From patchwork Sun May 24 15:50:27 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avi Kivity X-Patchwork-Id: 25609 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 n4OFq7Vt012971 for ; Sun, 24 May 2009 15:52:07 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757214AbZEXPvF (ORCPT ); Sun, 24 May 2009 11:51:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757013AbZEXPvF (ORCPT ); Sun, 24 May 2009 11:51:05 -0400 Received: from mx2.redhat.com ([66.187.237.31]:41862 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755213AbZEXPuf (ORCPT ); Sun, 24 May 2009 11:50:35 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n4OFobJs031745; Sun, 24 May 2009 11:50:37 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n4OFoaxi021109; Sun, 24 May 2009 11:50:36 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id n4OFoX5f009932; Sun, 24 May 2009 11:50:35 -0400 Received: from localhost.localdomain (cleopatra.tlv.redhat.com [10.35.255.11]) by cleopatra.tlv.redhat.com (Postfix) with ESMTP id E5D02250BC0; Sun, 24 May 2009 18:50:32 +0300 (IDT) From: Avi Kivity To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org Subject: [PATCH 42/45] KVM: inject NMI after IRET from a previous NMI, not before. Date: Sun, 24 May 2009 18:50:27 +0300 Message-Id: <1243180230-2480-43-git-send-email-avi@redhat.com> In-Reply-To: <1243180230-2480-1-git-send-email-avi@redhat.com> References: <1243180230-2480-1-git-send-email-avi@redhat.com> X-Scanned-By: MIMEDefang 2.58 on 172.16.27.26 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Gleb Natapov If NMI is received during handling of another NMI it should be injected immediately after IRET from previous NMI handler, but SVM intercept IRET before instruction execution so we can't inject pending NMI at this point and there is not way to request exit when NMI window opens. This patch fix SVM code to open NMI window after IRET by single stepping over IRET instruction. Signed-off-by: Gleb Natapov Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 2 + arch/x86/kvm/svm.c | 62 +++++++++++++++++++++++++++++++------- 2 files changed, 52 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1d6c3f7..8212943 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -358,6 +358,7 @@ struct kvm_vcpu_arch { unsigned int time_offset; struct page *time_page; + bool singlestep; /* guest is single stepped by KVM */ bool nmi_pending; bool nmi_injected; @@ -771,6 +772,7 @@ enum { #define HF_HIF_MASK (1 << 1) #define HF_VINTR_MASK (1 << 2) #define HF_NMI_MASK (1 << 3) +#define HF_IRET_MASK (1 << 4) /* * Hardware virtualization extension instructions may fault if a diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 377c4f1..71510e0 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -965,15 +965,16 @@ static void svm_set_segment(struct kvm_vcpu *vcpu, } -static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) +static void update_db_intercept(struct kvm_vcpu *vcpu) { - int old_debug = vcpu->guest_debug; struct vcpu_svm *svm = to_svm(vcpu); - vcpu->guest_debug = dbg->control; - svm->vmcb->control.intercept_exceptions &= ~((1 << DB_VECTOR) | (1 << BP_VECTOR)); + + if (vcpu->arch.singlestep) + svm->vmcb->control.intercept_exceptions |= (1 << DB_VECTOR); + if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) { if (vcpu->guest_debug & (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) @@ -984,6 +985,16 @@ static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) 1 << BP_VECTOR; } else vcpu->guest_debug = 0; +} + +static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg) +{ + int old_debug = vcpu->guest_debug; + struct vcpu_svm *svm = to_svm(vcpu); + + vcpu->guest_debug = dbg->control; + + update_db_intercept(vcpu); if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) svm->vmcb->save.dr7 = dbg->arch.debugreg[7]; @@ -1133,14 +1144,30 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) static int db_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) { if (!(svm->vcpu.guest_debug & - (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) { + (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) && + !svm->vcpu.arch.singlestep) { kvm_queue_exception(&svm->vcpu, DB_VECTOR); return 1; } - kvm_run->exit_reason = KVM_EXIT_DEBUG; - kvm_run->debug.arch.pc = svm->vmcb->save.cs.base + svm->vmcb->save.rip; - kvm_run->debug.arch.exception = DB_VECTOR; - return 0; + + if (svm->vcpu.arch.singlestep) { + svm->vcpu.arch.singlestep = false; + if (!(svm->vcpu.guest_debug & KVM_GUESTDBG_SINGLESTEP)) + svm->vmcb->save.rflags &= + ~(X86_EFLAGS_TF | X86_EFLAGS_RF); + update_db_intercept(&svm->vcpu); + } + + if (svm->vcpu.guest_debug & + (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)){ + kvm_run->exit_reason = KVM_EXIT_DEBUG; + kvm_run->debug.arch.pc = + svm->vmcb->save.cs.base + svm->vmcb->save.rip; + kvm_run->debug.arch.exception = DB_VECTOR; + return 0; + } + + return 1; } static int bp_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) @@ -1887,7 +1914,7 @@ static int iret_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) { ++svm->vcpu.stat.nmi_window_exits; svm->vmcb->control.intercept &= ~(1UL << INTERCEPT_IRET); - svm->vcpu.arch.hflags &= ~HF_NMI_MASK; + svm->vcpu.arch.hflags |= HF_IRET_MASK; return 1; } @@ -2357,8 +2384,16 @@ static void enable_nmi_window(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); - if (svm->vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) - enable_irq_window(vcpu); + if ((svm->vcpu.arch.hflags & (HF_NMI_MASK | HF_IRET_MASK)) + == HF_NMI_MASK) + return; /* IRET will cause a vm exit */ + + /* Something prevents NMI from been injected. Single step over + possible problem (IRET or exception injection or interrupt + shadow) */ + vcpu->arch.singlestep = true; + svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF); + update_db_intercept(vcpu); } static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr) @@ -2401,6 +2436,9 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) int type; u32 exitintinfo = svm->vmcb->control.exit_int_info; + if (svm->vcpu.arch.hflags & HF_IRET_MASK) + svm->vcpu.arch.hflags &= ~(HF_NMI_MASK | HF_IRET_MASK); + svm->vcpu.arch.nmi_injected = false; kvm_clear_exception_queue(&svm->vcpu); kvm_clear_interrupt_queue(&svm->vcpu);