[Qemu-devel] [PATCH 2/4] target-i386: Convert kvm_default_*features to property/value pairs

[Eduardo Habkost <ehabkost@redhat.com>]

Convert the kvm_default_features and kvm_default_unset_features arrays
into a simple list of property/value pairs that will be applied to
X86CPU objects when using KVM.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 hw/i386/pc_piix.c |  8 ++---
 hw/i386/pc_q35.c  |  4 +--
 target-i386/cpu.c | 87 ++++++++++++++++++++++++++++++++-----------------------
 target-i386/cpu.h | 11 +++++--
 4 files changed, 65 insertions(+), 45 deletions(-)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 3f925b2..e79ef0d 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -325,7 +325,7 @@ static void pc_compat_2_1(MachineState *machine)
 
     pc_compat_2_2(machine);
     smbios_uuid_encoded = false;
-    x86_cpu_compat_kvm_no_autodisable(FEAT_8000_0001_ECX, CPUID_EXT3_SVM);
+    x86_cpu_change_kvm_default("svm", NULL);
     pcms->enforce_aligned_dimm = false;
 }
 
@@ -361,7 +361,7 @@ static void pc_compat_1_7(MachineState *machine)
     gigabyte_align = false;
     option_rom_has_mr = true;
     legacy_acpi_table_size = 6414;
-    x86_cpu_compat_kvm_no_autoenable(FEAT_1_ECX, CPUID_EXT_X2APIC);
+    x86_cpu_change_kvm_default("x2apic", NULL);
 }
 
 static void pc_compat_1_6(MachineState *machine)
@@ -391,7 +391,7 @@ static void pc_compat_1_3(MachineState *machine)
 static void pc_compat_1_2(MachineState *machine)
 {
     pc_compat_1_3(machine);
-    x86_cpu_compat_kvm_no_autoenable(FEAT_KVM, 1 << KVM_FEATURE_PV_EOI);
+    x86_cpu_change_kvm_default("kvm-pv-eoi", NULL);
 }
 
 /* PC compat function for pc-0.10 to pc-0.13 */
@@ -414,7 +414,7 @@ static void pc_init_isa(MachineState *machine)
     if (!machine->cpu_model) {
         machine->cpu_model = "486";
     }
-    x86_cpu_compat_kvm_no_autoenable(FEAT_KVM, 1 << KVM_FEATURE_PV_EOI);
+    x86_cpu_change_kvm_default("kvm-pv-eoi", NULL);
     enable_compat_apic_id_mode();
     pc_init1(machine, TYPE_I440FX_PCI_HOST_BRIDGE, TYPE_I440FX_PCI_DEVICE);
 }
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 11601ab..c17d9df 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -309,7 +309,7 @@ static void pc_compat_2_1(MachineState *machine)
     pc_compat_2_2(machine);
     pcms->enforce_aligned_dimm = false;
     smbios_uuid_encoded = false;
-    x86_cpu_compat_kvm_no_autodisable(FEAT_8000_0001_ECX, CPUID_EXT3_SVM);
+    x86_cpu_change_kvm_default("svm", NULL);
 }
 
 static void pc_compat_2_0(MachineState *machine)
@@ -326,7 +326,7 @@ static void pc_compat_1_7(MachineState *machine)
     smbios_defaults = false;
     gigabyte_align = false;
     option_rom_has_mr = true;
-    x86_cpu_compat_kvm_no_autoenable(FEAT_1_ECX, CPUID_EXT_X2APIC);
+    x86_cpu_change_kvm_default("x2apic", NULL);
 }
 
 static void pc_compat_1_6(MachineState *machine)
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index d505743..9a4bfa3 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -478,38 +478,6 @@ const char *get_register_name_32(unsigned int reg)
     return x86_reg_info_32[reg].name;
 }
 
