Patchwork [2/3] s390: Add CPU reset handler

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Submitter Jens Freimann
Date Dec. 14, 2012, 4:46 p.m.
Message ID <1355503606-54131-3-git-send-email-jfrei@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/206523/
State New
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Comments

Jens Freimann - Dec. 14, 2012, 4:46 p.m.
Add a CPU reset handler to have all CPUs in a PoP compliant
state.

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>

---
v2 -> v3: 
* explain in comment which code sets cpu 0 to running during IPL

v1 -> v2:
* move setting of control registers and psa to s390_cpu_reset
  and call it from the new s390_machine_cpu_reset_cb()
  This makes it more similar to how it is done on x86
* in s390_cpu_reset() set env->halted state of cpu after
  the memset. This is needed to keep our s390_cpu_running
  counter in sync when s390_cpu_reset is called via the
  qemu_devices_reset path
* set env->halted state in s390_cpu_initfn to 1 to avoid
  decrementing the cpu counter during first reset
---
 target-s390x/cpu.c | 32 ++++++++++++++++++++++++++++++--
 target-s390x/kvm.c |  9 ++++++++-
 2 files changed, 38 insertions(+), 3 deletions(-)
Andreas Färber - Dec. 16, 2012, 3:30 p.m.
Am 14.12.2012 17:46, schrieb Jens Freimann:
> Add a CPU reset handler to have all CPUs in a PoP compliant
> state.
> 
> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>

The logic looks okay now. Some comments inline.

> ---
> v2 -> v3: 
> * explain in comment which code sets cpu 0 to running during IPL
> 
> v1 -> v2:
> * move setting of control registers and psa to s390_cpu_reset
>   and call it from the new s390_machine_cpu_reset_cb()
>   This makes it more similar to how it is done on x86
> * in s390_cpu_reset() set env->halted state of cpu after
>   the memset. This is needed to keep our s390_cpu_running
>   counter in sync when s390_cpu_reset is called via the
>   qemu_devices_reset path
> * set env->halted state in s390_cpu_initfn to 1 to avoid
>   decrementing the cpu counter during first reset
> ---
>  target-s390x/cpu.c | 32 ++++++++++++++++++++++++++++++--
>  target-s390x/kvm.c |  9 ++++++++-
>  2 files changed, 38 insertions(+), 3 deletions(-)
> 
> diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
> index 619b202..75d4036 100644
> --- a/target-s390x/cpu.c
> +++ b/target-s390x/cpu.c
> @@ -4,6 +4,7 @@
>   * Copyright (c) 2009 Ulrich Hecht
>   * Copyright (c) 2011 Alexander Graf
>   * Copyright (c) 2012 SUSE LINUX Products GmbH
> + * Copyright (c) 2012 IBM Corp.
>   *
>   * This library is free software; you can redistribute it and/or
>   * modify it under the terms of the GNU Lesser General Public
> @@ -18,9 +19,13 @@
>   * You should have received a copy of the GNU Lesser General Public
>   * License along with this library; if not, see
>   * <http://www.gnu.org/licenses/lgpl-2.1.html>
> + * Contributions after 2012-12-11 are licensed under the terms of the
> + * GNU GPL, version 2 or (at your option) any later version.
> + *
>   */
>  
>  #include "cpu.h"
> +#include "hw/hw.h"
>  #include "qemu-common.h"
>  #include "qemu-timer.h"
>  
> @@ -37,12 +42,30 @@ static void s390_cpu_reset(CPUState *s)
>          log_cpu_state(env, 0);
>      }
>  
> -    scc->parent_reset(s);
> +    s390_del_running_cpu(env);
>  
> +    scc->parent_reset(s);

If this gets respun, a white line separating the parent reset from the
local reset would be nice. :)

>      memset(env, 0, offsetof(CPUS390XState, breakpoints));
> +
> +    /* architectured initial values for CR 0 and 14 */
> +    env->cregs[0] = 0xE0UL;
> +    env->cregs[14] = 0xC2000000UL;
> +    /* set to z/Architecture mode */
> +    env->psw.mask = 0x0000000180000000ULL;
> +    env->psa = 0;
> +    /* set halted to 1 to make sure we can add the cpu in
> +     * s390_ipl_cpu code, where env->halted is set back to 0
> +     * after incrementing the cpu counter */
> +    env->halted = 1;
>      /* FIXME: reset vector? */

Do the above added cregs/psw/psa reset values resolve this FIXME? Or
does that refer to something different?

