From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52694) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d2jjC-0002CD-9R for qemu-devel@nongnu.org; Mon, 24 Apr 2017 15:32:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d2jj8-0001eN-BG for qemu-devel@nongnu.org; Mon, 24 Apr 2017 15:32:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44242) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d2jj8-0001de-5P for qemu-devel@nongnu.org; Mon, 24 Apr 2017 15:32:50 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EDD328553E for ; Mon, 24 Apr 2017 19:32:48 +0000 (UTC) Date: Mon, 24 Apr 2017 21:32:33 +0200 From: Igor Mammedov Message-ID: <20170424213233.2d19bdab@Igors-MacBook-Pro.local> In-Reply-To: <20170424191317.GA3482@thinpad.lan.raisama.net> References: <20170424185817.41002-1-imammedo@redhat.com> <20170424191317.GA3482@thinpad.lan.raisama.net> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] pc/fwcfg: unbreak migration from qemu-2.5 and qemu-2.6 during firmware boot List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: qemu-devel@nongnu.org, pbonzini@redhat.com, mst@redhat.com, dgilbert@redhat.com, lersek@redhat.com On Mon, 24 Apr 2017 16:13:17 -0300 Eduardo Habkost wrote: > On Mon, Apr 24, 2017 at 08:58:17PM +0200, Igor Mammedov wrote: > [...] > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > > index f3b372a18f..3f2d96da64 100644 > > --- a/hw/i386/pc.c > > +++ b/hw/i386/pc.c > > @@ -1047,7 +1047,7 @@ static void load_linux(PCMachineState *pcms, > > fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, setup_size); > > fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA, setup, setup_size); > > > > - if (fw_cfg_dma_enabled(fw_cfg)) { > > + if (!pcmc->linuxboot_dma_disabled && fw_cfg_dma_enabled(fw_cfg)) { > > Why not name the flag just "linuxboot_dma", set it to true by > default at pc_machine_class_init(), and avoid the double > negative? to avoid setting it to true somewhere else, so less thing could go wrong but is you prefer *_enable variant I can switch to it. > > [...] > > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h > > index f278b3ae89..ff6f13b61b 100644 > > --- a/include/hw/i386/pc.h > > +++ b/include/hw/i386/pc.h > > @@ -151,6 +151,8 @@ struct PCMachineClass { > > bool save_tsc_khz; > > /* generate legacy CPU hotplug AML */ > > bool legacy_cpu_hotplug; > > + > > A one-line description of the consequences of setting/clearing > the flag would be nice. will fix in v2 > > > + bool linuxboot_dma_disabled; > > }; > > > > #define TYPE_PC_MACHINE "generic-pc-machine" > > @@ -432,10 +434,6 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); > > #define PC_COMPAT_2_6 \ > > HW_COMPAT_2_6 \ > > {\ > > - .driver = "fw_cfg_io",\ > > - .property = "dma_enabled",\ > > - .value = "off",\ > > - },{\ > > .driver = TYPE_X86_CPU,\ > > .property = "cpuid-0xb",\ > > .value = "off",\ > > -- > > 2.11.0 (Apple Git-81) > > >