From 15af83ccafc175c7a61d39f998ac7eb43829e53c Mon Sep 17 00:00:00 2001

From: David Hildenbrand <david@redhat.com>

Date: Fri, 21 Dec 2018 15:36:07 +0000

Subject: [PATCH 05/22] s390x/tcg: properly implement the TOD

RH-Author: David Hildenbrand <david@redhat.com>

Message-id: <20181221153614.27961-6-david@redhat.com>

Patchwork-id: 83751

O-Subject: [RHEL-8.0 qemu-kvm v2 PATCH 05/12] s390x/tcg: properly implement the TOD

Bugzilla: 1653569

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

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: Thomas Huth <thuth@redhat.com>

Signed-off-by: David Hildenbrand <david@redhat.com>

Message-Id: <20180627134410.4901-6-david@redhat.com>

Signed-off-by: Cornelia Huck <cohuck@redhat.com>

(cherry picked from commit 7de3b1cdc67dcb572c1761c2051252e91a438b22)

Signed-off-by: David Hildenbrand <david@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 hw/s390x/tod-qemu.c        | 46 ++++++++++++++++++++++++++++++++++++++++++----

 hw/s390x/tod.c             | 11 +++++++++++

 include/hw/s390x/tod.h     | 19 +++++++++++++++++++

 target/s390x/cpu.c         |  7 -------

 target/s390x/cpu.h         |  1 -

 target/s390x/internal.h    | 16 ----------------

 target/s390x/misc_helper.c | 25 +++++++++++++++++++------

 target/s390x/tcg_s390x.h   | 18 ++++++++++++++++++

 8 files changed, 109 insertions(+), 34 deletions(-)

 create mode 100644 target/s390x/tcg_s390x.h

diff --git a/hw/s390x/tod-qemu.c b/hw/s390x/tod-qemu.c

index 03ea1ce..59c015c 100644

--- a/hw/s390x/tod-qemu.c

+++ b/hw/s390x/tod-qemu.c

@@ -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),

 };

diff --git a/hw/s390x/tod.c b/hw/s390x/tod.c

index 0501aff..1c63f41 100644

--- a/hw/s390x/tod.c

+++ b/hw/s390x/tod.c

@@ -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

diff --git a/include/hw/s390x/tod.h b/include/hw/s390x/tod.h

index 7096b57..413c0d7 100644

--- a/include/hw/s390x/tod.h

+++ b/include/hw/s390x/tod.h

@@ -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

diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c

index 5570741..f74d2a3 100644

--- a/target/s390x/cpu.c

+++ b/target/s390x/cpu.c

@@ -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"

@@ -276,9 +275,6 @@ 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;

@@ -287,9 +283,6 @@ 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);

diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h

index 04f9adf..6500f42 100644

--- a/target/s390x/cpu.h

+++ b/target/s390x/cpu.h

@@ -133,7 +133,6 @@ struct CPUS390XState {

     uint64_t cpuid;

 #endif

-    uint64_t tod_offset;

     QEMUTimer *tod_timer;

     QEMUTimer *cpu_timer;

diff --git a/target/s390x/internal.h b/target/s390x/internal.h

index d1ed06f..61a509d 100644

--- a/target/s390x/internal.h

+++ b/target/s390x/internal.h

@@ -237,22 +237,6 @@ enum cc_op {

     CC_OP_MAX

 };

-/* 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);

-}

-

 static inline hwaddr decode_basedisp_s(CPUS390XState *env, uint32_t ipb,

                                        uint8_t *ar)

 {

diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c

index 8b3b040..4f675c7 100644

--- a/target/s390x/misc_helper.c

+++ b/target/s390x/misc_helper.c

@@ -29,6 +29,8 @@

 #include "exec/address-spaces.h"

 #include "exec/exec-all.h"

 #include "exec/cpu_ldst.h"

+#include "qapi/error.h"

+#include "tcg_s390x.h"

 #if !defined(CONFIG_USER_ONLY)

 #include "sysemu/cpus.h"

@@ -40,6 +42,7 @@

 #include "hw/s390x/ioinst.h"

 #include "hw/s390x/s390-pci-inst.h"

 #include "hw/boards.h"

+#include "hw/s390x/tod.h"

 #endif

 /* #define DEBUG_HELPER */

@@ -139,17 +142,19 @@ void HELPER(spx)(CPUS390XState *env, uint64_t a1)

 /* Store Clock */

 uint64_t HELPER(stck)(CPUS390XState *env)

 {

-    uint64_t time;

+    S390TODState *td = s390_get_todstate();

+    S390TODClass *tdc = S390_TOD_GET_CLASS(td);

+    S390TOD tod;

-    time = env->tod_offset +

-        time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));

-

-    return time;

+    tdc->get(td, &tod, &error_abort);

+    return tod.low;

 }

 /* Set Clock Comparator */

 void HELPER(sckc)(CPUS390XState *env, uint64_t time)

 {

+    S390TODState *td = s390_get_todstate();

+

     if (time == -1ULL) {

         return;

     }

@@ -157,7 +162,7 @@ void HELPER(sckc)(CPUS390XState *env, uint64_t time)

     env->ckc = time;

     /* difference between origins */

-    time -= env->tod_offset;

+    time -= td->base.low;

     /* nanoseconds */

     time = tod2time(time);

@@ -165,6 +170,14 @@ void HELPER(sckc)(CPUS390XState *env, uint64_t time)

     timer_mod(env->tod_timer, time);

 }

+void tcg_s390_tod_updated(CPUState *cs, run_on_cpu_data opaque)

+{

+    S390CPU *cpu = S390_CPU(cs);

+    CPUS390XState *env = &cpu->env;

+

+    helper_sckc(env, env->ckc);

+}

+

 /* Set Tod Programmable Field */

 void HELPER(sckpf)(CPUS390XState *env, uint64_t r0)

 {

diff --git a/target/s390x/tcg_s390x.h b/target/s390x/tcg_s390x.h

new file mode 100644

index 0000000..4e308aa

--- /dev/null

+++ b/target/s390x/tcg_s390x.h

@@ -0,0 +1,18 @@

+/*

+ * QEMU TCG support -- s390x specific functions.

+ *

+ * Copyright 2018 Red Hat, Inc.

+ *

+ * Authors:

+ *   David Hildenbrand <david@redhat.com>

+ *

+ * This work is licensed under the terms of the GNU GPL, version 2 or later.

+ * See the COPYING file in the top-level directory.

+ */

+

+#ifndef TCG_S390X_H

+#define TCG_S390X_H

+

+void tcg_s390_tod_updated(CPUState *cs, run_on_cpu_data opaque);

+

+#endif /* TCG_S390X_H */

-- 

1.8.3.1