From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zachary Amsden Subject: Re: [PATCH 4/7] Allow selected bug checks to be skipped by paravirt kernels Date: Wed, 01 Nov 2006 15:24:44 -0800 Message-ID: <45492CBC.8020501@vmware.com> References: <20061029024504.760769000@sous-sol.org> <20061029024606.496399000@sous-sol.org> <20061101121753.GA2205@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20061101121753.GA2205@elf.ucw.cz> Sender: linux-kernel-owner@vger.kernel.org To: Pavel Machek Cc: Chris Wright , akpm@osdl.org, ak@muc.de, Rusty Russell , Jeremy Fitzhardinge , linux-kernel@vger.kernel.org, virtualization@lists.osdl.org List-Id: virtualization@lists.linuxfoundation.org Pavel Machek wrote: > On Sat 2006-10-28 00:00:04, Chris Wright wrote: > >> Allow selected bug checks to be skipped by paravirt kernels. The two most >> important are the F00F workaround (which is either done by the hypervisor, >> or not required), and the 'hlt' instruction check, which can break under >> some hypervisors. >> > > How can hlt check break? It is hlt;hlt;hlt, IIRC, that looks fairly > innocent to me. > Not if you use tickless timers that don't generate interrupts to unhalt you, or if you delay ticks until the next scheduled timeout and you haven't yet scheduled any timeout. Both are likely in a hypervisor. Zach