost - exception */ - vcpu->arch.exception.pending = false; - break; - } - } vcpu->arch.cr2 = addr; kvm_queue_exception_e(vcpu, PF_VECTOR, error_code); } @@ -292,11 +322,7 @@ EXPORT_SYMBOL_GPL(kvm_inject_nmi); void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code) { - WARN_ON(vcpu->arch.exception.pending); - vcpu->arch.exception.pending = true; - vcpu->arch.exception.has_error_code = true; - vcpu->arch.exception.nr = nr; - vcpu->arch.exception.error_code = error_code; + kvm_multiple_exception(vcpu, nr, true, error_code); } EXPORT_SYMBOL_GPL(kvm_queue_exception_e);