From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:56180) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UceUQ-0004Ba-Oj for qemu-devel@nongnu.org; Wed, 15 May 2013 12:23:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UceUO-0003RV-00 for qemu-devel@nongnu.org; Wed, 15 May 2013 12:23:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7985) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UceUN-0003RQ-O6 for qemu-devel@nongnu.org; Wed, 15 May 2013 12:23:39 -0400 Message-ID: <5193B705.5020905@redhat.com> Date: Wed, 15 May 2013 18:25:41 +0200 From: Laszlo Ersek MIME-Version: 1.0 References: <1365146271-6220-1-git-send-email-hutao@cn.fujitsu.com> <51933792.7030700@redhat.com> <20130515072739.GA30450@localhost.localdomain> In-Reply-To: <20130515072739.GA30450@localhost.localdomain> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [SeaBIOS] [PATCH v17] Add pvpanic device driver List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Hu Tao , Paolo Bonzini Cc: Peter Maydell , Gleb Natapov , "Michael S. Tsirkin" , Jan Kiszka , seabios@seabios.org, qemu-devel , Markus Armbruster , Blue Swirl , Orit Wasserman , Juan Quintela , Alexander Graf , Christian Borntraeger , Drew Jones , Alex Williamson , Kevin O'Connor , Sasha Levin , Stefan Hajnoczi , Luiz Capitulino , KAMEZAWA Hiroyuki , Anthony Liguori , Marcelo Tosatti (Not sure why the CC list has grown this huge, but I'm adding Drew for good mesaure.) On 05/15/13 09:27, Hu Tao wrote: > On Wed, May 15, 2013 at 09:21:54AM +0200, Laszlo Ersek wrote: >> On 04/05/13 09:17, Hu Tao wrote: >> >>> + Method(RDPT, 0, NotSerialized) { >>> + Store(PEPT, Local0) >>> + Return (Local0) >>> + } >>> + >>> + Method(WRPT, 1, NotSerialized) { >>> + Store(Arg0, PEPT) >>> + } >> >> Please excuse my asking, I haven't been following this -- who's supposed >> to call these methods? The latest guest kernel patch I managed to find >> ([PATCH v7] kvm: notify host when the guest is panicked -- probably >> obsolete by now) appears to do a direct outl(). > > An old version calls WRPT but is buggy, so you see the outl version. > This patch is in seabios before the outl version. If you think these > methods are needless, feel free to send a patch. After Drew located the guest kernel commit for me, http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=8b10acd7 I can see this SeaBIOS patch *is* necessary -- even though the RDPT / WRPT methods are not used for port access, the port number itself is available from ACPI (\_SB.PCI0.ISA.PEVT._CRS, identified by the "QEMU0001" HID) to the kernel. Hu, can you (and are you willing to) relicense this commit (seabios commit e9725dd7) under the 2-clause BSDL so I can port it to OVMF? (Actually I'm somewhat confused because the first S-o-b is from Paolo. Since I share an employer with Paolo, getting permission from Paolo would be either quite easy or even unnecessary. Anyway it's better to ask!) Thanks, Laszlo