>      tlb_flush(env, 1);
> -    s390_add_running_cpu(env);
> +}
> +
> +static void s390_cpu_machine_reset_cb(void *opaque)
> +{
> +    S390CPU *cpu = opaque;
> +
> +    cpu_reset(CPU(cpu));
>  }
>  
>  static void s390_cpu_initfn(Object *obj)
> @@ -66,7 +89,12 @@ static void s390_cpu_initfn(Object *obj)
>      env->cpu_num = cpu_num++;
>      env->ext_index = -1;
>  
> +    /* set env->halted state to 1 to avoid decrementing the running
> +     * cpu counter in s390_cpu_reset to a negative number at 
> +     * initial ipl */
> +    env->halted = 1;
>      cpu_reset(CPU(cpu));
> +    qemu_register_reset(s390_cpu_machine_reset_cb, cpu);

Since we register the reset handler in instance_init, we should
unregister it in a instance_finalize callback (uninitfn?). Since we do
not hot-unplug s390 CPUs yet to my knowledge, that could be done in a
follow-up.

(For x86 it it registered in the provisional realize function and not
unregistered lacking a matching unrealization mechanism today; elsewhere
reset registration is done in the machine.)

>  }
>  
>  static void s390_cpu_class_init(ObjectClass *oc, void *data)
> diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
> index 94de764..fda9f1f 100644
> --- a/target-s390x/kvm.c
> +++ b/target-s390x/kvm.c
> @@ -85,7 +85,14 @@ int kvm_arch_init_vcpu(CPUS390XState *env)
>  
>  void kvm_arch_reset_vcpu(CPUS390XState *env)
>  {

Note to Alex: In my upcoming KVM CPUState series, this argument type
changes to CPUState ...

> -    /* FIXME: add code to reset vcpu. */
> +   /* The initial reset call is needed here to reset in-kernel
> +    * vcpu data that we can't access directly from QEMU
> +    * (i.e. with older kernels which don't support sync_regs/ONE_REG).
> +    * Before this ioctl cpu_synchronize_state() is called in common kvm
> +    * code (kvm-all) */
> +    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL)) {

... but so does the argument for kvm_vcpu_ioctl(), so merging becomes a
trivial env -> cpu change.

> +        perror("Can't reset vcpu\n");
> +    }
>  }
>  
>  int kvm_arch_put_registers(CPUS390XState *env, int level)

