From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ladi Prosek Subject: [PATCH 2/5] KVM: nVMX: fix SMI injection in guest mode Date: Wed, 13 Sep 2017 16:06:25 +0200 Message-ID: <20170913140628.7787-3-lprosek@redhat.com> References: <20170913140628.7787-1-lprosek@redhat.com> Cc: rkrcmar@redhat.com To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:38312 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751803AbdIMOGk (ORCPT ); Wed, 13 Sep 2017 10:06:40 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C5CEC4ACCA for ; Wed, 13 Sep 2017 14:06:39 +0000 (UTC) In-Reply-To: <20170913140628.7787-1-lprosek@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Entering SMM while running in guest mode wasn't working very well because several pieces of the vcpu state were left set up for nested operation. Some of the issues observed: * L1 was getting unexpected VM exits (using L1 interception controls but running in SMM execution environment) * SMM handler couldn't write to vmx_set_cr4 because of incorrect validity checks predicated on nested.vmxon * MMU was confused (walk_mmu was still set to nested_mmu) Intel SDM actually prescribes the logical processor to "leave VMX operation" upon entering SMM in 34.14.1 Default Treatment of SMI Delivery. What we need to do is basically get out of guest mode and set nested.vmxon to false for the duration of SMM. All this completely transparent to L1, i.e. L1 is not given control and no L1 observable state changes. To avoid code duplication this commit takes advantage of the existing nested vmexit and run functionality, perhaps at the cost of efficiency. To get out of guest mode, nested_vmx_vmexit with exit_reason == -1 is called, a trick already used in vmx_leave_nested. Re-entering is cleaner, using enter_vmx_non_root_mode. This commit fixes running Windows Server 2016 with Hyper-V enabled in a VM with OVMF firmware (OVMF_CODE-need-smm.fd). Signed-off-by: Ladi Prosek --- arch/x86/kvm/vmx.c | 55 +++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 44 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d56a528..4926df2 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -481,6 +481,14 @@ struct nested_vmx { u64 nested_vmx_cr4_fixed0; u64 nested_vmx_cr4_fixed1; u64 nested_vmx_vmcs_enum; + + /* SMM related state */ + struct { + /* in VMX operation on SMM entry? */ + bool vmxon; + /* in guest mode on SMM entry? */ + bool guest_mode; + } smm; }; #define POSTED_INTR_ON 0 @@ -11112,8 +11120,11 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, WARN_ON_ONCE(vmx->nested.nested_run_pending); leave_guest_mode(vcpu); - prepare_vmcs12(vcpu, vmcs12, exit_reason, exit_intr_info, - exit_qualification); + if (exit_reason == -1) + sync_vmcs12(vcpu, vmcs12); + else + prepare_vmcs12(vcpu, vmcs12, exit_reason, exit_intr_info, + exit_qualification); if (nested_vmx_store_msr(vcpu, vmcs12->vm_exit_msr_store_addr, vmcs12->vm_exit_msr_store_count)) @@ -11139,12 +11150,13 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR; } - trace_kvm_nested_vmexit_inject(vmcs12->vm_exit_reason, - vmcs12->exit_qualification, - vmcs12->idt_vectoring_info_field, - vmcs12->vm_exit_intr_info, - vmcs12->vm_exit_intr_error_code, - KVM_ISA_VMX); + if (exit_reason != -1) + trace_kvm_nested_vmexit_inject(vmcs12->vm_exit_reason, + vmcs12->exit_qualification, + vmcs12->idt_vectoring_info_field, + vmcs12->vm_exit_intr_info, + vmcs12->vm_exit_intr_error_code, + KVM_ISA_VMX); vm_entry_controls_reset_shadow(vmx); vm_exit_controls_reset_shadow(vmx); @@ -11214,7 +11226,7 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, nested_vmx_failValid(vcpu, vm_inst_error); } else nested_vmx_succeed(vcpu); - if (enable_shadow_vmcs) + if (enable_shadow_vmcs && exit_reason != -1) vmx->nested.sync_shadow_vmcs = true; /* in case we halted in L2 */ @@ -11631,13 +11643,34 @@ static void vmx_setup_mce(struct kvm_vcpu *vcpu) static int vmx_prep_enter_smm(struct kvm_vcpu *vcpu, char *smstate) { - /* TODO: Implement */ + struct vcpu_vmx *vmx = to_vmx(vcpu); + + vmx->nested.smm.guest_mode = is_guest_mode(vcpu); + if (vmx->nested.smm.guest_mode) + nested_vmx_vmexit(vcpu, -1, 0, 0); + + vmx->nested.smm.vmxon = vmx->nested.vmxon; + vmx->nested.vmxon = false; return 0; } static int vmx_post_leave_smm(struct kvm_vcpu *vcpu) { - /* TODO: Implement */ + struct vcpu_vmx *vmx = to_vmx(vcpu); + int ret; + + if (vmx->nested.smm.vmxon) { + vmx->nested.vmxon = true; + vmx->nested.smm.vmxon = false; + } + + if (vmx->nested.smm.guest_mode) { + ret = enter_vmx_non_root_mode(vcpu, false); + if (ret) + return ret; + + vmx->nested.smm.guest_mode = false; + } return 0; } -- 2.9.3