From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41351) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1Sas-0001h4-5f for qemu-devel@nongnu.org; Mon, 22 Jul 2013 22:44:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V1Sar-0001IC-At for qemu-devel@nongnu.org; Mon, 22 Jul 2013 22:44:54 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:31784) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1Saq-0001HU-NX for qemu-devel@nongnu.org; Mon, 22 Jul 2013 22:44:53 -0400 Message-ID: <51EDEE20.4060206@huawei.com> Date: Tue, 23 Jul 2013 10:44:48 +0800 From: "Peter Huang(Peng)" MIME-Version: 1.0 References: <51ED1668.7030205@huawei.com> <20130722134138.GE19826@otherpad.lan.raisama.net> In-Reply-To: <20130722134138.GE19826@otherpad.lan.raisama.net> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Question] why x2apic's set by default without host support(on Nehalem CPU). List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: libvir-list@redhat.com, qemu-devel@nongnu.org > libvirt's "host-passthrough" uses "-cpu host', and it "-cpu host" > enables every feature that can be enabled on the host. >>From my test results, I found that even when use host-passthrough mode, VM's cpu features are very different from host, this doesn't match what host-passthrough mode's explanation. libvirt's option exlanation: With this mode, the CPU visible to the guest should be exactly the same as the host CPU even in the aspects that libvirt does not understand. > If the behavior of "-cpu host" doesn't match libvirt expectations, we > need to clarify what are the requirements, and maybe have a "try to be > close to host CPU mode" as opposed to the current "enable everything > that can be enabled" mode. Does the results above indicates what you mean to do? or the current way doesn't work as we expect. Thanks!