Andreas
Jens Freimann - Dec. 17, 2012, 8:49 a.m.
On Sun, Dec 16, 2012 at 04:30:21PM +0100, Andreas Färber wrote:
> Am 14.12.2012 17:46, schrieb Jens Freimann:
> > Add a CPU reset handler to have all CPUs in a PoP compliant
> > state.
> > 
> > Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
> 
> The logic looks okay now. Some comments inline.
> 
> > ---
> > v2 -> v3: 
> > * explain in comment which code sets cpu 0 to running during IPL
> > 
> > v1 -> v2:
> > * move setting of control registers and psa to s390_cpu_reset
> >   and call it from the new s390_machine_cpu_reset_cb()
> >   This makes it more similar to how it is done on x86
> > * in s390_cpu_reset() set env->halted state of cpu after
> >   the memset. This is needed to keep our s390_cpu_running
> >   counter in sync when s390_cpu_reset is called via the
> >   qemu_devices_reset path
> > * set env->halted state in s390_cpu_initfn to 1 to avoid
> >   decrementing the cpu counter during first reset
> > ---
> >  target-s390x/cpu.c | 32 ++++++++++++++++++++++++++++++--
> >  target-s390x/kvm.c |  9 ++++++++-
> >  2 files changed, 38 insertions(+), 3 deletions(-)
> > 
> > diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
> > index 619b202..75d4036 100644
> > --- a/target-s390x/cpu.c
> > +++ b/target-s390x/cpu.c
> > @@ -4,6 +4,7 @@
> >   * Copyright (c) 2009 Ulrich Hecht
> >   * Copyright (c) 2011 Alexander Graf
> >   * Copyright (c) 2012 SUSE LINUX Products GmbH
> > + * Copyright (c) 2012 IBM Corp.
> >   *
> >   * This library is free software; you can redistribute it and/or
> >   * modify it under the terms of the GNU Lesser General Public
> > @@ -18,9 +19,13 @@
> >   * You should have received a copy of the GNU Lesser General Public
> >   * License along with this library; if not, see
> >   * <http://www.gnu.org/licenses/lgpl-2.1.html>
> > + * Contributions after 2012-12-11 are licensed under the terms of the
> > + * GNU GPL, version 2 or (at your option) any later version.
> > + *
> >   */
> >  
> >  #include "cpu.h"
> > +#include "hw/hw.h"
> >  #include "qemu-common.h"
> >  #include "qemu-timer.h"
> >  
> > @@ -37,12 +42,30 @@ static void s390_cpu_reset(CPUState *s)
> >          log_cpu_state(env, 0);
> >      }
> >  
> > -    scc->parent_reset(s);
> > +    s390_del_running_cpu(env);
> >  
> > +    scc->parent_reset(s);
> 
> If this gets respun, a white line separating the parent reset from the
> local reset would be nice. :)

Ok

> >      memset(env, 0, offsetof(CPUS390XState, breakpoints));
> > +
> > +    /* architectured initial values for CR 0 and 14 */
> > +    env->cregs[0] = 0xE0UL;
> > +    env->cregs[14] = 0xC2000000UL;
> > +    /* set to z/Architecture mode */
> > +    env->psw.mask = 0x0000000180000000ULL;
> > +    env->psa = 0;
> > +    /* set halted to 1 to make sure we can add the cpu in
> > +     * s390_ipl_cpu code, where env->halted is set back to 0
> > +     * after incrementing the cpu counter */
> > +    env->halted = 1;
> >      /* FIXME: reset vector? */
> 
> Do the above added cregs/psw/psa reset values resolve this FIXME? Or
> does that refer to something different?

Yes, together with the ipl device this fixme is resolved.

> >      tlb_flush(env, 1);
> > -    s390_add_running_cpu(env);
> > +}
> > +
> > +static void s390_cpu_machine_reset_cb(void *opaque)
> > +{
> > +    S390CPU *cpu = opaque;
> > +
> > +    cpu_reset(CPU(cpu));
> >  }
> >  
> >  static void s390_cpu_initfn(Object *obj)
> > @@ -66,7 +89,12 @@ static void s390_cpu_initfn(Object *obj)
> >      env->cpu_num = cpu_num++;
> >      env->ext_index = -1;
> >  
> > +    /* set env->halted state to 1 to avoid decrementing the running
> > +     * cpu counter in s390_cpu_reset to a negative number at 
> > +     * initial ipl */
> > +    env->halted = 1;
> >      cpu_reset(CPU(cpu));
> > +    qemu_register_reset(s390_cpu_machine_reset_cb, cpu);
> 
> Since we register the reset handler in instance_init, we should
> unregister it in a instance_finalize callback (uninitfn?). Since we do
> not hot-unplug s390 CPUs yet to my knowledge, that could be done in a
> follow-up.
> 
> (For x86 it it registered in the provisional realize function and not
> unregistered lacking a matching unrealization mechanism today; elsewhere
> reset registration is done in the machine.)

Ok, I'll keep that in mind and send a followup patch.

