[Qemu-devel] [PATCH] target/ppc: Avoid printing wrong aliases in CPU help text

[Qemu-devel] [PATCH] target/ppc: Avoid printing wrong aliases in CPU help text

[Thomas Huth]

When running with KVM, we update the "family" CPU alias to point
to the right host CPU type, so that it is for example possible to
use "-cpu POWER8" on a POWER8NVL host. However, the function for
printing the list of available CPU models is called earlier than
the KVM setup code, so the output of "-cpu help" is wrong in that
case. Since it would be somewhat ugly anyway to have different
help texts depending on whether "-enable-kvm" has been specified
or not, we should better always print the same text, so fix this
issue by printing "alias for preferred XXX CPU" instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 target/ppc/cpu.h            |  1 +
 target/ppc/kvm.c            | 12 ------------
 target/ppc/translate_init.c | 27 +++++++++++++++++++++++++--
 3 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index 7c4a1f5..21752ff 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1216,6 +1216,7 @@ static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState *env)
 
 PowerPCCPUClass *ppc_cpu_class_by_pvr(uint32_t pvr);
 PowerPCCPUClass *ppc_cpu_class_by_pvr_mask(uint32_t pvr);
+PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc);
 
 struct PPCVirtualHypervisor {
     Object parent;
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 9f1f132..585e6d3 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -2304,18 +2304,6 @@ bool kvmppc_has_cap_htm(void)
     return cap_htm;
 }
 
-static PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
-{
-    ObjectClass *oc = OBJECT_CLASS(pcc);
-
-    while (oc && !object_class_is_abstract(oc)) {
-        oc = object_class_get_parent(oc);
-    }
-    assert(oc);
-
-    return POWERPC_CPU_CLASS(oc);
-}
-
 PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void)
 {
     uint32_t host_pvr = mfpvr();
diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
index c1a9014..9e9c37f 100644
--- a/target/ppc/translate_init.c
+++ b/target/ppc/translate_init.c
@@ -10249,6 +10249,18 @@ PowerPCCPU *cpu_ppc_init(const char *cpu_model)
     return POWERPC_CPU(cpu_generic_init(TYPE_POWERPC_CPU, cpu_model));
 }
 
+PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
+{
+    ObjectClass *oc = OBJECT_CLASS(pcc);
+
+    while (oc && !object_class_is_abstract(oc)) {
+        oc = object_class_get_parent(oc);
+    }
+    assert(oc);
+
+    return POWERPC_CPU_CLASS(oc);
+}
+
 /* Sort by PVR, ordering special case "host" last. */
 static gint ppc_cpu_list_compare(gconstpointer a, gconstpointer b)
 {
@@ -10280,6 +10292,7 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
     ObjectClass *oc = data;
     CPUListState *s = user_data;
     PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
+    DeviceClass *family = DEVICE_CLASS(ppc_cpu_get_family_class(pcc));
     const char *typename = object_class_get_name(oc);
     char *name;
     int i;
@@ -10302,8 +10315,18 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
         if (alias_oc != oc) {
             continue;
         }
-        (*s->cpu_fprintf)(s->file, "PowerPC %-16s (alias for %s)\n",
-                          alias->alias, name);
+        /*
+         * If running with KVM, we might update the family alias later, so
+         * avoid printing the wrong alias here and use "preferred" instead
+         */
+        if (strcmp(alias->alias, family->desc) == 0) {
+            (*s->cpu_fprintf)(s->file,
+                              "PowerPC %-16s (alias for preferred %s CPU)\n",
+                              alias->alias, family->desc);
+        } else {
+            (*s->cpu_fprintf)(s->file, "PowerPC %-16s (alias for %s)\n",
+                              alias->alias, name);
+        }
     }
     g_free(name);
 }
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH] target/ppc: Avoid printing wrong aliases in CPU help text

[Eduardo Habkost]

On Wed, Mar 08, 2017 at 08:05:36PM +0100, Thomas Huth wrote:
> When running with KVM, we update the "family" CPU alias to point
> to the right host CPU type, so that it is for example possible to
> use "-cpu POWER8" on a POWER8NVL host. However, the function for
> printing the list of available CPU models is called earlier than
> the KVM setup code, so the output of "-cpu help" is wrong in that
> case. Since it would be somewhat ugly anyway to have different
> help texts depending on whether "-enable-kvm" has been specified
> or not, we should better always print the same text, so fix this
> issue by printing "alias for preferred XXX CPU" instead.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

But I wonder if it wouldn't be safer and easier to follow if we
just added a bool field to PowerPCCPUAlias to indicate which
aliases are not accel-independent. When I looked at
ppc_cpu_aliases[] the first time, I had no idea the table was not
100% static and would be changed by KVM code.

