From patchwork Thu Jan 27 08:30:51 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nadav Har'El X-Patchwork-Id: 510471 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p0R8Uwq8011166 for ; Thu, 27 Jan 2011 08:30:58 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751999Ab1A0Iaz (ORCPT ); Thu, 27 Jan 2011 03:30:55 -0500 Received: from mtagate4.uk.ibm.com ([194.196.100.164]:54615 "EHLO mtagate4.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751956Ab1A0Iaz (ORCPT ); Thu, 27 Jan 2011 03:30:55 -0500 Received: from d06nrmr1806.portsmouth.uk.ibm.com (d06nrmr1806.portsmouth.uk.ibm.com [9.149.39.193]) by mtagate4.uk.ibm.com (8.13.1/8.13.1) with ESMTP id p0R8UsLW004473 for ; Thu, 27 Jan 2011 08:30:54 GMT Received: from d06av07.portsmouth.uk.ibm.com (d06av07.portsmouth.uk.ibm.com [9.149.37.248]) by d06nrmr1806.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p0R8Uv011699962 for ; Thu, 27 Jan 2011 08:30:57 GMT Received: from d06av07.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av07.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p0R8UrdW016002 for ; Thu, 27 Jan 2011 01:30:54 -0700 Received: from rice.haifa.ibm.com (rice.haifa.ibm.com [9.148.8.217]) by d06av07.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p0R8Uqma015971 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 27 Jan 2011 01:30:53 -0700 Received: from rice.haifa.ibm.com (lnx-nyh.haifa.ibm.com [127.0.0.1]) by rice.haifa.ibm.com (8.14.4/8.14.4) with ESMTP id p0R8UqYY002393; Thu, 27 Jan 2011 10:30:52 +0200 Received: (from nyh@localhost) by rice.haifa.ibm.com (8.14.4/8.14.4/Submit) id p0R8UpYL002391; Thu, 27 Jan 2011 10:30:51 +0200 Date: Thu, 27 Jan 2011 10:30:51 +0200 Message-Id: <201101270830.p0R8UpYL002391@rice.haifa.ibm.com> X-Authentication-Warning: rice.haifa.ibm.com: nyh set sender to "Nadav Har'El" using -f Cc: gleb@redhat.com, avi@redhat.com To: kvm@vger.kernel.org From: "Nadav Har'El" References: <1296116987-nyh@il.ibm.com> Subject: [PATCH 02/29] nVMX: Implement VMXON and VMXOFF 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-4.2.6 (demeter1.kernel.org [140.211.167.41]); Thu, 27 Jan 2011 08:30:59 +0000 (UTC) --- .before/arch/x86/kvm/vmx.c 2011-01-26 18:06:02.000000000 +0200 +++ .after/arch/x86/kvm/vmx.c 2011-01-26 18:06:02.000000000 +0200 @@ -130,6 +130,17 @@ struct shared_msr_entry { u64 mask; }; +/* + * The nested_vmx structure is part of vcpu_vmx, and holds information we need + * for correct emulation of VMX (i.e., nested VMX) on this vcpu. For example, + * the current VMCS set by L1, a list of the VMCSs used to run the active + * L2 guests on the hardware, and more. + */ +struct nested_vmx { + /* Has the level1 guest done vmxon? */ + bool vmxon; +}; + struct vcpu_vmx { struct kvm_vcpu vcpu; struct list_head local_vcpus_link; @@ -177,6 +188,9 @@ struct vcpu_vmx { u32 exit_reason; bool rdtscp_enabled; + + /* Support for a guest hypervisor (nested VMX) */ + struct nested_vmx nested; }; static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu) @@ -3758,6 +3772,99 @@ static int handle_invalid_op(struct kvm_ } /* + * Emulate the VMXON instruction. + * Currently, we