From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:58413) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RzNpO-0007Ax-2w for qemu-devel@nongnu.org; Mon, 20 Feb 2012 02:38:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RzNpI-0001XZ-4E for qemu-devel@nongnu.org; Mon, 20 Feb 2012 02:38:30 -0500 Received: from mail-ey0-f173.google.com ([209.85.215.173]:36438) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RzNpH-0001XU-W1 for qemu-devel@nongnu.org; Mon, 20 Feb 2012 02:38:24 -0500 Received: by eaac1 with SMTP id c1so2288826eaa.4 for ; Sun, 19 Feb 2012 23:38:22 -0800 (PST) Sender: Paolo Bonzini Message-ID: <4F41F86C.8010801@redhat.com> Date: Mon, 20 Feb 2012 08:38:20 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 2/4] RTC:Add RTC update-ended interrupt logic List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Zhang, Yang Z" Cc: "aliguori@us.ibm.com" , Marcelo Tosatti , Jan Kiszka , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" On 02/20/2012 01:25 AM, Zhang, Yang Z wrote: > Use timer to emulate RTC update-ended interrupt. The timer is enabled > only when UIE is setting. The timer needs to be enabled when UF is clear, not when UIE is set. If UIE is set but the update interrupt is masked you do not need to do anything; on the other hand you need to update UF in case the guest is observing interrupts with polling. Paolo