From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:47920) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ROSlO-00038X-1b for qemu-devel@nongnu.org; Thu, 10 Nov 2011 06:25:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ROSlN-00026n-0h for qemu-devel@nongnu.org; Thu, 10 Nov 2011 06:25:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:31542) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ROSlM-00026b-Ok for qemu-devel@nongnu.org; Thu, 10 Nov 2011 06:25:44 -0500 Message-ID: <4EBBB4B4.8030103@redhat.com> Date: Thu, 10 Nov 2011 12:25:40 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <4EBB3CD5.9050903@linux.vnet.ibm.com> <201111101305.40420.jcmvbkbc@gmail.com> <4EBB9632.8010605@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] x86_64 linux kernel doesn't boot with -icount enabled List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Filippov Cc: qemu-devel On 11/10/2011 11:25 AM, Max Filippov wrote: >> > >> > -icount should be ignored or give an error together with KVM. Would you > What's the background for that? (Unfortunately I'm completely > unfamiliar with kvm). > With -icount, The vm_clock is updated with help from TCG (it counts instructions at 2^ICOUNT ns/instructions). With KVM, the instruction count is not available so KVM cannot provide this help. The patch you sent looks good, but perhaps you can include the above comment in the commit message and also include Xen? With these changes, you can add my Acked-by. Thanks, Paolo