Commit 7de3b1cd authored by David Hildenbrand's avatar David Hildenbrand Committed by Cornelia Huck
Browse files

s390x/tcg: properly implement the TOD 



Right now, each CPU has its own TOD. Especially, the TOD will differ
based on creation time of a CPU - e.g. when hotplugging a CPU the times
will differ quite a lot, resulting in stall warnings in the guest.

Let's use a single TOD by implementing our new TOD device. Prepare it
for TOD-clock epoch extension.

Most importantly, whenever we set the TOD, we have to update the CKC
timer.

Introduce "tcg_s390x.h" just like "kvm_s390x.h" for tcg specific
function declarations that should not go into cpu.h.

Reviewed-by: default avatarThomas Huth <thuth@redhat.com>
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Message-Id: <20180627134410.4901-6-david@redhat.com>
Signed-off-by: default avatarCornelia Huck <cohuck@redhat.com>
parent f777b205

hw/s390x/tod-qemu.c

+42 −4
Original line number Diff line number Diff line
@@ -11,19 +11,43 @@ 
#include "qemu/osdep.h"

#include "qapi/error.h"

#include "hw/s390x/tod.h"

#include "qemu/timer.h"

#include "qemu/cutils.h"

#include "cpu.h"

#include "tcg_s390x.h"



static void qemu_s390_tod_get(const S390TODState *td, S390TOD *tod,

                              Error **errp)

{

    /* FIXME */

    tod->high = 0;

    tod->low = 0;

    *tod = td->base;



    tod->low += time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));

    if (tod->low < td->base.low) {

        tod->high++;

    }

}



static void qemu_s390_tod_set(S390TODState *td, const S390TOD *tod,

                              Error **errp)

{

    /* FIXME */

    CPUState *cpu;



    td->base = *tod;



    td->base.low -= time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));

    if (td->base.low > tod->low) {

        td->base.high--;

    }



    /*

     * The TOD has been changed and we have to recalculate the CKC values

     * for all CPUs. We do this asynchronously, as "SET CLOCK should be

     * issued only while all other activity on all CPUs .. has been

     * suspended".

     */

    CPU_FOREACH(cpu) {

        async_run_on_cpu(cpu, tcg_s390_tod_updated, RUN_ON_CPU_NULL);

    }

}



static void qemu_s390_tod_class_init(ObjectClass *oc, void *data)
@@ -34,10 +58,24 @@ static void qemu_s390_tod_class_init(ObjectClass *oc, void *data) 
    tdc->set = qemu_s390_tod_set;

}



static void qemu_s390_tod_init(Object *obj)

{

    S390TODState *td = S390_TOD(obj);

    struct tm tm;



    qemu_get_timedate(&tm, 0);

    td->base.high = 0;

    td->base.low = TOD_UNIX_EPOCH + (time2tod(mktimegm(&tm)) * 1000000000ULL);

    if (td->base.low < TOD_UNIX_EPOCH) {

        td->base.high += 1;

    }

}



static TypeInfo qemu_s390_tod_info = {

    .name = TYPE_QEMU_S390_TOD,

    .parent = TYPE_S390_TOD,

    .instance_size = sizeof(S390TODState),

    .instance_init = qemu_s390_tod_init,

    .class_init = qemu_s390_tod_class_init,

    .class_size = sizeof(S390TODClass),

};

hw/s390x/tod.c

+11 −0
Original line number Diff line number Diff line
@@ -30,6 +30,17 @@ void s390_init_tod(void) 
    qdev_init_nofail(DEVICE(obj));

}



S390TODState *s390_get_todstate(void)

{

    static S390TODState *ts;



    if (!ts) {

        ts = S390_TOD(object_resolve_path_type("", TYPE_S390_TOD, NULL));

    }



    return ts;

}



#define S390_TOD_CLOCK_VALUE_MISSING    0x00

#define S390_TOD_CLOCK_VALUE_PRESENT    0x01

include/hw/s390x/tod.h

+19 −0
Original line number Diff line number Diff line
@@ -30,6 +30,9 @@ typedef struct S390TOD { 
typedef struct S390TODState {

    /* private */

    DeviceState parent_obj;



    /* unused by KVM implementation */

    S390TOD base;

} S390TODState;



typedef struct S390TODClass {
@@ -41,6 +44,22 @@ typedef struct S390TODClass { 
    void (*set)(S390TODState *td, const S390TOD *tod, Error **errp);

} S390TODClass;



/* The value of the TOD clock for 1.1.1970. */

#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL



/* Converts ns to s390's clock format */

static inline uint64_t time2tod(uint64_t ns)

{

    return (ns << 9) / 125 + (((ns & 0xff10000000000000ull) / 125) << 9);

}



/* Converts s390's clock format to ns */

static inline uint64_t tod2time(uint64_t t)

{

    return ((t >> 9) * 125) + (((t & 0x1ff) * 125) >> 9);

}



void s390_init_tod(void);

S390TODState *s390_get_todstate(void);



#endif

target/s390x/cpu.c

+0 −7
Original line number Diff line number Diff line
@@ -30,7 +30,6 @@ 
#include "kvm_s390x.h"

#include "sysemu/kvm.h"

#include "qemu-common.h"

#include "qemu/cutils.h"

#include "qemu/timer.h"

#include "qemu/error-report.h"

#include "trace.h"
@@ -275,9 +274,6 @@ static void s390_cpu_initfn(Object *obj) 
    CPUState *cs = CPU(obj);

    S390CPU *cpu = S390_CPU(obj);

    CPUS390XState *env = &cpu->env;

#if !defined(CONFIG_USER_ONLY)

    struct tm tm;

#endif



    cs->env_ptr = env;

    cs->halted = 1;
@@ -286,9 +282,6 @@ static void s390_cpu_initfn(Object *obj) 
                        s390_cpu_get_crash_info_qom, NULL, NULL, NULL, NULL);

    s390_cpu_model_register_props(obj);

#if !defined(CONFIG_USER_ONLY)

    qemu_get_timedate(&tm, 0);

    env->tod_offset = TOD_UNIX_EPOCH +

                      (time2tod(mktimegm(&tm)) * 1000000000ULL);

    env->tod_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, s390x_tod_timer, cpu);

    env->cpu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, s390x_cpu_timer, cpu);

    s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);

target/s390x/cpu.h

+0 −1
Original line number Diff line number Diff line
@@ -130,7 +130,6 @@ struct CPUS390XState { 
    uint64_t cpuid;

#endif



    uint64_t tod_offset;

    QEMUTimer *tod_timer;



    QEMUTimer *cpu_timer;