From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52175) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UjlOK-0005fp-64 for qemu-devel@nongnu.org; Tue, 04 Jun 2013 03:10:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UjlC9-0001e2-9r for qemu-devel@nongnu.org; Tue, 04 Jun 2013 02:58:15 -0400 Received: from mail-wi0-x22e.google.com ([2a00:1450:400c:c05::22e]:61398) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ujl1L-0005uj-Ue for qemu-devel@nongnu.org; Tue, 04 Jun 2013 02:47:04 -0400 Received: by mail-wi0-f174.google.com with SMTP id c10so3419577wiw.7 for ; Mon, 03 Jun 2013 23:47:03 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <51AD8D5A.6050709@redhat.com> Date: Tue, 04 Jun 2013 08:46:50 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1370272748-10629-1-git-send-email-pbonzini@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/3] Remove legacy sysfw code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jordan Justen Cc: Jordan Justen , qemu-devel , Markus Armbruster Il 03/06/2013 23:56, Jordan Justen ha scritto: > You seem to have a much better handle than I do on machine migration > and backward compatibility issues within QEMU. > > One difference we'll see from this series is that... > > With QEMU 1.2, an error would always be generated with: > qemu-system-x86_64 -M pc-1.2 -enable-kvm -pflash flash.bin > > Whereas in QEMU 1.6 the same command may succeed if the kernel > supports the READONLY kvm feature. > > Will one other result of this series be that basically any of the > older pc machines can now use -pflash? Yes, that's it and it's fine (it's a new feature, it doesn't matter). Similarly, qemu-system-x86_64 -M pc-1.0 -pflash flash.bin will create flash while it would have failed in real QEMU 1.0. The main difference is that with QEMU 1.2 this will use read-only flash: qemu-system-x86_64 -M pc-1.2 whereas in QEMU 1.6 the same command will always use BIOS, as has always been the case with qemu-system-x86_64 -M pc-1.2 --enable-kvm These semantics are much simpler to use and explain, and probably should have been like that all the time. Paolo > Anyway, that doesn't seem like a big issue to me, so for the series: > Reviewed-by: Jordan Justen > > -Jordan > > On Mon, Jun 3, 2013 at 8:19 AM, Paolo Bonzini wrote: >> The sysfw code to choose between ROM and flash BIOS was a bad idea, >> because it triggered different behavior between TCG and KVM. We >> deleted the behavior in 1.5, but we left the code around because >> it was close to the release. Now it's time to delete it. >> >> Paolo Bonzini (3): >> remove read-only pc_sysfw_flash_vs_rom_bug_compatible >> pc_sysfw: remove the rom_only property >> pc_sysfw: do not make it a device anymore >> >> default-configs/i386-softmmu.mak | 1 - >> default-configs/x86_64-softmmu.mak | 1 - >> hw/block/Makefile.objs | 1 - >> hw/i386/Makefile.objs | 1 + >> hw/i386/pc.c | 5 +- >> hw/i386/pc_piix.c | 16 +---- >> hw/i386/pc_q35.c | 2 +- >> hw/{block => i386}/pc_sysfw.c | 135 +++---------------------------------- >> include/hw/i386/pc.h | 6 +- >> 9 files changed, 18 insertions(+), 150 deletions(-) >> rename hw/{block => i386}/pc_sysfw.c (62%) >> >> -- >> 1.8.1.4 >> >> > >