From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: buggy emulate_int_real Date: Tue, 12 Apr 2011 16:25:43 -0500 Message-ID: <20110412212543.GA906@hallyn.com> References: <20110408210900.GA26787@hallyn.com> <4DA16AA1.7010108@redhat.com> <20110412075319.GA28696@hallyn.com> <4DA406F8.4090701@redhat.com> <20110412141226.GA6766@hallyn.com> <4DA45ED0.90601@redhat.com> <4DA472E5.9060807@siemens.com> <20110412183158.GA29423@hallyn.com> <4DA4BB40.2010201@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , KVM mailing list To: Jan Kiszka Return-path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:64442 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932593Ab1DLVZu (ORCPT ); Tue, 12 Apr 2011 17:25:50 -0400 Content-Disposition: inline In-Reply-To: <4DA4BB40.2010201@web.de> Sender: kvm-owner@vger.kernel.org List-ID: Quoting Jan Kiszka (jan.kiszka@web.de): > From a brief refresh-reading, I would say > > if (interrupt.soft || kvm_exception_is_soft(nr)) > increment_eip_by_inst_len > > but only for those interrupts/exceptions which were raised by the > triggering instructions, _not_ for exceptions raise while processing > them (e.g. a page fault while accessing the IDT). > > Jan Ok, thanks guys. I'm currently trying a compile of the following. >>From a3c4d5b67eb6d91ef772bc0e04adcd7d9711275f Mon Sep 17 00:00:00 2001 From: Serge E. Hallyn Date: Tue, 12 Apr 2011 22:18:40 +0100 Subject: [PATCH 1/1] kvm: fix push of wrong eip when doing softint When doing a soft int, we need to bump eip before pushing it to the stack. Otherwise we'll do the int a second time. Signed-off-by: Serge E. Hallyn --- arch/x86/kvm/vmx.c | 12 +++++++++--- arch/x86/kvm/x86.c | 3 ++- arch/x86/kvm/x86.h | 2 +- 3 files changed, 12 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index bf89ec2..6761464 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1053,7 +1053,10 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr, } if (vmx->rmode.vm86_active) { - if (kvm_inject_realmode_interrupt(vcpu, nr) != EMULATE_DONE) + int inc_eip = 0; + if (kvm_exception_is_soft(nr)) + inc_eip = vcpu.arch.event_exit_inst_len; + if (kvm_inject_realmode_interrupt(vcpu, nr, inc_eip) != EMULATE_DONE) kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); return; } @@ -2871,7 +2874,10 @@ static void vmx_inject_irq(struct kvm_vcpu *vcpu) ++vcpu->stat.irq_injections; if (vmx->rmode.vm86_active) { - if (kvm_inject_realmode_interrupt(vcpu, irq) != EMULATE_DONE) + int inc_eip = 0; + if (vcpu->arch.interrupt.soft) + inc_eip = vcpu.arch.event_exit_inst_len; + if (kvm_inject_realmode_interrupt(vcpu, irq, inc_eip) != EMULATE_DONE) kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); return; } @@ -2905,7 +2911,7 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu) ++vcpu->stat.nmi_injections; if (vmx->rmode.vm86_active) { - if (kvm_inject_realmode_interrupt(vcpu, NMI_VECTOR) != EMULATE_DONE) + if (kvm_inject_realmode_interrupt(vcpu, NMI_VECTOR, 0) != EMULATE_DONE) kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); return; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bcc0efc..8911622 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4293,7 +4293,7 @@ static void init_emulate_ctxt(struct kvm_vcpu *vcpu) memcpy(c->regs, vcpu->arch.regs, sizeof c->regs); } -int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq) +int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip) { struct decode_cache *c = &vcpu->arch.emulate_ctxt.decode; int ret; @@ -4303,6 +4303,7 @@ int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq) vcpu->arch.emulate_ctxt.decode.op_bytes = 2; vcpu->arch.emulate_ctxt.decode.ad_bytes = 2; vcpu->arch.emulate_ctxt.decode.eip = vcpu->arch.emulate_ctxt.eip; + vcpu->arch.emulate_ctxt.decode.eip += inc_eip; ret = emulate_int_real(&vcpu->arch.emulate_ctxt, &emulate_ops, irq); if (ret != X86EMUL_CONTINUE) diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index c600da8..e407ed3 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -77,7 +77,7 @@ static inline u32 bit(int bitno) void kvm_before_handle_nmi(struct kvm_vcpu *vcpu); void kvm_after_handle_nmi(struct kvm_vcpu *vcpu); -int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq); +int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip); void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data); -- 1.7.0.4