[2/4] hw/s390x: Remove the obsolete hpage_1m_allowed switch

Commit Message

Thomas Huth April 14, 2025, 1:29 p.m. UTC

From: Thomas Huth <[e-mail]>

The s390-ccw-virtio-3.0 machine was the last one that used the
hpage_1m_allowed switch. Since we removed this machine type, we
can now remove the switch and the related code, too. This allows
us to get rid of the get_machine_class() hack and the big fat
warning comment there.

Signed-off-by: Thomas Huth <[e-mail]>
---
 include/hw/s390x/s390-virtio-ccw.h |  4 ----
 hw/s390x/s390-virtio-ccw.c         | 35 ------------------------------
 target/s390x/kvm/kvm.c             |  6 -----
 3 files changed, 45 deletions(-)

Comments

Philippe Mathieu-Daudé April 14, 2025, 4:20 p.m. UTC | #1

On 14/4/25 15:29, Thomas Huth wrote:
> From: Thomas Huth <[e-mail]>
> 
> The s390-ccw-virtio-3.0 machine was the last one that used the
> hpage_1m_allowed switch. Since we removed this machine type, we
> can now remove the switch and the related code, too. This allows
> us to get rid of the get_machine_class() hack and the big fat
> warning comment there.
> 
> Signed-off-by: Thomas Huth <[e-mail]>
> ---
>   include/hw/s390x/s390-virtio-ccw.h |  4 ----
>   hw/s390x/s390-virtio-ccw.c         | 35 ------------------------------
>   target/s390x/kvm/kvm.c             |  6 -----
>   3 files changed, 45 deletions(-)

> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index 370b03a0b97..a4fe1e47150 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -746,39 +746,6 @@ static inline void machine_set_dea_key_wrap(Object *obj, bool value,
>       ms->dea_key_wrap = value;
>   }
>   
> -static S390CcwMachineClass *current_mc;

Wow, good cleanup.

> @@ -883,7 +849,6 @@ static const TypeInfo ccw_machine_info = {
>   #define DEFINE_CCW_MACHINE_IMPL(latest, ...)                                  \
>       static void MACHINE_VER_SYM(mach_init, ccw, __VA_ARGS__)(MachineState *mach) \
>       {                                                                         \
> -        current_mc = S390_CCW_MACHINE_CLASS(MACHINE_GET_CLASS(mach));         \
>           MACHINE_VER_SYM(instance_options, ccw, __VA_ARGS__)(mach);            \
>           ccw_init(mach);                                                       \
>       }                                                                         \

Reviewed-by: Philippe Mathieu-Daudé <[e-mail]>

Patch

diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
index 686d9497d20..321b26df308 100644
--- a/include/hw/s390x/s390-virtio-ccw.h
+++ b/include/hw/s390x/s390-virtio-ccw.h
@@ -53,11 +53,7 @@  struct S390CcwMachineClass {
     MachineClass parent_class;
 
     /*< public >*/
-    bool hpage_1m_allowed;
     int max_threads;
 };
 
-/* 1M huge page mappings allowed by the machine */
-bool hpage_1m_allowed(void);
-
 #endif
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 370b03a0b97..a4fe1e47150 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -746,39 +746,6 @@  static inline void machine_set_dea_key_wrap(Object *obj, bool value,
     ms->dea_key_wrap = value;
 }
 
-static S390CcwMachineClass *current_mc;
-
-/*
- * Get the class of the s390-ccw-virtio machine that is currently in use.
- * Note: libvirt is using the "none" machine to probe for the features of the
- * host CPU, so in case this is called with the "none" machine, the function
- * returns the TYPE_S390_CCW_MACHINE base class. In this base class, all the
- * various "*_allowed" variables are enabled, so that the *_allowed() wrappers
- * below return the correct default value for the "none" machine.
- *
- * Attention! Do *not* add additional new wrappers for CPU features via this
- * mechanism anymore. CPU features should be handled via the CPU models,
- * i.e. checking with s390_has_feat() should be sufficient.
- */
-static S390CcwMachineClass *get_machine_class(void)
-{
-    if (unlikely(!current_mc)) {
-        /*
-        * No s390 ccw machine was instantiated, we are likely to
-        * be called for the 'none' machine. The properties will
-        * have their after-initialization values.
-        */
-        current_mc = S390_CCW_MACHINE_CLASS(
-                     object_class_by_name(TYPE_S390_CCW_MACHINE));
-    }
-    return current_mc;
-}
-
-bool hpage_1m_allowed(void)
-{
-    return get_machine_class()->hpage_1m_allowed;
-}
-
 static void machine_get_loadparm(Object *obj, Visitor *v,
                                  const char *name, void *opaque,
                                  Error **errp)
@@ -811,7 +778,6 @@  static void ccw_machine_class_init(ObjectClass *oc, void *data)
     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
     S390CcwMachineClass *s390mc = S390_CCW_MACHINE_CLASS(mc);
 
-    s390mc->hpage_1m_allowed = true;
     s390mc->max_threads = 1;
     mc->reset = s390_machine_reset;
     mc->block_default_type = IF_VIRTIO;
@@ -883,7 +849,6 @@  static const TypeInfo ccw_machine_info = {
 #define DEFINE_CCW_MACHINE_IMPL(latest, ...)                                  \
     static void MACHINE_VER_SYM(mach_init, ccw, __VA_ARGS__)(MachineState *mach) \
     {                                                                         \
-        current_mc = S390_CCW_MACHINE_CLASS(MACHINE_GET_CLASS(mach));         \
         MACHINE_VER_SYM(instance_options, ccw, __VA_ARGS__)(mach);            \
         ccw_init(mach);                                                       \
     }                                                                         \
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index 4d56e653ddf..fb14d2b182f 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -298,12 +298,6 @@  void kvm_s390_set_max_pagesize(uint64_t pagesize, Error **errp)
         return;
     }
 
-    if (!hpage_1m_allowed()) {
-        error_setg(errp, "This QEMU machine does not support huge page "
-                   "mappings");
-        return;
-    }
-
     if (pagesize != 1 * MiB) {
         error_setg(errp, "Memory backing with 2G pages was specified, "
                    "but KVM does not support this memory backing");