From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MdMCN-0004qk-LR for qemu-devel@nongnu.org; Tue, 18 Aug 2009 06:45:52 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MdMCH-0004nU-Vg for qemu-devel@nongnu.org; Tue, 18 Aug 2009 06:45:50 -0400 Received: from [199.232.76.173] (port=52236 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MdMCH-0004nA-M8 for qemu-devel@nongnu.org; Tue, 18 Aug 2009 06:45:45 -0400 Received: from os.inf.tu-dresden.de ([141.76.48.99]:50921) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MdMCH-0000Yw-72 for qemu-devel@nongnu.org; Tue, 18 Aug 2009 06:45:45 -0400 Date: Tue, 18 Aug 2009 11:39:54 +0200 From: Bernhard Kauer Subject: Re: [Qemu-devel] i8259 defaults wrong? Message-ID: <20090818093932.GA1887@chrom.inf.tu-dresden.de> References: <20090817022024.GE1025@MAIL.13thfloor.at> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090817022024.GE1025@MAIL.13thfloor.at> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: kvm@vger.kernel.org, qemu-devel@nongnu.org On Mon, Aug 17, 2009 at 04:20:24AM +0200, Herbert Poetzl wrote: > looking at the i8259 implementation found in qemu > as well as in the in-kernel kvm implementation, I > see that on pic_reset() special_fully_nested_mode > is set to zero, but the intel(r) 8259A manual says > on page 15: > > Fully Nested Mode > > This mode is entered after initialization unless > another mode is programmed. > > any comments are appreciated, You confuse two modes of the PIC: the FullyNestedMode and the SpecialFullyNestedMode. See page 18 in the manual. The first ist the "default" mode, where an IRQ in service from a slave masks further interrupts from this slave. In SFNM a slave PIC can still issue another IRQ. Greetings, Bernhard Kauer