Commit a07f953e authored by Igor Mammedov's avatar Igor Mammedov Committed by Eduardo Habkost
Browse files

exec: Set cpu_index only if it's not been explictly set 



It keeps the legacy behavior for all users that doesn't care
about stable cpu_index value, but would allow boards that
would support device_add/device_del to set stable cpu_index
that won't depend on order in which cpus are created/destroyed.

While at that simplify cpu_get_free_index() as cpu_index
generated by USER_ONLY and softmmu variants is the same
since none of the users support cpu-remove so far, except
of not yet released spapr/x86 device_add/delr, which
will be altered by follow up patches to set stable
cpu_index manually.

Signed-off-by: default avatarIgor Mammedov <imammedo@redhat.com>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent 8b1b8350

exec.c

+6 −38
Original line number Diff line number Diff line
@@ -598,30 +598,7 @@ AddressSpace *cpu_get_address_space(CPUState *cpu, int asidx) 
}

#endif



#ifndef CONFIG_USER_ONLY

static DECLARE_BITMAP(cpu_index_map, MAX_CPUMASK_BITS);



static int cpu_get_free_index(Error **errp)

{

    int cpu = find_first_zero_bit(cpu_index_map, MAX_CPUMASK_BITS);



    if (cpu >= MAX_CPUMASK_BITS) {

        error_setg(errp, "Trying to use more CPUs than max of %d",

                   MAX_CPUMASK_BITS);

        return -1;

    }



    bitmap_set(cpu_index_map, cpu, 1);

    return cpu;

}



static void cpu_release_index(CPUState *cpu)

{

    bitmap_clear(cpu_index_map, cpu->cpu_index, 1);

}

#else



static int cpu_get_free_index(Error **errp)

static int cpu_get_free_index(void)

{

    CPUState *some_cpu;

    int cpu_index = 0;
@@ -632,12 +609,6 @@ static int cpu_get_free_index(Error **errp) 
    return cpu_index;

}



static void cpu_release_index(CPUState *cpu)

{

    return;

}

#endif



void cpu_exec_exit(CPUState *cpu)

{

    CPUClass *cc = CPU_GET_CLASS(cpu);
@@ -651,8 +622,7 @@ void cpu_exec_exit(CPUState *cpu) 


    QTAILQ_REMOVE(&cpus, cpu, node);

    cpu->node.tqe_prev = NULL;

    cpu_release_index(cpu);

    cpu->cpu_index = -1;

    cpu->cpu_index = UNASSIGNED_CPU_INDEX;

    cpu_list_unlock();



    if (cc->vmsd != NULL) {
@@ -666,7 +636,7 @@ void cpu_exec_exit(CPUState *cpu) 
void cpu_exec_init(CPUState *cpu, Error **errp)

{

    CPUClass *cc ATTRIBUTE_UNUSED = CPU_GET_CLASS(cpu);

    Error *local_err = NULL;

    Error *local_err ATTRIBUTE_UNUSED = NULL;



    cpu->as = NULL;

    cpu->num_ases = 0;
@@ -690,11 +660,9 @@ void cpu_exec_init(CPUState *cpu, Error **errp) 
#endif



    cpu_list_lock();

    cpu->cpu_index = cpu_get_free_index(&local_err);

    if (local_err) {

        error_propagate(errp, local_err);

        cpu_list_unlock();

        return;

    if (cpu->cpu_index == UNASSIGNED_CPU_INDEX) {

        cpu->cpu_index = cpu_get_free_index();

        assert(cpu->cpu_index != UNASSIGNED_CPU_INDEX);

    }

    QTAILQ_INSERT_TAIL(&cpus, cpu, node);

    cpu_list_unlock();

include/qom/cpu.h

+2 −0
Original line number Diff line number Diff line
@@ -883,4 +883,6 @@ extern const struct VMStateDescription vmstate_cpu_common; 
    .offset = 0,                                                            \

}



#define UNASSIGNED_CPU_INDEX -1



#endif

qom/cpu.c

+1 −1
Original line number Diff line number Diff line
@@ -340,7 +340,7 @@ static void cpu_common_initfn(Object *obj) 
    CPUState *cpu = CPU(obj);

    CPUClass *cc = CPU_GET_CLASS(obj);



    cpu->cpu_index = -1;

    cpu->cpu_index = UNASSIGNED_CPU_INDEX;

    cpu->gdb_num_regs = cpu->gdb_num_g_regs = cc->gdb_num_core_regs;

    qemu_mutex_init(&cpu->work_mutex);

    QTAILQ_INIT(&cpu->breakpoints);