From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nadav Har'El" Subject: Re: [PATCH 9/24] Implement VMCLEAR Date: Thu, 5 Aug 2010 15:29:27 +0300 Message-ID: <20100805122927.GA24590@fermat.math.technion.ac.il> References: <201006131227.o5DCRAB0012968@rice.haifa.ibm.com> <20100615134753.GX21797@redhat.com> <4C17852B.5080703@redhat.com> <20100615135405.GY21797@redhat.com> <20100805115025.GC16722@fermat.math.technion.ac.il> <20100805115304.GL10499@redhat.com> <20100805120136.GD16722@fermat.math.technion.ac.il> <4C5AA911.4040405@redhat.com> <20100805121027.GE16722@fermat.math.technion.ac.il> <4C5AAACC.7040400@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Gleb Natapov , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mailgw12.technion.ac.il ([132.68.225.12]:4478 "EHLO mailgw12.technion.ac.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756027Ab0HEM3c (ORCPT ); Thu, 5 Aug 2010 08:29:32 -0400 Content-Disposition: inline In-Reply-To: <4C5AAACC.7040400@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Aug 05, 2010, Avi Kivity wrote about "Re: [PATCH 9/24] Implement VMCLEAR": > >Do you think it's a good idea to kill > >the guest immediately, in anticipation of a crash that will most likely > >come > >later? > > At this stage, the problem is likely to be in the nvmx implementation. > So it's best to report the problem as early as possible. Ok, here is the new version of this patch, implementing this case by doing a triple fault (I hope this is what you meant by KVM_REQ_SHUTDOWN), and also with other fixes as suggested by you, Gleb and Eddie. ---- Subject: [PATCH 10/26] nVMX: Implement VMCLEAR This patch implements the VMCLEAR instruction. Signed-off-by: Nadav Har'El --- arch/x86/kvm/vmx.c | 62 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 61 insertions(+), 1 deletion(-) --- .before/arch/x86/kvm/vmx.c 2010-08-05 15:22:27.000000000 +0300 +++ .after/arch/x86/kvm/vmx.c 2010-08-05 15:22:27.000000000 +0300 @@ -144,6 +144,8 @@ struct __packed vmcs12 { */ u32 revision_id; u32 abort; + + bool launch_state; /* set to 0 by VMCLEAR, to 1 by VMLAUNCH */ }; /* @@ -3828,6 +3830,64 @@ static void nested_vmx_failValid(struct get_vmcs12_fields(vcpu)->vm_instruction_error = vm_instruction_error; } +/* Emulate the VMCLEAR instruction */ +static int handle_vmclear(struct kvm_vcpu *vcpu) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + gva_t gva; + gpa_t vmcs12_addr; + struct vmcs12 *vmcs12; + struct page *page; + + if (!nested_vmx_check_permission(vcpu)) + return 1; + + if (get_vmx_mem_address(vcpu, vmcs_readl(EXIT_QUALIFICATION), + vmcs_read32(VMX_INSTRUCTION_INFO), &gva)) + return 1; + + if (kvm_read_guest_virt(gva, &vmcs12_addr, sizeof(vmcs12_addr), + vcpu, NULL)) { + kvm_queue_exception(vcpu, PF_VECTOR); + return 1; + } + + if (!IS_ALIGNED(vmcs12_addr, PAGE_SIZE)) { + nested_vmx_failValid(vcpu, VMXERR_VMCLEAR_INVALID_ADDRESS); + skip_emulated_instruction(vcpu); + return 1; + } + + if (vmcs12_addr == vmx->nested.current_vmptr){ + kunmap(vmx->nested.current_vmcs12_page); + nested_release_page(vmx->nested.current_vmcs12_page); + vmx->nested.current_vmptr = -1ull; + } + + page = nested_get_page(vcpu, vmcs12_addr); + if(page == NULL){ + /* + * For accurate processor emulation, VMCLEAR beyond available + * physical memory should do nothing at all. However, it is + * possible that a nested vmx bug, not a guest hypervisor bug, + * resulted in this case, so let's shut down before doing any + * more damage: + */ + set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests); + return 1; + } + vmcs12 = kmap(page); + vmcs12->launch_state = 0; + kunmap(page); + nested_release_page(page); + + nested_free_vmcs(vcpu, vmcs12_addr); + + skip_emulated_instruction(vcpu); + nested_vmx_succeed(vcpu); + return 1; +} + static int handle_invlpg(struct kvm_vcpu *vcpu) { unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION); @@ -4110,7 +4170,7 @@ static int (*kvm_vmx_exit_handlers[])(st [EXIT_REASON_HLT] = handle_halt, [EXIT_REASON_INVLPG] = handle_invlpg, [EXIT_REASON_VMCALL] = handle_vmcall, - [EXIT_REASON_VMCLEAR] = handle_vmx_insn, + [EXIT_REASON_VMCLEAR] = handle_vmclear, [EXIT_REASON_VMLAUNCH] = handle_vmx_insn, [EXIT_REASON_VMPTRLD] = handle_vmx_insn, [EXIT_REASON_VMPTRST] = handle_vmx_insn, -- Nadav Har'El | Thursday, Aug 5 2010, 25 Av 5770 nyh@math.technion.ac.il |----------------------------------------- Phone +972-523-790466, ICQ 13349191 |A fine is a tax for doing wrong. A tax is http://nadav.harel.org.il |a fine for doing well.