just remember that VMX is active, and do not save or even + * inspect the argument to VMXON (the so-called "VMXON pointer") because we + * do not currently need to store anything in that guest-allocated memory + * region. Consequently, VMCLEAR and VMPTRLD also do not verify that the their + * argument is different from the VMXON pointer (which the spec says they do). + */ +static int handle_vmon(struct kvm_vcpu *vcpu) +{ + struct kvm_segment cs; + struct vcpu_vmx *vmx = to_vmx(vcpu); + + /* The Intel VMX Instruction Reference lists a bunch of bits that + * are prerequisite to running VMXON, most notably cr4.VMXE must be + * set to 1 (see vmx_set_cr4() for when we allow the guest to set this). + * Otherwise, we should fail with #UD. We test these now: + */ + if (!kvm_read_cr4_bits(vcpu, X86_CR4_VMXE) || + !kvm_read_cr0_bits(vcpu, X86_CR0_PE) || + (vmx_get_rflags(vcpu) & X86_EFLAGS_VM)) { + kvm_queue_exception(vcpu, UD_VECTOR); + return 1; + } + + vmx_get_segment(vcpu, &cs, VCPU_SREG_CS); + if (is_long_mode(vcpu) && !cs.l) { + kvm_queue_exception(vcpu, UD_VECTOR); + return 1; + } + + if (vmx_get_cpl(vcpu)) { + kvm_inject_gp(vcpu, 0); + return 1; + } + + vmx->nested.vmxon = true; + + skip_emulated_instruction(vcpu); + return 1; +} + +/* + * Intel's VMX Instruction Reference specifies a common set of prerequisites + * for running VMX instructions (except VMXON, whose prerequisites are + * slightly different). It also specifies what exception to inject otherwise. + */ +static int nested_vmx_check_permission(struct kvm_vcpu *vcpu) +{ + struct kvm_segment cs; + struct vcpu_vmx *vmx = to_vmx(vcpu); + + if (!vmx->nested.vmxon) { + kvm_queue_exception(vcpu, UD_VECTOR); + return 0; + } + + vmx_get_segment(vcpu, &cs, VCPU_SREG_CS); + if ((vmx_get_rflags(vcpu) & X86_EFLAGS_VM) || + (is_long_mode(vcpu) && !cs.l)) { + kvm_queue_exception(vcpu, UD_VECTOR); + return 0; + } + + if (vmx_get_cpl(vcpu)) { + kvm_inject_gp(vcpu, 0); + return 0; + } + + return 1; +} + +/* + * Free whatever needs to be freed from vmx->nested when L1 goes down, or + * just stops using VMX. + */ +static void free_nested(struct vcpu_vmx *vmx) +{ + if (!vmx->nested.vmxon) + return; + vmx->nested.vmxon = false; +} + +/* Emulate the VMXOFF instruction */ +static int handle_vmoff(struct kvm_vcpu *vcpu) +{ + if (!nested_vmx_check_permission(vcpu)) + return 1; + free_nested(to_vmx(vcpu)); + skip_emulated_instruction(vcpu); + return 1; +} + +/* * The exit handlers return 1 if the exit was handled fully and guest execution * may resume. Otherwise they set the kvm_run parameter to indicate what needs * to be done to userspace and return 0. @@ -3785,8 +3892,8 @@ static int (*kvm_vmx_exit_handlers[])(st [EXIT_REASON_VMREAD] = handle_vmx_insn, [EXIT_REASON_VMRESUME] = handle_vmx_insn, [EXIT_REASON_VMWRITE] = handle_vmx_insn, - [EXIT_REASON_VMOFF] = handle_vmx_insn, - [EXIT_REASON_VMON] = handle_vmx_insn, + [EXIT_REASON_VMOFF] = handle_vmoff, + [EXIT_REASON_VMON] = handle_vmon, [EXIT_REASON_TPR_BELOW_THRESHOLD] = handle_tpr_below_threshold, [EXIT_REASON_APIC_ACCESS] = handle_apic_access, [EXIT_REASON_WBINVD] = handle_wbinvd,