From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH v3 5/6] KVM: nVMX: Update mmu.base_role.nxe after EFER loading on VM-entry/exit Date: Tue, 03 Sep 2013 10:51:31 +0200 Message-ID: <5225A313.1070700@siemens.com> References: <08db7d166ab05ce133300ba069c0728f5c97120b.1375971992.git.jan.kiszka@siemens.com> <20130903083939.GV22899@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Paolo Bonzini , kvm , Xiao Guangrong , Jun Nakajima , Yang Zhang , Arthur Chunqi Li To: Gleb Natapov Return-path: Received: from thoth.sbs.de ([192.35.17.2]:26378 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759537Ab3ICIvn (ORCPT ); Tue, 3 Sep 2013 04:51:43 -0400 In-Reply-To: <20130903083939.GV22899@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2013-09-03 10:39, Gleb Natapov wrote: > On Thu, Aug 08, 2013 at 04:26:32PM +0200, Jan Kiszka wrote: >> This job is normally performed by the architectural EFER set service >> which we cannot use as it prevents transitions that are valid when >> switching between L1 and L2. So open-code the update of base_role.nxe >> after changing EFER on VM-entry and exit. >> >> Signed-off-by: Jan Kiszka >> --- >> arch/x86/kvm/vmx.c | 4 ++++ >> 1 files changed, 4 insertions(+), 0 deletions(-) >> >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 9b0510b..7cc208a 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -7735,6 +7735,8 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) >> vcpu->arch.efer &= ~(EFER_LMA | EFER_LME); >> /* Note: modifies VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */ >> vmx_set_efer(vcpu, vcpu->arch.efer); >> + vcpu->arch.mmu.base_role.nxe = >> + (vcpu->arch.efer & EFER_NX) && !enable_ept; >> > kvm_mmu_reset_context() called later in this function does that. For all relevant scenarios? The code is pretty convoluted, so this is non-obvious for me: kvm_mmu_reset_context calls init_kvm_mmu which may call init_kvm_softmmu that does kvm_init_shadow_mmu with nxe initialization. But is that path always taken? Jan > >> if (nested_cpu_has_ept(vmcs12)) { >> kvm_mmu_unload(vcpu); >> @@ -8179,6 +8181,8 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu, >> else >> vcpu->arch.efer &= ~(EFER_LMA | EFER_LME); >> vmx_set_efer(vcpu, vcpu->arch.efer); >> + vcpu->arch.mmu.base_role.nxe = >> + (vcpu->arch.efer & EFER_NX) && !enable_ept; >> > Same here. > >> kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->host_rsp); >> kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->host_rip); >> -- >> 1.7.3.4 > > -- > Gleb. > -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux