From patchwork Tue Feb 23 16:47:56 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 81487 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o1NGmMvO015915 for ; Tue, 23 Feb 2010 16:48:23 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753462Ab0BWQsV (ORCPT ); Tue, 23 Feb 2010 11:48:21 -0500 Received: from david.siemens.de ([192.35.17.14]:19632 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753400Ab0BWQsT (ORCPT ); Tue, 23 Feb 2010 11:48:19 -0500 Received: from mail1.siemens.de (localhost [127.0.0.1]) by david.siemens.de (8.12.11.20060308/8.12.11) with ESMTP id o1NGm1Vn008448; Tue, 23 Feb 2010 17:48:01 +0100 Received: from localhost.localdomain (mchn012c.mchp.siemens.de [139.25.109.167] (may be forged)) by mail1.siemens.de (8.12.11.20060308/8.12.11) with ESMTP id o1NGm0PX003583; Tue, 23 Feb 2010 17:48:01 +0100 From: Jan Kiszka To: Avi Kivity , Marcelo Tosatti Cc: kvm , Gleb Natapov Subject: [PATCH v2 4/7] KVM: SVM: Emulate nRIP feature when reinjecting INT3 Date: Tue, 23 Feb 2010 17:47:56 +0100 Message-Id: <901d87e18613376f5d0bb0f4f73856b306253dba.1266943665.git.jan.kiszka@siemens.com> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: References: In-Reply-To: References: Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Tue, 23 Feb 2010 16:48:23 +0000 (UTC) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 2fceac8..d11ff46 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -46,6 +46,7 @@ MODULE_LICENSE("GPL"); #define SVM_FEATURE_NPT (1 << 0) #define SVM_FEATURE_LBRV (1 << 1) #define SVM_FEATURE_SVML (1 << 2) +#define SVM_FEATURE_NRIP (1 << 3) #define SVM_FEATURE_PAUSE_FILTER (1 << 10) #define NESTED_EXIT_HOST 0 /* Exit handled on host level */ @@ -109,6 +110,9 @@ struct vcpu_svm { struct nested_state nested; bool nmi_singlestep; + + unsigned int3_injected; + unsigned long int3_rip; }; /* enable NPT for AMD64 and X86 with PAE */ @@ -290,6 +294,22 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr, if (nested_svm_check_exception(svm, nr, has_error_code, error_code)) return; + if (nr == BP_VECTOR && !svm_has(SVM_FEATURE_NRIP)) { + unsigned long rip, old_rip = kvm_rip_read(&svm->vcpu); + + /* + * For guest debugging where we have to reinject #BP if some + * INT3 is guest-owned: + * Emulate nRIP by moving RIP forward. Will fail if injection + * raises a fault that is not intercepted. Still better than + * failing in all cases. + */ + skip_emulated_instruction(&svm->vcpu); + rip = kvm_rip_read(&svm->vcpu); + svm->int3_rip = rip + svm->vmcb->save.cs.base; + svm->int3_injected = rip - old_rip; + } + svm->vmcb->control.event_inj = nr | SVM_EVTINJ_VALID | (has_error_code ? SVM_EVTINJ_VALID_ERR : 0) @@ -2695,6 +2715,9 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) u8 vector; int type; u32 exitintinfo = svm->vmcb->control.exit_int_info; + unsigned int3_injected = svm->int3_injected; + + svm->int3_injected = 0; if (svm->vcpu.arch.hflags & HF_IRET_MASK) svm->vcpu.arch.hflags &= ~(HF_NMI_MASK | HF_IRET_MASK); @@ -2714,12 +2737,21 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) svm->vcpu.arch.nmi_injected = true; break; case SVM_EXITINTINFO_TYPE_EXEPT: - /* In case of software exception do not reinject an exception - vector, but re-execute and instruction instead */ if (is_nested(svm)) break; - if (kvm_exception_is_soft(vector)) + /* + * In case of software exceptions, do not reinject the vector, + * but re-execute the instruction instead. Rewind RIP first + * if we emulated INT3 before. + */ + if (kvm_exception_is_soft(vector)) { + if (vector == BP_VECTOR && int3_injected && + kvm_is_linear_rip(&svm->vcpu, svm->int3_rip)) + kvm_rip_write(&svm->vcpu, + kvm_rip_read(&svm->vcpu) - + int3_injected); break; + } if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) { u32 err = svm->vmcb->control.exit_int_info_err; kvm_queue_exception_e(&svm->vcpu, vector, err);