> ---
>  target/ppc/cpu.h            |  1 +
>  target/ppc/kvm.c            | 12 ------------
>  target/ppc/translate_init.c | 27 +++++++++++++++++++++++++--
>  3 files changed, 26 insertions(+), 14 deletions(-)
> 
> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> index 7c4a1f5..21752ff 100644
> --- a/target/ppc/cpu.h
> +++ b/target/ppc/cpu.h
> @@ -1216,6 +1216,7 @@ static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState *env)
>  
>  PowerPCCPUClass *ppc_cpu_class_by_pvr(uint32_t pvr);
>  PowerPCCPUClass *ppc_cpu_class_by_pvr_mask(uint32_t pvr);
> +PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc);
>  
>  struct PPCVirtualHypervisor {
>      Object parent;
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 9f1f132..585e6d3 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -2304,18 +2304,6 @@ bool kvmppc_has_cap_htm(void)
>      return cap_htm;
>  }
>  
> -static PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
> -{
> -    ObjectClass *oc = OBJECT_CLASS(pcc);
> -
> -    while (oc && !object_class_is_abstract(oc)) {
> -        oc = object_class_get_parent(oc);
> -    }
> -    assert(oc);
> -
> -    return POWERPC_CPU_CLASS(oc);
> -}
> -
>  PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void)
>  {
>      uint32_t host_pvr = mfpvr();
> diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
> index c1a9014..9e9c37f 100644
> --- a/target/ppc/translate_init.c
> +++ b/target/ppc/translate_init.c
> @@ -10249,6 +10249,18 @@ PowerPCCPU *cpu_ppc_init(const char *cpu_model)
>      return POWERPC_CPU(cpu_generic_init(TYPE_POWERPC_CPU, cpu_model));
>  }
>  
> +PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
> +{
> +    ObjectClass *oc = OBJECT_CLASS(pcc);
> +
> +    while (oc && !object_class_is_abstract(oc)) {
> +        oc = object_class_get_parent(oc);
> +    }
> +    assert(oc);
> +
> +    return POWERPC_CPU_CLASS(oc);
> +}
> +
>  /* Sort by PVR, ordering special case "host" last. */
>  static gint ppc_cpu_list_compare(gconstpointer a, gconstpointer b)
>  {
> @@ -10280,6 +10292,7 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
>      ObjectClass *oc = data;
>      CPUListState *s = user_data;
>      PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> +    DeviceClass *family = DEVICE_CLASS(ppc_cpu_get_family_class(pcc));
>      const char *typename = object_class_get_name(oc);
>      char *name;
>      int i;
> @@ -10302,8 +10315,18 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
>          if (alias_oc != oc) {
>              continue;
>          }
> -        (*s->cpu_fprintf)(s->file, "PowerPC %-16s (alias for %s)\n",
> -                          alias->alias, name);
> +        /*
> +         * If running with KVM, we might update the family alias later, so
> +         * avoid printing the wrong alias here and use "preferred" instead
> +         */
> +        if (strcmp(alias->alias, family->desc) == 0) {
> +            (*s->cpu_fprintf)(s->file,
> +                              "PowerPC %-16s (alias for preferred %s CPU)\n",
> +                              alias->alias, family->desc);
> +        } else {
> +            (*s->cpu_fprintf)(s->file, "PowerPC %-16s (alias for %s)\n",
> +                              alias->alias, name);
> +        }
>      }
>      g_free(name);
>  }
> -- 
> 1.8.3.1
> 

-- 
Eduardo

Re: [Qemu-devel] [Qemu-ppc] [PATCH] target/ppc: Avoid printing wrong aliases in CPU help text

[Thomas Huth]

