target-i386: move cpu halted decision into x86_cpu_reset

MP initialization protocol differs between cpu families, and for P6 and
onward models it is up to CPU to decide if it will be BSP using this
protocol, so try to model this. However there is no point in implementing
MP initialization protocol in qemu. Thus first CPU is always marked as BSP.

This patch:
 - moves decision to designate BSP from board into cpu, making cpu
self-sufficient in this regard. Later it will allow to cleanup hw/pc.c
and remove cpu_reset and wrappers from there.
 - stores flag that CPU is BSP in IA32_APIC_BASE to model behavior
described in Inted SDM vol 3a part 1 chapter 8.4.1
 - uses MSR_IA32_APICBASE_BSP flag in apic_base for checking if cpu is BSP

patch is based on Jan Kiszka's proposal:
    http://thread.gmane.org/gmane.comp.emulators.qemu/100806

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

diff --git a/hw/apic.h b/hw/apic.h
index a89542b..1d48e02 100644 (file)
--- a/hw/apic.h
+++ b/hw/apic.h
@@ -21,9 +21,12 @@ void apic_sipi(DeviceState *s);
 void apic_handle_tpr_access_report(DeviceState *d, target_ulong ip,
                                    TPRAccess access);
 void apic_poll_irq(DeviceState *d);
+void apic_designate_bsp(DeviceState *d);
 
 /* pc.c */
-int cpu_is_bsp(CPUX86State *env);
 DeviceState *cpu_get_current_apic(void);
 
+/* cpu.c */
+bool cpu_is_bsp(X86CPU *cpu);
+
 #endif

diff --git a/hw/apic_common.c b/hw/apic_common.c
index 60b8259..58e63b0 100644 (file)
--- a/hw/apic_common.c
+++ b/hw/apic_common.c
@@ -43,8 +43,8 @@ uint64_t cpu_get_apic_base(DeviceState *d)
         trace_cpu_get_apic_base((uint64_t)s->apicbase);
         return s->apicbase;
     } else {
-        trace_cpu_get_apic_base(0);
-        return 0;
+        trace_cpu_get_apic_base(MSR_IA32_APICBASE_BSP);
+        return MSR_IA32_APICBASE_BSP;
     }
 }
 
@@ -201,13 +201,23 @@ void apic_init_reset(DeviceState *d)
     s->timer_expiry = -1;
 }
 
+void apic_designate_bsp(DeviceState *d)
+{
+    if (d == NULL) {
+        return;
+    }
+
+    APICCommonState *s = APIC_COMMON(d);
+    s->apicbase |= MSR_IA32_APICBASE_BSP;
+}
+
 static void apic_reset_common(DeviceState *d)
 {
     APICCommonState *s = DO_UPCAST(APICCommonState, busdev.qdev, d);
     APICCommonClass *info = APIC_COMMON_GET_CLASS(s);
     bool bsp;
 
-    bsp = cpu_is_bsp(s->cpu_env);
+    bsp = cpu_is_bsp(x86_env_get_cpu(s->cpu_env));
     s->apicbase = 0xfee00000 |
         (bsp ? MSR_IA32_APICBASE_BSP : 0) | MSR_IA32_APICBASE_ENABLE;
 

diff --git a/hw/pc.c b/hw/pc.c
index 598267a..a920686 100644 (file)
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -857,12 +857,6 @@ void pc_init_ne2k_isa(ISABus *bus, NICInfo *nd)
     nb_ne2k++;
 }
 
-int cpu_is_bsp(CPUX86State *env)
-{
-    /* We hard-wire the BSP to the first CPU. */
-    return env->cpu_index == 0;
-}
-
 DeviceState *cpu_get_current_apic(void)
 {
     if (cpu_single_env) {
@@ -913,10 +907,7 @@ void pc_acpi_smi_interrupt(void *opaque, int irq, int level)
 static void pc_cpu_reset(void *opaque)
 {
     X86CPU *cpu = opaque;
-    CPUX86State *env = &cpu->env;
-
     cpu_reset(CPU(cpu));
-    env->halted = !cpu_is_bsp(env);
 }
 
 static X86CPU *pc_new_cpu(const char *cpu_model)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 6b9659f..365c2ff 100644 (file)
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -1686,8 +1686,24 @@ static void x86_cpu_reset(CPUState *s)
     env->dr[7] = DR7_FIXED_1;
     cpu_breakpoint_remove_all(env, BP_CPU);
     cpu_watchpoint_remove_all(env, BP_CPU);
+
+#if !defined(CONFIG_USER_ONLY)
+    /* We hard-wire the BSP to the first CPU. */
+    if (env->cpu_index == 0) {
+        apic_designate_bsp(env->apic_state);
+    }
+
+    env->halted = !cpu_is_bsp(cpu);
+#endif
 }
 
+#ifndef CONFIG_USER_ONLY
+bool cpu_is_bsp(X86CPU *cpu)
+{
+    return cpu_get_apic_base(cpu->env.apic_state) & MSR_IA32_APICBASE_BSP;
+}
+#endif
+
 static void mce_init(X86CPU *cpu)
 {
     CPUX86State *cenv = &cpu->env;

diff --git a/target-i386/helper.c b/target-i386/helper.c
index d3af6ea..b748d90 100644 (file)
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1191,7 +1191,6 @@ void do_cpu_init(X86CPU *cpu)
     env->interrupt_request = sipi;
     env->pat = pat;
     apic_init_reset(env->apic_state);
-    env->halted = !cpu_is_bsp(env);
 }
 
 void do_cpu_sipi(X86CPU *cpu)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index e53c2f6..4cfb3fa 100644 (file)
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -584,11 +584,13 @@ int kvm_arch_init_vcpu(CPUX86State *env)
 
 void kvm_arch_reset_vcpu(CPUX86State *env)
 {
+    X86CPU *cpu = x86_env_get_cpu(env);
+
     env->exception_injected = -1;
     env->interrupt_injected = -1;
     env->xcr0 = 1;
     if (kvm_irqchip_in_kernel()) {
-        env->mp_state = cpu_is_bsp(env) ? KVM_MP_STATE_RUNNABLE :
+        env->mp_state = cpu_is_bsp(cpu) ? KVM_MP_STATE_RUNNABLE :
                                           KVM_MP_STATE_UNINITIALIZED;
     } else {
         env->mp_state = KVM_MP_STATE_RUNNABLE;