From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42046) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YPsZB-0000pa-MF for qemu-devel@nongnu.org; Mon, 23 Feb 2015 07:56:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YPsZ4-0007io-2m for qemu-devel@nongnu.org; Mon, 23 Feb 2015 07:56:53 -0500 Received: from cantor2.suse.de ([195.135.220.15]:47039 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YPsZ3-0007iK-SQ for qemu-devel@nongnu.org; Mon, 23 Feb 2015 07:56:46 -0500 From: Alexander Graf Date: Mon, 23 Feb 2015 13:56:43 +0100 Message-Id: <1424696203-76895-4-git-send-email-agraf@suse.de> In-Reply-To: <1424696203-76895-1-git-send-email-agraf@suse.de> References: <1424696203-76895-1-git-send-email-agraf@suse.de> Subject: [Qemu-devel] [PATCH v2 3/3] pc: Disable vmdesc submission for old machines List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: lmr@redhat.com, amit.shah@redhat.com, dgilbert@redhat.com, quintela@redhat.com Older PC machine types might by accident be backwards live migration compatible, but with the new vmdesc self-describing blob in our live migration stream we would break that compatibility. Also users wouldn't expect massive behaviorial differences when updating to a new version of QEMU while retaining their old machine type, especially not potential breakage in tooling around live migration. So disable vmdesc submission for old PC machine types. Signed-off-by: Alexander Graf --- hw/i386/pc_piix.c | 1 + hw/i386/pc_q35.c | 1 + 2 files changed, 2 insertions(+) diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index 38b42b0..35bc377 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -332,6 +332,7 @@ static void pc_compat_2_2(MachineState *machine) CPUID_7_0_EBX_HLE | CPUID_7_0_EBX_RTM, 0); x86_cpu_compat_set_features("Broadwell", FEAT_7_0_EBX, CPUID_7_0_EBX_HLE | CPUID_7_0_EBX_RTM, 0); + machine->suppress_vmdesc = true; } static void pc_compat_2_1(MachineState *machine) diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index 63027ee..1305eb0 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -311,6 +311,7 @@ static void pc_compat_2_2(MachineState *machine) CPUID_7_0_EBX_HLE | CPUID_7_0_EBX_RTM, 0); x86_cpu_compat_set_features("Broadwell", FEAT_7_0_EBX, CPUID_7_0_EBX_HLE | CPUID_7_0_EBX_RTM, 0); + machine->suppress_vmdesc = true; } static void pc_compat_2_1(MachineState *machine) -- 1.7.12.4