On 08.03.2017 20:05, Thomas Huth wrote:
> When running with KVM, we update the "family" CPU alias to point
> to the right host CPU type, so that it is for example possible to
> use "-cpu POWER8" on a POWER8NVL host. However, the function for
> printing the list of available CPU models is called earlier than
> the KVM setup code, so the output of "-cpu help" is wrong in that
> case. Since it would be somewhat ugly anyway to have different
> help texts depending on whether "-enable-kvm" has been specified
> or not, we should better always print the same text, so fix this
> issue by printing "alias for preferred XXX CPU" instead.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  target/ppc/cpu.h            |  1 +
>  target/ppc/kvm.c            | 12 ------------
>  target/ppc/translate_init.c | 27 +++++++++++++++++++++++++--
>  3 files changed, 26 insertions(+), 14 deletions(-)
> 
> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> index 7c4a1f5..21752ff 100644
> --- a/target/ppc/cpu.h
> +++ b/target/ppc/cpu.h
> @@ -1216,6 +1216,7 @@ static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState *env)
>  
>  PowerPCCPUClass *ppc_cpu_class_by_pvr(uint32_t pvr);
>  PowerPCCPUClass *ppc_cpu_class_by_pvr_mask(uint32_t pvr);
> +PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc);
>  
>  struct PPCVirtualHypervisor {
>      Object parent;
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 9f1f132..585e6d3 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -2304,18 +2304,6 @@ bool kvmppc_has_cap_htm(void)
>      return cap_htm;
>  }
>  
> -static PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
> -{
> -    ObjectClass *oc = OBJECT_CLASS(pcc);
> -
> -    while (oc && !object_class_is_abstract(oc)) {
> -        oc = object_class_get_parent(oc);
> -    }
> -    assert(oc);
> -
> -    return POWERPC_CPU_CLASS(oc);
> -}
> -
>  PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void)
>  {
>      uint32_t host_pvr = mfpvr();
> diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
> index c1a9014..9e9c37f 100644
> --- a/target/ppc/translate_init.c
> +++ b/target/ppc/translate_init.c
> @@ -10249,6 +10249,18 @@ PowerPCCPU *cpu_ppc_init(const char *cpu_model)
>      return POWERPC_CPU(cpu_generic_init(TYPE_POWERPC_CPU, cpu_model));
>  }
>  
> +PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
> +{
> +    ObjectClass *oc = OBJECT_CLASS(pcc);
> +
> +    while (oc && !object_class_is_abstract(oc)) {
> +        oc = object_class_get_parent(oc);
> +    }
> +    assert(oc);
> +
> +    return POWERPC_CPU_CLASS(oc);
> +}
> +
>  /* Sort by PVR, ordering special case "host" last. */
>  static gint ppc_cpu_list_compare(gconstpointer a, gconstpointer b)
>  {
> @@ -10280,6 +10292,7 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
>      ObjectClass *oc = data;
>      CPUListState *s = user_data;
>      PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> +    DeviceClass *family = DEVICE_CLASS(ppc_cpu_get_family_class(pcc));
>      const char *typename = object_class_get_name(oc);
>      char *name;
>      int i;
> @@ -10302,8 +10315,18 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
>          if (alias_oc != oc) {
>              continue;
>          }
> -        (*s->cpu_fprintf)(s->file, "PowerPC %-16s (alias for %s)\n",
> -                          alias->alias, name);
> +        /*
> +         * If running with KVM, we might update the family alias later, so
> +         * avoid printing the wrong alias here and use "preferred" instead
> +         */
> +        if (strcmp(alias->alias, family->desc) == 0) {
> +            (*s->cpu_fprintf)(s->file,
> +                              "PowerPC %-16s (alias for preferred %s CPU)\n",
> +                              alias->alias, family->desc);
> +        } else {
> +            (*s->cpu_fprintf)(s->file, "PowerPC %-16s (alias for %s)\n",
> +                              alias->alias, name);
> +        }
>      }
>      g_free(name);
>  }
> 

Ping!

... I think this got somehow lost in the 2.9 rush ...

 Thomas

Re: [Qemu-devel] [Qemu-ppc] [PATCH] target/ppc: Avoid printing wrong aliases in CPU help text

[David Gibson]

