From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 7F9DBC55186 for ; Fri, 24 Apr 2020 17:25:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51FBD20704 for ; Fri, 24 Apr 2020 17:25:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HH8QSmH0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728871AbgDXRYj (ORCPT ); Fri, 24 Apr 2020 13:24:39 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:29678 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726849AbgDXRYg (ORCPT ); Fri, 24 Apr 2020 13:24:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587749075; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=n/v+GecTrEwyyLbsd1WvGrx2OwR9+bmxfRFtapBWds8=; b=HH8QSmH0cHNQwf8PBeYFmYzB1DFrYqqWqWo+HhzxED8ccbdlpivnCPxpeZ0ffJP6XLzNxp ctpnuNDjKZCkHi8P+qFObtKFNJRxCddpDGKqMc+FOYZ6Tu9zdXuE1BEUVPOWQd8CDNn7dI jGijwMiKXb1CJ1Icude3jS/V44MPcOs= 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-401-V_LEgpmoPRuvE8EGmhtFdQ-1; Fri, 24 Apr 2020 13:24:33 -0400 X-MC-Unique: V_LEgpmoPRuvE8EGmhtFdQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 28603A73A7; Fri, 24 Apr 2020 17:24:25 +0000 (UTC) Received: from virtlab511.virt.lab.eng.bos.redhat.com (virtlab511.virt.lab.eng.bos.redhat.com [10.19.152.198]) by smtp.corp.redhat.com (Postfix) with ESMTP id 280D91FDE1; Fri, 24 Apr 2020 17:24:24 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: wei.huang2@amd.com, cavery@redhat.com, vkuznets@redhat.com, Sean Christopherson , Oliver Upton , Jim Mattson , Peter Shier Subject: [PATCH v2 06/22] KVM: nVMX: Open a window for pending nested VMX preemption timer Date: Fri, 24 Apr 2020 13:24:00 -0400 Message-Id: <20200424172416.243870-7-pbonzini@redhat.com> In-Reply-To: <20200424172416.243870-1-pbonzini@redhat.com> References: <20200424172416.243870-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sean Christopherson Add a kvm_x86_ops hook to detect a nested pending "hypervisor timer" and use it to effectively open a window for servicing the expired timer. Like pending SMIs on VMX, opening a window simply means requesting an immediate exit. This fixes a bug where an expired VMX preemption timer (for L2) will be delayed and/or lost if a pending exception is injected into L2. The pending exception is rightly prioritized by vmx_check_nested_events() and injected into L2, with the preemption timer left pending. Because no window opened, L2 is free to run uninterrupted. Fixes: f4124500c2c13 ("KVM: nVMX: Fully emulate preemption timer") Reported-by: Jim Mattson Cc: Oliver Upton Cc: Peter Shier Signed-off-by: Sean Christopherson Message-Id: <20200423022550.15113-3-sean.j.christopherson@intel.com> [Check it in kvm_vcpu_has_events too, to ensure that the preemption timer is serviced promptly even if the vCPU is halted and L1 is not intercepting HLT. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/vmx/nested.c | 10 ++++++++-- arch/x86/kvm/x86.c | 9 +++++++++ 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a239a297be33..372e6ea4af32 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1257,6 +1257,7 @@ struct kvm_x86_ops { struct kvm_x86_nested_ops { int (*check_events)(struct kvm_vcpu *vcpu); + bool (*hv_timer_pending)(struct kvm_vcpu *vcpu); int (*get_state)(struct kvm_vcpu *vcpu, struct kvm_nested_state __user *user_kvm_nested_state, unsigned user_data_size); diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 490dba7d0504..182e5209a1f6 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3687,6 +3687,12 @@ static void nested_vmx_update_pending_dbg(struct kvm_vcpu *vcpu) vcpu->arch.exception.payload); } +static bool nested_vmx_preemption_timer_pending(struct kvm_vcpu *vcpu) +{ + return nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) && + to_vmx(vcpu)->nested.preemption_timer_expired; +} + static int vmx_check_nested_events(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -3742,8 +3748,7 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu) return 0; } - if (nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) && - vmx->nested.preemption_timer_expired) { + if (nested_vmx_preemption_timer_pending(vcpu)) { if (block_nested_events) return -EBUSY; nested_vmx_vmexit(vcpu, EXIT_REASON_PREEMPTION_TIMER, 0, 0); @@ -6448,6 +6453,7 @@ __init int nested_vmx_hardware_setup(struct kvm_x86_ops *ops, struct kvm_x86_nested_ops vmx_nested_ops = { .check_events = vmx_check_nested_events, + .hv_timer_pending = nested_vmx_preemption_timer_pending, .get_state = vmx_get_nested_state, .set_state = vmx_set_nested_state, .get_vmcs12_pages = nested_get_vmcs12_pages, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8c0b77ac8dc6..ee934a88a267 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8324,6 +8324,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_x86_ops.enable_nmi_window(vcpu); if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win) kvm_x86_ops.enable_irq_window(vcpu); + if (is_guest_mode(vcpu) && + kvm_x86_ops.nested_ops->hv_timer_pending && + kvm_x86_ops.nested_ops->hv_timer_pending(vcpu)) + req_immediate_exit = true; WARN_ON(vcpu->arch.exception.pending); } @@ -10179,6 +10183,11 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu) if (kvm_hv_has_stimer_pending(vcpu)) return true; + if (is_guest_mode(vcpu) && + kvm_x86_ops.nested_ops->hv_timer_pending && + kvm_x86_ops.nested_ops->hv_timer_pending(vcpu)) + return true; + return false; } -- 2.18.2