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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 A4DDAC10F13 for ; Tue, 16 Apr 2019 17:49:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A84920663 for ; Tue, 16 Apr 2019 17:49:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730230AbfDPRtD (ORCPT ); Tue, 16 Apr 2019 13:49:03 -0400 Received: from mga06.intel.com ([134.134.136.31]:25055 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728809AbfDPRtC (ORCPT ); Tue, 16 Apr 2019 13:49:02 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Apr 2019 10:49:02 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,358,1549958400"; d="scan'208";a="224069833" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.181]) by orsmga001.jf.intel.com with ESMTP; 16 Apr 2019 10:49:02 -0700 From: Sean Christopherson To: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Cc: kvm@vger.kernel.org, Liran Alon , Wanpeng Li Subject: [PATCH v2 5/7] KVM: lapic: Busy wait for timer to expire when using hv_timer Date: Tue, 16 Apr 2019 10:48:55 -0700 Message-Id: <20190416174857.506-6-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190416174857.506-1-sean.j.christopherson@intel.com> References: <20190416174857.506-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org ...now that VMX's preemption timer, i.e. the hv_timer, also adjusts its programmed time based on lapic_timer_advance_ns. Without the delay, a guest can see a timer interrupt arrive before the requested time when KVM is using the hv_timer to emulate the guest's interrupt. Fixes: c5ce8235cffa0 ("KVM: VMX: Optimize tscdeadline timer latency") Cc: Cc: Wanpeng Li Reviewed-by: Liran Alon Signed-off-by: Sean Christopherson --- arch/x86/kvm/lapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 37d3489f68c9..fa2dbca5ad6a 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1455,7 +1455,7 @@ static void apic_timer_expired(struct kvm_lapic *apic) if (swait_active(q)) swake_up_one(q); - if (apic_lvtt_tscdeadline(apic)) + if (apic_lvtt_tscdeadline(apic) || ktimer->hv_timer_in_use) ktimer->expired_tscdeadline = ktimer->tscdeadline; } -- 2.21.0