Commit 9cb11fd7 authored by Nadav Amit's avatar Nadav Amit Committed by Paolo Bonzini
Browse files

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: default avatarNadav Amit <namit@cs.technion.ac.il>
Message-Id: <1427932716-11800-1-git-send-email-namit@cs.technion.ac.il>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 420957a5

hw/intc/apic_common.c

+6 −2
Original line number Diff line number Diff line
@@ -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);

    if (bsp) {

        s->apicbase |= MSR_IA32_APICBASE_BSP;

    } else {

        s->apicbase &= ~MSR_IA32_APICBASE_BSP;

    }

}



static void apic_reset_common(DeviceState *dev)

include/hw/i386/apic.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

target-i386/cpu.c

+1 −3
Original line number Diff line number Diff line
@@ -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);