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On Tue, May 09, 2017 at 06:49:29AM +0200, Thomas Huth wrote:
> On 08.03.2017 20:05, Thomas Huth wrote:
> > When running with KVM, we update the "family" CPU alias to point
> > to the right host CPU type, so that it is for example possible to
> > use "-cpu POWER8" on a POWER8NVL host. However, the function for
> > printing the list of available CPU models is called earlier than
> > the KVM setup code, so the output of "-cpu help" is wrong in that
> > case. Since it would be somewhat ugly anyway to have different
> > help texts depending on whether "-enable-kvm" has been specified
> > or not, we should better always print the same text, so fix this
> > issue by printing "alias for preferred XXX CPU" instead.
> > 
> > Signed-off-by: Thomas Huth <thuth@redhat.com>
> > ---
> >  target/ppc/cpu.h            |  1 +
> >  target/ppc/kvm.c            | 12 ------------
> >  target/ppc/translate_init.c | 27 +++++++++++++++++++++++++--
> >  3 files changed, 26 insertions(+), 14 deletions(-)
> > 
> > diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> > index 7c4a1f5..21752ff 100644
> > --- a/target/ppc/cpu.h
> > +++ b/target/ppc/cpu.h
> > @@ -1216,6 +1216,7 @@ static inline PowerPCCPU *ppc_env_get_cpu(CPUPPCState *env)
> >  
> >  PowerPCCPUClass *ppc_cpu_class_by_pvr(uint32_t pvr);
> >  PowerPCCPUClass *ppc_cpu_class_by_pvr_mask(uint32_t pvr);
> > +PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc);
> >  
> >  struct PPCVirtualHypervisor {
> >      Object parent;
> > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> > index 9f1f132..585e6d3 100644
> > --- a/target/ppc/kvm.c
> > +++ b/target/ppc/kvm.c
> > @@ -2304,18 +2304,6 @@ bool kvmppc_has_cap_htm(void)
> >      return cap_htm;
> >  }
> >  
> > -static PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
> > -{
> > -    ObjectClass *oc = OBJECT_CLASS(pcc);
> > -
> > -    while (oc && !object_class_is_abstract(oc)) {
> > -        oc = object_class_get_parent(oc);
> > -    }
> > -    assert(oc);
> > -
> > -    return POWERPC_CPU_CLASS(oc);
> > -}
> > -
> >  PowerPCCPUClass *kvm_ppc_get_host_cpu_class(void)
> >  {
> >      uint32_t host_pvr = mfpvr();
> > diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
> > index c1a9014..9e9c37f 100644
> > --- a/target/ppc/translate_init.c
> > +++ b/target/ppc/translate_init.c
> > @@ -10249,6 +10249,18 @@ PowerPCCPU *cpu_ppc_init(const char *cpu_model)
> >      return POWERPC_CPU(cpu_generic_init(TYPE_POWERPC_CPU, cpu_model));
> >  }
> >  
> > +PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
> > +{
> > +    ObjectClass *oc = OBJECT_CLASS(pcc);
> > +
> > +    while (oc && !object_class_is_abstract(oc)) {
> > +        oc = object_class_get_parent(oc);
> > +    }
> > +    assert(oc);
> > +
> > +    return POWERPC_CPU_CLASS(oc);
> > +}
> > +
> >  /* Sort by PVR, ordering special case "host" last. */
> >  static gint ppc_cpu_list_compare(gconstpointer a, gconstpointer b)
> >  {
> > @@ -10280,6 +10292,7 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
> >      ObjectClass *oc = data;
> >      CPUListState *s = user_data;
> >      PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
> > +    DeviceClass *family = DEVICE_CLASS(ppc_cpu_get_family_class(pcc));
> >      const char *typename = object_class_get_name(oc);
> >      char *name;
> >      int i;
> > @@ -10302,8 +10315,18 @@ static void ppc_cpu_list_entry(gpointer data, gpointer user_data)
> >          if (alias_oc != oc) {
> >              continue;
> >          }
> > -        (*s->cpu_fprintf)(s->file, "PowerPC %-16s (alias for %s)\n",
> > -                          alias->alias, name);
> > +        /*
> > +         * If running with KVM, we might update the family alias later, so
> > +         * avoid printing the wrong alias here and use "preferred" instead
> > +         */
> > +        if (strcmp(alias->alias, family->desc) == 0) {
> > +            (*s->cpu_fprintf)(s->file,
> > +                              "PowerPC %-16s (alias for preferred %s CPU)\n",
> > +                              alias->alias, family->desc);
> > +        } else {
> > +            (*s->cpu_fprintf)(s->file, "PowerPC %-16s (alias for %s)\n",
> > +                              alias->alias, name);
> > +        }
> >      }
> >      g_free(name);
> >  }
> > 
> 
> Ping!
> 
> ... I think this got somehow lost in the 2.9 rush ...

Yes, I think so.  Can you make sure it's rebased and repost, please.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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