Thanks!
Jens

> 
> >  }
> >  
> >  static void s390_cpu_class_init(ObjectClass *oc, void *data)
> > diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
> > index 94de764..fda9f1f 100644
> > --- a/target-s390x/kvm.c
> > +++ b/target-s390x/kvm.c
> > @@ -85,7 +85,14 @@ int kvm_arch_init_vcpu(CPUS390XState *env)
> >  
> >  void kvm_arch_reset_vcpu(CPUS390XState *env)
> >  {
> 
> Note to Alex: In my upcoming KVM CPUState series, this argument type
> changes to CPUState ...
> 
> > -    /* FIXME: add code to reset vcpu. */
> > +   /* The initial reset call is needed here to reset in-kernel
> > +    * vcpu data that we can't access directly from QEMU
> > +    * (i.e. with older kernels which don't support sync_regs/ONE_REG).
> > +    * Before this ioctl cpu_synchronize_state() is called in common kvm
> > +    * code (kvm-all) */
> > +    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL)) {
> 
> ... but so does the argument for kvm_vcpu_ioctl(), so merging becomes a
> trivial env -> cpu change.
> 
> > +        perror("Can't reset vcpu\n");
> > +    }
> >  }
> >  
> >  int kvm_arch_put_registers(CPUS390XState *env, int level)
> 
> Andreas
> 
> -- 
> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
>
Alexander Graf - Dec. 17, 2012, 2:49 p.m.
On 14.12.2012, at 17:46, Jens Freimann wrote:

> Add a CPU reset handler to have all CPUs in a PoP compliant
> state.
> 
> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
> 
> ---
> v2 -> v3: 
> * explain in comment which code sets cpu 0 to running during IPL
> 
> v1 -> v2:
> * move setting of control registers and psa to s390_cpu_reset
>  and call it from the new s390_machine_cpu_reset_cb()
>  This makes it more similar to how it is done on x86
> * in s390_cpu_reset() set env->halted state of cpu after
>  the memset. This is needed to keep our s390_cpu_running
>  counter in sync when s390_cpu_reset is called via the
>  qemu_devices_reset path
> * set env->halted state in s390_cpu_initfn to 1 to avoid
>  decrementing the cpu counter during first reset
> ---
> target-s390x/cpu.c | 32 ++++++++++++++++++++++++++++++--
> target-s390x/kvm.c |  9 ++++++++-
> 2 files changed, 38 insertions(+), 3 deletions(-)
> 
> diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
> index 619b202..75d4036 100644
> --- a/target-s390x/cpu.c
> +++ b/target-s390x/cpu.c
> @@ -4,6 +4,7 @@
>  * Copyright (c) 2009 Ulrich Hecht
>  * Copyright (c) 2011 Alexander Graf
>  * Copyright (c) 2012 SUSE LINUX Products GmbH
> + * Copyright (c) 2012 IBM Corp.
>  *
>  * This library is free software; you can redistribute it and/or
>  * modify it under the terms of the GNU Lesser General Public
> @@ -18,9 +19,13 @@
>  * You should have received a copy of the GNU Lesser General Public
>  * License along with this library; if not, see
>  * <http://www.gnu.org/licenses/lgpl-2.1.html>
> + * Contributions after 2012-12-11 are licensed under the terms of the
> + * GNU GPL, version 2 or (at your option) any later version.
> + *
>  */
> 
> #include "cpu.h"
> +#include "hw/hw.h"
> #include "qemu-common.h"
> #include "qemu-timer.h"
> 
> @@ -37,12 +42,30 @@ static void s390_cpu_reset(CPUState *s)
>         log_cpu_state(env, 0);
>     }
> 
> -    scc->parent_reset(s);
> +    s390_del_running_cpu(env);
> 
> +    scc->parent_reset(s);
>     memset(env, 0, offsetof(CPUS390XState, breakpoints));

Shouldn't parent_reset already do the memset?

> +
> +    /* architectured initial values for CR 0 and 14 */
> +    env->cregs[0] = 0xE0UL;
> +    env->cregs[14] = 0xC2000000UL;
> +    /* set to z/Architecture mode */
> +    env->psw.mask = 0x0000000180000000ULL;

While at it, please convert this into something that uses #define's to make things readable.


