From: Nadav Amit <namit@cs.technion.ac.il>
Date: Wed, 1 Apr 2015 23:58:36 +0000 (+0300)
Subject: target-i386: clear bsp bit when designating bsp
X-Git-Tag: v2.3.0-rc2~2^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9cb11fd7539b5b787d8fb3834004804a58dd16ae;p=thirdparty%2Fqemu.git

target-i386: clear bsp bit when designating bsp

Since the BSP bit is writable on real hardware, during reset all the CPUs which
were not chosen to be the BSP should have their BSP bit cleared. This fix is
required for KVM to work correctly when it changes the BSP bit.

An additional fix is required for QEMU tcg to allow software to change the BSP
bit.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427932716-11800-1-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
index 0858b459433..042e960f426 100644
--- a/hw/intc/apic_common.c
+++ b/hw/intc/apic_common.c
@@ -215,14 +215,18 @@ void apic_init_reset(DeviceState *dev)
     }
 }
 
-void apic_designate_bsp(DeviceState *dev)
+void apic_designate_bsp(DeviceState *dev, bool bsp)
 {
     if (dev == NULL) {
         return;
     }
 
     APICCommonState *s = APIC_COMMON(dev);
-    s->apicbase |= MSR_IA32_APICBASE_BSP;
+    if (bsp) {
+        s->apicbase |= MSR_IA32_APICBASE_BSP;
+    } else {
+        s->apicbase &= ~MSR_IA32_APICBASE_BSP;
+    }
 }
 
 static void apic_reset_common(DeviceState *dev)
diff --git a/include/hw/i386/apic.h b/include/hw/i386/apic.h
index 1d48e027c3c..51eb6d38845 100644
--- a/include/hw/i386/apic.h
+++ b/include/hw/i386/apic.h
@@ -21,7 +21,7 @@ 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);
+void apic_designate_bsp(DeviceState *d, bool bsp);
 
 /* pc.c */
 DeviceState *cpu_get_current_apic(void);
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index b2d1c95df45..03b33cf3bd9 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2714,9 +2714,7 @@ static void x86_cpu_reset(CPUState *s)
 
 #if !defined(CONFIG_USER_ONLY)
     /* We hard-wire the BSP to the first CPU. */
-    if (s->cpu_index == 0) {
-        apic_designate_bsp(cpu->apic_state);
-    }
+    apic_designate_bsp(cpu->apic_state, s->cpu_index == 0);
 
     s->halted = !cpu_is_bsp(cpu);