-/* KVM-specific features that are automatically added to all CPU models
- * when KVM is enabled.
- */
-static uint32_t kvm_default_features[FEATURE_WORDS] = {
-    [FEAT_KVM] = (1 << KVM_FEATURE_CLOCKSOURCE) |
-        (1 << KVM_FEATURE_NOP_IO_DELAY) |
-        (1 << KVM_FEATURE_CLOCKSOURCE2) |
-        (1 << KVM_FEATURE_ASYNC_PF) |
-        (1 << KVM_FEATURE_STEAL_TIME) |
-        (1 << KVM_FEATURE_PV_EOI) |
-        (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT),
-    [FEAT_1_ECX] = CPUID_EXT_X2APIC,
-};
-
-/* Features that are not added by default to any CPU model when KVM is enabled.
- */
-static uint32_t kvm_default_unset_features[FEATURE_WORDS] = {
-    [FEAT_1_EDX] = CPUID_ACPI,
-    [FEAT_1_ECX] = CPUID_EXT_MONITOR,
-    [FEAT_8000_0001_ECX] = CPUID_EXT3_SVM,
-};
-
-void x86_cpu_compat_kvm_no_autoenable(FeatureWord w, uint32_t features)
-{
-    kvm_default_features[w] &= ~features;
-}
-
-void x86_cpu_compat_kvm_no_autodisable(FeatureWord w, uint32_t features)
-{
-    kvm_default_unset_features[w] &= ~features;
-}
-
 /*
  * Returns the set of feature flags that are supported and migratable by
  * QEMU, for a given FeatureWord.
@@ -1398,6 +1366,43 @@ static X86CPUDefinition builtin_x86_defs[] = {
     },
 };
 
+typedef struct PropValue {
+    const char *prop, *value;
+} PropValue;
+
+/* KVM-specific features that are automatically added/removed
+ * from all CPU models when KVM is enabled.
+ */
+static PropValue kvm_default_props[] = {
+    { "kvmclock", "on" },
+    { "kvm-nopiodelay", "on" },
+    { "kvm-asyncpf", "on" },
+    { "kvm-steal-time", "on" },
+    { "kvm-pv-eoi", "on" },
+    { "kvmclock-stable-bit", "on" },
+    { "x2apic", "on" },
+    { "acpi", "off" },
+    { "monitor", "off" },
+    { "svm", "off" },
+    { NULL, NULL },
+};
+
+void x86_cpu_change_kvm_default(const char *prop, const char *value)
+{
+    PropValue *pv;
+    for (pv = kvm_default_props; pv->prop; pv++) {
+        if (!strcmp(pv->prop, prop)) {
+            pv->value = value;
+            break;
+        }
+    }
+
+    /* It is valid to call this function only for properties that
+     * are already present in the kvm_default_props table.
+     */
+    assert(pv->prop);
+}
+
 static uint32_t x86_cpu_get_supported_feature_word(FeatureWord w,
                                                    bool migratable_only);
 
@@ -2067,6 +2072,18 @@ static int x86_cpu_filter_features(X86CPU *cpu)
     return rv;
 }
 
+static void x86_cpu_apply_props(X86CPU *cpu, PropValue *props)
+{
+    PropValue *pv;
+    for (pv = props; pv->prop; pv++) {
+        if (!pv->value) {
+            continue;
+        }
+        object_property_parse(OBJECT(cpu), pv->value, pv->prop,
+                              &error_abort);
+    }
+}
+
 /* Load data from X86CPUDefinition
  */
 static void x86_cpu_load_def(X86CPU *cpu, X86CPUDefinition *def, Error **errp)
@@ -2090,11 +2107,7 @@ static void x86_cpu_load_def(X86CPU *cpu, X86CPUDefinition *def, Error **errp)
 
     /* Special cases not set in the X86CPUDefinition structs: */
     if (kvm_enabled()) {
-        FeatureWord w;
-        for (w = 0; w < FEATURE_WORDS; w++) {
-            env->features[w] |= kvm_default_features[w];
-            env->features[w] &= ~kvm_default_unset_features[w];
-        }
+        x86_cpu_apply_props(cpu, kvm_default_props);
     }
 
     env->features[FEAT_1_ECX] |= CPUID_EXT_HYPERVISOR;
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 74b674d..f7c733b 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -1332,8 +1332,15 @@ void cpu_smm_update(X86CPU *cpu);
 
 void cpu_report_tpr_access(CPUX86State *env, TPRAccess access);
 
-void x86_cpu_compat_kvm_no_autoenable(FeatureWord w, uint32_t features);
-void x86_cpu_compat_kvm_no_autodisable(FeatureWord w, uint32_t features);
+/* Change the value of a KVM-specific default
+ *
+ * If value is NULL, no default will be set and the original
+ * value from the CPU model table will be kept.
+ *
+ * It is valid to call this funciton only for properties that
+ * are already present in the kvm_default_props table.
+ */
+void x86_cpu_change_kvm_default(const char *prop, const char *value);
 
 
 /* Return name of 32-bit register, from a R_* constant */
-- 
2.1.0