[Qemu-devel] [PATCH] hw/i386: Deprecate the machine types pc-0.10 and pc-0.11

[Thomas Huth <thuth@redhat.com>]

The oldest machine type which is still used in a maintained distribution
is a pc-0.12 based machine type in RHEL6, so everything that is older
than pc-0.12 should not be used anymore. Thus let's deprecate pc-0.10
and pc-0.11 so that we can finally remove them in a future release.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 This is based on a patch that I already sent in 2017. But back then, we
 were still in progress of discussing our deprecation policies (e.g. auto-
 matic deprecation for old machine types), and there was no clear consensus
 whether we should deprecate 0.10 - 0.11, all 0.x or even up to version 1.2.
 After some iterations and too much discussion, I've forgotten about this
 patch. Anyway, I think we agreed that at least 0.10 and 0.11 can certainly
 be removed nowadays, so let's finally get at least those two machine types
 marked as deprecated! If that works fine and we will finally have removed
 these two types in v3.2, we can resume the discussion about newer machine
 types afterwards.
 
 hw/i386/pc_piix.c   | 2 ++
 include/hw/boards.h | 1 +
 qemu-doc.texi       | 5 +++++
 vl.c                | 9 +++++++--
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 3d81136..fa61dc3 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -955,6 +955,8 @@ static void pc_i440fx_0_11_machine_options(MachineClass *m)
 {
     pc_i440fx_0_12_machine_options(m);
     m->hw_version = "0.11";
+    m->deprecation_msg = "Old and unsupported machine version, "
+                         "use a newer machine type instead.";
     SET_MACHINE_COMPAT(m, PC_COMPAT_0_11);
 }
 
diff --git a/include/hw/boards.h b/include/hw/boards.h
index ef7457f..e1bd25f 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -166,6 +166,7 @@ struct MachineClass {
     char *name;
     const char *alias;
     const char *desc;
+    const char *deprecation_msg;
 
     void (*init)(MachineState *state);
     void (*reset)(void);
diff --git a/qemu-doc.texi b/qemu-doc.texi
index 2effe66..2a597d6 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -2965,6 +2965,11 @@ support page sizes < 4096 any longer.
 
 @section System emulator machines
 
+@subsection pc-0.10 and pc-0.11 (since 3.0)
+
+These machine types are very old and likely can not be used for life-migration
+from old QEMU versions anymore. A newer machine type should be used instead.
+
 @section Block device options
 
 @subsection "backing": "" (since 2.12.0)
diff --git a/vl.c b/vl.c
index 0603171..096814c 100644
--- a/vl.c
+++ b/vl.c
@@ -2560,8 +2560,9 @@ static gint machine_class_cmp(gconstpointer a, gconstpointer b)
             if (mc->alias) {
                 printf("%-20s %s (alias of %s)\n", mc->alias, mc->desc, mc->name);
             }
-            printf("%-20s %s%s\n", mc->name, mc->desc,
-                   mc->is_default ? " (default)" : "");
+            printf("%-20s %s%s%s\n", mc->name, mc->desc,
+                   mc->is_default ? " (default)" : "",
+                   mc->deprecation_msg ? " (deprecated)" : "");
         }
     }
 
@@ -3952,6 +3953,10 @@ int main(int argc, char **argv, char **envp)
     }
 
     machine_class = select_machine();
+    if (machine_class->deprecation_msg) {
+        error_report("Machine type '%s' is deprecated: %s",
+                     machine_class->name, machine_class->deprecation_msg);
+    }
 
     set_memory_options(&ram_slots, &maxram_size, machine_class);
 
-- 
1.8.3.1