From patchwork Thu Apr 29 11:58:47 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gleb Natapov X-Patchwork-Id: 95921 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 o3UHKnhF010707 for ; Fri, 30 Apr 2010 17:20:53 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933059Ab0D3RSu (ORCPT ); Fri, 30 Apr 2010 13:18:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51973 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933013Ab0D3RSo (ORCPT ); Fri, 30 Apr 2010 13:18:44 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o3TBwncu028281 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 29 Apr 2010 07:58:49 -0400 Received: from dhcp-1-237.tlv.redhat.com (dhcp-1-237.tlv.redhat.com [10.35.1.237]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o3TBwmjA024532; Thu, 29 Apr 2010 07:58:48 -0400 Received: by dhcp-1-237.tlv.redhat.com (Postfix, from userid 13519) id A9F6C1336CF; Thu, 29 Apr 2010 14:58:47 +0300 (IDT) Date: Thu, 29 Apr 2010 14:58:47 +0300 From: Gleb Natapov To: avi@redhat.com, mtosatti@redhat.com Cc: kvm@vger.kernel.org Subject: [PATCH RFC] KVM: inject #UD if instruction emulation fails while vcpu is in cpl==3 Message-ID: <20100429115847.GW10044@redhat.com> MIME-Version: 1.0 Content-Disposition: inline X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 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]); Fri, 30 Apr 2010 17:20:53 +0000 (UTC) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index ed48904..5aa0944 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -575,7 +575,6 @@ enum emulation_result { #define EMULTYPE_SKIP (1 << 2) int emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, u16 error_code, int emulation_type); -void kvm_report_emulation_failure(struct kvm_vcpu *cvpu, const char *context); void realmode_lgdt(struct kvm_vcpu *vcpu, u16 size, unsigned long address); void realmode_lidt(struct kvm_vcpu *vcpu, u16 size, unsigned long address); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index ddfa865..4ddcb1b 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2776,11 +2776,8 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code) return 1; case EMULATE_DO_MMIO: ++vcpu->stat.mmio_exits; - return 0; + /* fall through */ case EMULATE_FAIL: - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; return 0; default: BUG(); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 889f660..b2eed27 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1449,7 +1449,7 @@ static int io_interception(struct vcpu_svm *svm) string = (io_info & SVM_IOIO_STR_MASK) != 0; in = (io_info & SVM_IOIO_TYPE_MASK) != 0; if (string || in) - return !(emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO); + return emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DONE; port = io_info >> 16; size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT; @@ -2297,16 +2297,12 @@ static int iret_interception(struct vcpu_svm *svm) static int invlpg_interception(struct vcpu_svm *svm) { - if (emulate_instruction(&svm->vcpu, 0, 0, 0) != EMULATE_DONE) - pr_unimpl(&svm->vcpu, "%s: failed\n", __func__); - return 1; + return emulate_instruction(&svm->vcpu, 0, 0, 0) == EMULATE_DONE; } static int emulate_on_interception(struct vcpu_svm *svm) { - if (emulate_instruction(&svm->vcpu, 0, 0, 0) != EMULATE_DONE) - pr_unimpl(&svm->vcpu, "%s: failed\n", __func__); - return 1; + return emulate_instruction(&svm->vcpu, 0, 0, 0) == EMULATE_DONE; } static int cr8_write_interception(struct vcpu_svm *svm) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 875b785..d05bc46 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3003,7 +3003,7 @@ static int handle_io(struct kvm_vcpu *vcpu) ++vcpu->stat.io_exits; if (string || in) - return !(emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DO_MMIO); + return emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DONE; port = exit_qualification >> 16; size = (exit_qualification & 7) + 1; @@ -3260,22 +3260,7 @@ static int handle_wbinvd(struct kvm_vcpu *vcpu) static int handle_apic_access(struct kvm_vcpu *vcpu) { - unsigned long exit_qualification; - enum emulation_result er; - unsigned long offset; - - exit_qualification = vmcs_readl(EXIT_QUALIFICATION); - offset = exit_qualification & 0xffful; - - er = emulate_instruction(vcpu, 0, 0, 0); - - if (er != EMULATE_DONE) { - printk(KERN_ERR - "Fail to handle apic access vmexit! Offset is 0x%lx\n", - offset); - return -ENOEXEC; - } - return 1; + return emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DONE; } static int handle_task_switch(struct kvm_vcpu *vcpu) @@ -3487,13 +3472,8 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) goto out; } - if (err != EMULATE_DONE) { - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; - ret = 0; - goto out; - } + if (err != EMULATE_DONE) + return 0; if (signal_pending(current)) goto out; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 299b602..9be8b84 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3577,24 +3577,6 @@ int emulator_set_dr(int dr, unsigned long value, struct kvm_vcpu *vcpu) return __kvm_set_dr(vcpu, dr, value); } -void kvm_report_emulation_failure(struct kvm_vcpu *vcpu, const char *context) -{ - u8 opcodes[4]; - unsigned long rip = kvm_rip_read(vcpu); - unsigned long rip_linear; - - if (!printk_ratelimit()) - return; - - rip_linear = rip + get_segment_base(vcpu, VCPU_SREG_CS); - - kvm_read_guest_virt(rip_linear, (void *)opcodes, 4, vcpu, NULL); - - printk(KERN_ERR "emulation failed (%s) rip %lx %02x %02x %02x %02x\n", - context, rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]); -} -EXPORT_SYMBOL_GPL(kvm_report_emulation_failure); - static u64 mk_cr_64(u64 curr_cr, u32 new_val) { return (curr_cr & ~((1ULL << 32) - 1)) | new_val; @@ -3801,6 +3783,27 @@ static void inject_emulated_exception(struct kvm_vcpu *vcpu) kvm_queue_exception(vcpu, ctxt->exception); } +static int handle_emulation_failure(struct kvm_vcpu *vcpu) +{ + struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt; + + ++vcpu->stat.insn_emulation_fail; + trace_kvm_emulate_insn_failed(vcpu); + if (ctxt->cpl != 3) { + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; + vcpu->run->internal.ndata = 0; + return EMULATE_FAIL; + } else { + /* + * if emulation failed in userspace inject #UD + * instead of killing VM + */ + kvm_queue_exception(vcpu, UD_VECTOR); + return EMULATE_DONE; + } +} + int emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, u16 error_code, @@ -3869,11 +3872,11 @@ int emulate_instruction(struct kvm_vcpu *vcpu, ++vcpu->stat.insn_emulation; if (r) { - ++vcpu->stat.insn_emulation_fail; - trace_kvm_emulate_insn_failed(vcpu); if (kvm_mmu_unprotect_page_virt(vcpu, cr2)) return EMULATE_DONE; - return EMULATE_FAIL; + if (emulation_type & EMULTYPE_SKIP) + return EMULATE_FAIL; + return handle_emulation_failure(vcpu); } } @@ -3898,9 +3901,7 @@ restart: if (kvm_mmu_unprotect_page_virt(vcpu, cr2)) return EMULATE_DONE; - trace_kvm_emulate_insn_failed(vcpu); - kvm_report_emulation_failure(vcpu, "mmio"); - return EMULATE_FAIL; + return handle_emulation_failure(vcpu); } toggle_interruptibility(vcpu, vcpu->arch.emulate_ctxt.interruptibility); @@ -4734,7 +4735,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); r = emulate_instruction(vcpu, 0, 0, EMULTYPE_NO_DECODE); srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); - if (r == EMULATE_DO_MMIO) { + if (r != EMULATE_DONE) { r = 0; goto out; }