pc: Disable vmdesc submission for old machines

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 <agraf@suse.de> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Juan Quintela <quintela@redhat.com>
cHolzberger · Mar 16, 2015 · 54ed388 · 54ed388
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commit 54ed388
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diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
@@ -335,6 +335,7 @@ 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
@@ -314,6 +314,7 @@ 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)