From nobody Sun Feb 8 21:55:45 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB434C433EF for ; Mon, 27 Jun 2022 21:59:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242195AbiF0V7R (ORCPT ); Mon, 27 Jun 2022 17:59:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241553AbiF0Vzq (ORCPT ); Mon, 27 Jun 2022 17:55:46 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B38B71114A; Mon, 27 Jun 2022 14:55:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656366903; x=1687902903; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=yzehMGTZgz4slH2Wlmj2VzOPlB1rDEa+xprmlhmf7Vc=; b=ggw5WfDdorOZp0pVM3LQ2JgV6sO2mgMU1txPXpKZdvGcN2wJzFk0O5LW MA7jlGvBQrjF4xj3BSCJSCR4itS77ftNMvFlCGQfFUqzzJEfba7yeC9Go N3cbeNyiLESHauCJZKbQ8DPnKlChHy2RgEIxb8hxf7yJdeKixcevB9X6g QZ5uuIMh/h8OQnXI04jRQb5tTXtbD11SuEM7jMedcx+wdr1NV2esdnBpu /bnZjJkrYbSJ0dolBv1Ng2V90yznxs0D2v2ffspf6bLiotFD2CFIGdWTb dXjHxpZAxVybiBrSvNpKcaWaZLqsdKQVdtD2bAAHuyv5f5uIQh+hhKA+2 A==; X-IronPort-AV: E=McAfee;i="6400,9594,10391"; a="279116119" X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="279116119" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 14:54:59 -0700 X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="657863681" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 14:54:59 -0700 From: isaku.yamahata@intel.com To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Paolo Bonzini , Sean Christopherson Subject: [PATCH v7 075/102] KVM: x86: Assume timer IRQ was injected if APIC state is proteced Date: Mon, 27 Jun 2022 14:54:07 -0700 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Sean Christopherson If APIC state is protected, i.e. the vCPU is a TDX guest, assume a timer IRQ was injected when deciding whether or not to busy wait in the "timer advanced" path. The "real" vIRR is not readable/writable, so trying to query for a pending timer IRQ will return garbage. Note, TDX can scour the PIR if it wants to be more precise and skip the "wait" call entirely. Signed-off-by: Sean Christopherson --- arch/x86/kvm/lapic.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index c85ed9f6a8c9..707f1ff90f8a 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1578,8 +1578,17 @@ static void apic_update_lvtt(struct kvm_lapic *apic) static bool lapic_timer_int_injected(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic =3D vcpu->arch.apic; - u32 reg =3D kvm_lapic_get_reg(apic, APIC_LVTT); + u32 reg; =20 + /* + * Assume a timer IRQ was "injected" if the APIC is protected. KVM's + * copy of the vIRR is bogus, it's the responsibility of the caller to + * precisely check whether or not a timer IRQ is pending. + */ + if (apic->guest_apic_protected) + return true; + + reg =3D kvm_lapic_get_reg(apic, APIC_LVTT); if (kvm_apic_hw_enabled(apic)) { int vec =3D reg & APIC_VECTOR_MASK; void *bitmap =3D apic->regs + APIC_ISR; --=20 2.25.1