[Qemu-devel] [PATCH] i386: Support "-cpu host" on TCG too

[Eduardo Habkost]

Change the meaning of "-cpu host" to "enable all features
supported by the accelerator in the current host", so that it can
be used to enable/query all features supported by TCG.

To make sure "host" is still at the end of the list in "-cpu
help", add a "ordering" field that will be used when sorting the
CPU model list.

Cc: Richard Henderson <address@hidden>
Signed-off-by: Eduardo Habkost <address@hidden>
---
 target/i386/cpu-qom.h |  4 ++--
 target/i386/cpu.c     | 26 +++++---------------------
 2 files changed, 7 insertions(+), 23 deletions(-)

diff --git a/target/i386/cpu-qom.h b/target/i386/cpu-qom.h
index 8cd607e9a2..75618919e3 100644
--- a/target/i386/cpu-qom.h
+++ b/target/i386/cpu-qom.h
@@ -47,7 +47,7 @@ typedef struct X86CPUDefinition X86CPUDefinition;
 /**
  * X86CPUClass:
  * @cpu_def: CPU model definition
- * @kvm_required: Whether CPU model requires KVM to be enabled.
+ * @ordering: Ordering on the "-cpu help" CPU model list.
  * @migration_safe: See CpuDefinitionInfo::migration_safe
  * @parent_realize: The parent class' realize handler.
  * @parent_reset: The parent class' reset handler.
@@ -62,7 +62,7 @@ typedef struct X86CPUClass {
     /* Should be eventually replaced by subclass-specific property defaults. */
     X86CPUDefinition *cpu_def;
 
-    bool kvm_required;
+    int ordering;
     bool migration_safe;
 
     /* Optional description of CPU model.
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index ec6eaf215c..e0ca8c0288 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1549,7 +1549,7 @@ static void host_x86_cpu_class_init(ObjectClass *oc, void 
*data)
     X86CPUClass *xcc = X86_CPU_CLASS(oc);
     uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
 
-    xcc->kvm_required = true;
+    xcc->ordering = 9; /* Show it last on "-cpu help" */
 
     host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx);
     x86_cpu_vendor_words2str(host_cpudef.vendor, ebx, edx, ecx);
@@ -1563,8 +1563,7 @@ static void host_x86_cpu_class_init(ObjectClass *oc, void 
*data)
 
     xcc->cpu_def = &host_cpudef;
     xcc->model_description =
-        "KVM processor with all supported host features "
-        "(only available in KVM mode)";
+        "Enables all features supported by the accelerator in the current 
host";
 
     /* level, xlevel, xlevel2, and the feature words are initialized on
      * instance_init, because they require KVM to be initialized.
@@ -2075,13 +2074,6 @@ static void 
x86_cpu_class_check_missing_features(X86CPUClass *xcc,
     Error *err = NULL;
     strList **next = missing_feats;
 
-    if (xcc->kvm_required && !kvm_enabled()) {
-        strList *new = g_new0(strList, 1);
-        new->value = g_strdup("kvm");;
-        *missing_feats = new;
-        return;
-    }
-
     xc = X86_CPU(object_new(object_class_get_name(OBJECT_CLASS(xcc))));
 
     x86_cpu_load_features(xc, &err);
@@ -2129,7 +2121,7 @@ static void listflags(FILE *f, fprintf_function print, 
const char **featureset)
     }
 }
 
-/* Sort alphabetically by type name, listing kvm_required models last. */
+/* Sort alphabetically by type name, respecting X86CPUClass::ordering. */
 static gint x86_cpu_list_compare(gconstpointer a, gconstpointer b)
 {
     ObjectClass *class_a = (ObjectClass *)a;
@@ -2138,9 +2130,8 @@ static gint x86_cpu_list_compare(gconstpointer a, 
gconstpointer b)
     X86CPUClass *cc_b = X86_CPU_CLASS(class_b);
     const char *name_a, *name_b;
 
-    if (cc_a->kvm_required != cc_b->kvm_required) {
-        /* kvm_required items go last */
-        return cc_a->kvm_required ? 1 : -1;
+    if (cc_a->ordering != cc_b->ordering) {
+        return cc_a->ordering - cc_b->ordering;
     } else {
         name_a = object_class_get_name(class_a);
         name_b = object_class_get_name(class_b);
@@ -3191,13 +3182,6 @@ static void x86_cpu_realizefn(DeviceState *dev, Error 
**errp)
     Error *local_err = NULL;
     static bool ht_warned;
 
-    if (xcc->kvm_required && !kvm_enabled()) {
-        char *name = x86_cpu_class_get_model_name(xcc);
-        error_setg(&local_err, "CPU model '%s' requires KVM", name);
-        g_free(name);
-        goto out;
-    }
-
     if (cpu->apic_id == UNASSIGNED_APIC_ID) {
         error_setg(errp, "apic-id property was not initialized properly");
         return;
-- 
2.11.0.259.g40922b1