hw: Nuke hw_compat_4_0_1 and pc_compat_4_0_1

Commit c87759ce876a fixed a regression affecting pc-q35 machines by
introducing a new pc-q35-4.0.1 machine version to be used instead
of pc-q35-4.0. The only purpose was to revert the default behaviour
of not using split irqchip, but the change also introduced the usual
hw_compat and pc_compat bits, and wired them for pc-q35 only.

This raises questions when it comes to add new compat properties for
4.0* machine versions of any architecture. Where to add them ? In
4.0, 4.0.1 or both ? Error prone. Another possibility would be to teach
all other architectures about 4.0.1. This solution isn't satisfying,
especially since this is a pc-q35 specific issue.

It turns out that the split irqchip default is handled in the machine
option function and doesn't involve compat lists at all.

Drop all the 4.0.1 compat lists and use the 4.0 ones instead in the 4.0.1
machine option function.

Move the compat props that were added to the 4.0.1 since c87759ce876a to
4.0.

Even if only hw_compat_4_0_1 had an impact on other architectures,
drop pc_compat_4_0_1 as well for consistency.

Fixes: c87759ce876a "q35: Revert to kernel irqchip"
Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <156051774276.244890.8660277280145466396.stgit@bahia.lan>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

3 files changed, 9 insertions, 11 deletions

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 84ebb8d..ea5a01a 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -24,16 +24,13 @@
 #include "hw/pci/pci.h"
 #include "hw/mem/nvdimm.h"
 
-GlobalProperty hw_compat_4_0_1[] = {
+GlobalProperty hw_compat_4_0[] = {
     { "VGA",            "edid", "false" },
     { "secondary-vga",  "edid", "false" },
     { "bochs-display",  "edid", "false" },
     { "virtio-vga",     "edid", "false" },
     { "virtio-gpu-pci", "edid", "false" },
 };
-const size_t hw_compat_4_0_1_len = G_N_ELEMENTS(hw_compat_4_0_1);
-
-GlobalProperty hw_compat_4_0[] = {};
 const size_t hw_compat_4_0_len = G_N_ELEMENTS(hw_compat_4_0);
 
 GlobalProperty hw_compat_3_1[] = {
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index e41192b..e96360b 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -111,9 +111,6 @@ struct hpet_fw_config hpet_cfg = {.count = UINT8_MAX};
 /* Physical Address of PVH entry point read from kernel ELF NOTE */
 static size_t pvh_start_addr;
 
-GlobalProperty pc_compat_4_0_1[] = {};
-const size_t pc_compat_4_0_1_len = G_N_ELEMENTS(pc_compat_4_0_1);
-
 GlobalProperty pc_compat_4_0[] = {};
 const size_t pc_compat_4_0_len = G_N_ELEMENTS(pc_compat_4_0);
 
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index dcddc64..57232ae 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -378,8 +378,13 @@ static void pc_q35_4_0_1_machine_options(MachineClass *m)
 {
     pc_q35_4_1_machine_options(m);
     m->alias = NULL;
-    compat_props_add(m->compat_props, hw_compat_4_0_1, hw_compat_4_0_1_len);
-    compat_props_add(m->compat_props, pc_compat_4_0_1, pc_compat_4_0_1_len);
+    /*
+     * This is the default machine for the 4.0-stable branch. It is basically
+     * a 4.0 that doesn't use split irqchip by default. It MUST hence apply the
+     * 4.0 compat props.
+     */
+    compat_props_add(m->compat_props, hw_compat_4_0, hw_compat_4_0_len);
+    compat_props_add(m->compat_props, pc_compat_4_0, pc_compat_4_0_len);
 }
 
 DEFINE_Q35_MACHINE(v4_0_1, "pc-q35-4.0.1", NULL,
@@ -390,8 +395,7 @@ static void pc_q35_4_0_machine_options(MachineClass *m)
     pc_q35_4_0_1_machine_options(m);
     m->default_kernel_irqchip_split = true;
     m->alias = NULL;
-    compat_props_add(m->compat_props, hw_compat_4_0, hw_compat_4_0_len);
-    compat_props_add(m->compat_props, pc_compat_4_0, pc_compat_4_0_len);
+    /* Compat props are applied by the 4.0.1 machine */
 }
 
 DEFINE_Q35_MACHINE(v4_0, "pc-q35-4.0", NULL,