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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5915C004C0 for ; Mon, 23 Oct 2023 11:31:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234079AbjJWLbQ (ORCPT ); Mon, 23 Oct 2023 07:31:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234077AbjJWLbQ (ORCPT ); Mon, 23 Oct 2023 07:31:16 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64CBCC1 for ; Mon, 23 Oct 2023 04:31:14 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F20FC433C7; Mon, 23 Oct 2023 11:31:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698060674; bh=2GNCL/7jcQe397vdAZ3ulH10C+gBPq00n5/ORV14eqU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xtDwsRyFPyPwGr29TMMPS9dVvDfyycXEjfrnIuqHFhflqyOq7QyrCXKHDz9+IEhRU n76gC5nQMJc4i8OwPfu/ghQsQDMKqly1vZ4Ng8zQgbk0+bXRmZMRU0PsNkA8co9Aml 2JpilLuGoYP51wgI1FB/784BjLYUET1cxJ7X3N5k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jim Mattson , Mingwei Zhang , Sean Christopherson Subject: [PATCH 5.4 055/123] KVM: x86: Mask LVTPC when handling a PMI Date: Mon, 23 Oct 2023 12:56:53 +0200 Message-ID: <20231023104819.548890033@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231023104817.691299567@linuxfoundation.org> References: <20231023104817.691299567@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jim Mattson commit a16eb25b09c02a54c1c1b449d4b6cfa2cf3f013a upstream. Per the SDM, "When the local APIC handles a performance-monitoring counters interrupt, it automatically sets the mask flag in the LVT performance counter register." Add this behavior to KVM's local APIC emulation. Failure to mask the LVTPC entry results in spurious PMIs, e.g. when running Linux as a guest, PMI handlers that do a "late_ack" spew a large number of "dazed and confused" spurious NMI warnings. Fixes: f5132b01386b ("KVM: Expose a version 2 architectural PMU to a guests") Cc: stable@vger.kernel.org Signed-off-by: Jim Mattson Tested-by: Mingwei Zhang Signed-off-by: Mingwei Zhang Link: https://lore.kernel.org/r/20230925173448.3518223-3-mizhang@google.com [sean: massage changelog, correct Fixes] Signed-off-by: Sean Christopherson Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/lapic.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2244,13 +2244,17 @@ int kvm_apic_local_deliver(struct kvm_la { u32 reg = kvm_lapic_get_reg(apic, lvt_type); int vector, mode, trig_mode; + int r; if (kvm_apic_hw_enabled(apic) && !(reg & APIC_LVT_MASKED)) { vector = reg & APIC_VECTOR_MASK; mode = reg & APIC_MODE_MASK; trig_mode = reg & APIC_LVT_LEVEL_TRIGGER; - return __apic_accept_irq(apic, mode, vector, 1, trig_mode, - NULL); + + r = __apic_accept_irq(apic, mode, vector, 1, trig_mode, NULL); + if (r && lvt_type == APIC_LVTPC) + kvm_lapic_set_reg(apic, APIC_LVTPC, reg | APIC_LVT_MASKED); + return r; } return 0; }