From patchwork Mon May 17 13:50:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12262037 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8119BC433B4 for ; Mon, 17 May 2021 13:51:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 660F6611C2 for ; Mon, 17 May 2021 13:51:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237568AbhEQNwX (ORCPT ); Mon, 17 May 2021 09:52:23 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:28837 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234049AbhEQNwW (ORCPT ); Mon, 17 May 2021 09:52:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621259465; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N/5KkPOa7BDmJ61fDZWG5U+qX0pyk+buTzYClLDRiEU=; b=c6Zs9MTBvv89CPGkJ52eWDeyxKDslAz2tZTJMspn2vsGkw+OhXQO15S6LRyri6vcJXIyWy QDGUGbqdHarKjxZJF9n/OXCxHEh5ooySR2WjPzETTZ/T7lvvTBkDQeSJgB4IhmJJUnsFhZ RC3/OQtVHsgeIDRra23Tzak8UnTFpZM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-459-exbYJMcbPCW3WBQjIQk5Hg-1; Mon, 17 May 2021 09:51:02 -0400 X-MC-Unique: exbYJMcbPCW3WBQjIQk5Hg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4C69B8042A9; Mon, 17 May 2021 13:51:00 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.194.112]) by smtp.corp.redhat.com (Postfix) with ESMTP id 36B3F5C1A1; Mon, 17 May 2021 13:50:58 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Maxim Levitsky , linux-kernel@vger.kernel.org Subject: [PATCH v2 1/7] KVM: nVMX: Introduce nested_evmcs_is_used() Date: Mon, 17 May 2021 15:50:48 +0200 Message-Id: <20210517135054.1914802-2-vkuznets@redhat.com> In-Reply-To: <20210517135054.1914802-1-vkuznets@redhat.com> References: <20210517135054.1914802-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Unlike regular set_current_vmptr(), nested_vmx_handle_enlightened_vmptrld() can not be called directly from vmx_set_nested_state() as KVM may not have all the information yet (e.g. HV_X64_MSR_VP_ASSIST_PAGE MSR may not be restored yet). Enlightened VMCS is mapped later while getting nested state pages. In the meantime, vmx->nested.hv_evmcs remains NULL and using it for various checks is incorrect. In particular, if KVM_GET_NESTED_STATE is called right after KVM_SET_NESTED_STATE, KVM_STATE_NESTED_EVMCS flag in the resulting state will be unset (and such state will later fail to load). Introduce nested_evmcs_is_used() and use 'is_guest_mode(vcpu) && vmx->nested.current_vmptr == -1ull' check to detect not-yet-mapped eVMCS after restore. Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/vmx/nested.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 6058a65a6ede..3080e00c8f90 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -141,6 +141,27 @@ static void init_vmcs_shadow_fields(void) max_shadow_read_write_fields = j; } +static inline bool nested_evmcs_is_used(struct vcpu_vmx *vmx) +{ + struct kvm_vcpu *vcpu = &vmx->vcpu; + + if (vmx->nested.hv_evmcs) + return true; + + /* + * After KVM_SET_NESTED_STATE, enlightened VMCS is mapped during + * KVM_REQ_GET_NESTED_STATE_PAGES handling and until the request is + * processed vmx->nested.hv_evmcs is NULL. It is, however, possible to + * detect such state by checking 'nested.current_vmptr == -1ull' when + * vCPU is in guest mode, it is only possible with eVMCS. + */ + if (unlikely(vmx->nested.enlightened_vmcs_enabled && is_guest_mode(vcpu) && + (vmx->nested.current_vmptr == -1ull))) + return true; + + return false; +} + /* * The following 3 functions, nested_vmx_succeed()/failValid()/failInvalid(), * set the success or error code of an emulated VMX instruction (as specified @@ -187,7 +208,7 @@ static int nested_vmx_fail(struct kvm_vcpu *vcpu, u32 vm_instruction_error) * failValid writes the error number to the current VMCS, which * can't be done if there isn't a current VMCS. */ - if (vmx->nested.current_vmptr == -1ull && !vmx->nested.hv_evmcs) + if (vmx->nested.current_vmptr == -1ull && !nested_evmcs_is_used(vmx)) return nested_vmx_failInvalid(vcpu); return nested_vmx_failValid(vcpu, vm_instruction_error); @@ -2208,7 +2229,7 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) u32 exec_control; u64 guest_efer = nested_vmx_calc_efer(vmx, vmcs12); - if (vmx->nested.dirty_vmcs12 || vmx->nested.hv_evmcs) + if (vmx->nested.dirty_vmcs12 || nested_evmcs_is_used(vmx)) prepare_vmcs02_early_rare(vmx, vmcs12); /* @@ -3437,7 +3458,7 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, load_vmcs12_host_state(vcpu, vmcs12); vmcs12->vm_exit_reason = exit_reason.full; - if (enable_shadow_vmcs || vmx->nested.hv_evmcs) + if (enable_shadow_vmcs || nested_evmcs_is_used(vmx)) vmx->nested.need_vmcs12_to_shadow_sync = true; return NVMX_VMENTRY_VMEXIT; } @@ -4032,7 +4053,7 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) { struct vcpu_vmx *vmx = to_vmx(vcpu); - if (vmx->nested.hv_evmcs) + if (nested_evmcs_is_used(vmx)) sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12); vmx->nested.need_sync_vmcs02_to_vmcs12_rare = !vmx->nested.hv_evmcs; @@ -6056,7 +6077,7 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, if (vmx_has_valid_vmcs12(vcpu)) { kvm_state.size += sizeof(user_vmx_nested_state->vmcs12); - if (vmx->nested.hv_evmcs) + if (nested_evmcs_is_used(vmx)) kvm_state.flags |= KVM_STATE_NESTED_EVMCS; if (is_guest_mode(vcpu) &&