From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [patch 0/2] fix lapic_timer_advance_ns guest triggerable unlimited delays Date: Tue, 21 Jun 2016 09:53:06 +0200 Message-ID: <0a96eb3f-341d-aed0-7795-25fc512b134f@redhat.com> References: <20160621012801.145630514@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: Radim Krcmar , Alan Jenkins To: Marcelo Tosatti , kvm@vger.kernel.org Return-path: Received: from mail-lb0-f195.google.com ([209.85.217.195]:35086 "EHLO mail-lb0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751209AbcFUIWW (ORCPT ); Tue, 21 Jun 2016 04:22:22 -0400 Received: by mail-lb0-f195.google.com with SMTP id td3so928724lbb.2 for ; Tue, 21 Jun 2016 01:21:34 -0700 (PDT) In-Reply-To: <20160621012801.145630514@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 21/06/2016 03:28, Marcelo Tosatti wrote: > The host timer which emulates the guest LAPIC TSC deadline > timer has its expiration diminished by lapic_timer_advance_ns > nanoseconds. Therefore if, at wait_lapic_expire, a difference > larger than lapic_timer_advance_ns is encountered, delay at most > lapic_timer_advance_ns. > > This fixes a problem where the guest can cause the host > to delay for large amounts of time. > > Thanks to Alan Jenkins for reporting. Applying to kvm/master, thanks. Paolo