Alex

> +    env->psa = 0;
> +    /* set halted to 1 to make sure we can add the cpu in
> +     * s390_ipl_cpu code, where env->halted is set back to 0
> +     * after incrementing the cpu counter */
> +    env->halted = 1;
>     /* FIXME: reset vector? */
>     tlb_flush(env, 1);
> -    s390_add_running_cpu(env);
> +}
> +
> +static void s390_cpu_machine_reset_cb(void *opaque)
> +{
> +    S390CPU *cpu = opaque;
> +
> +    cpu_reset(CPU(cpu));
> }
> 
> static void s390_cpu_initfn(Object *obj)
> @@ -66,7 +89,12 @@ static void s390_cpu_initfn(Object *obj)
>     env->cpu_num = cpu_num++;
>     env->ext_index = -1;
> 
> +    /* set env->halted state to 1 to avoid decrementing the running
> +     * cpu counter in s390_cpu_reset to a negative number at 
> +     * initial ipl */
> +    env->halted = 1;
>     cpu_reset(CPU(cpu));
> +    qemu_register_reset(s390_cpu_machine_reset_cb, cpu);
> }
> 
> static void s390_cpu_class_init(ObjectClass *oc, void *data)
> diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
> index 94de764..fda9f1f 100644
> --- a/target-s390x/kvm.c
> +++ b/target-s390x/kvm.c
> @@ -85,7 +85,14 @@ int kvm_arch_init_vcpu(CPUS390XState *env)
> 
> void kvm_arch_reset_vcpu(CPUS390XState *env)
> {
> -    /* FIXME: add code to reset vcpu. */
> +   /* The initial reset call is needed here to reset in-kernel
> +    * vcpu data that we can't access directly from QEMU
> +    * (i.e. with older kernels which don't support sync_regs/ONE_REG).
> +    * Before this ioctl cpu_synchronize_state() is called in common kvm
> +    * code (kvm-all) */
> +    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL)) {
> +        perror("Can't reset vcpu\n");
> +    }
> }
> 
> int kvm_arch_put_registers(CPUS390XState *env, int level)
> -- 
> 1.7.12.4
>
Jens Freimann - Dec. 17, 2012, 3:41 p.m.
On Mon, Dec 17, 2012 at 03:49:41PM +0100, Alexander Graf wrote:
> 
> On 14.12.2012, at 17:46, Jens Freimann wrote:
> 
> > Add a CPU reset handler to have all CPUs in a PoP compliant
> > state.
> > 
> > Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
> > 
> > ---
> > v2 -> v3: 
> > * explain in comment which code sets cpu 0 to running during IPL
> > 
> > v1 -> v2:
> > * move setting of control registers and psa to s390_cpu_reset
> >  and call it from the new s390_machine_cpu_reset_cb()
> >  This makes it more similar to how it is done on x86
> > * in s390_cpu_reset() set env->halted state of cpu after
> >  the memset. This is needed to keep our s390_cpu_running
> >  counter in sync when s390_cpu_reset is called via the
> >  qemu_devices_reset path
> > * set env->halted state in s390_cpu_initfn to 1 to avoid
> >  decrementing the cpu counter during first reset
> > ---
> > target-s390x/cpu.c | 32 ++++++++++++++++++++++++++++++--
> > target-s390x/kvm.c |  9 ++++++++-
> > 2 files changed, 38 insertions(+), 3 deletions(-)
> > 
> > diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
> > index 619b202..75d4036 100644
> > --- a/target-s390x/cpu.c
> > +++ b/target-s390x/cpu.c
> > @@ -4,6 +4,7 @@
> >  * Copyright (c) 2009 Ulrich Hecht
> >  * Copyright (c) 2011 Alexander Graf
> >  * Copyright (c) 2012 SUSE LINUX Products GmbH
> > + * Copyright (c) 2012 IBM Corp.
> >  *
> >  * This library is free software; you can redistribute it and/or
> >  * modify it under the terms of the GNU Lesser General Public
> > @@ -18,9 +19,13 @@
> >  * You should have received a copy of the GNU Lesser General Public
> >  * License along with this library; if not, see
> >  * <http://www.gnu.org/licenses/lgpl-2.1.html>
> > + * Contributions after 2012-12-11 are licensed under the terms of the
> > + * GNU GPL, version 2 or (at your option) any later version.
> > + *
> >  */
> > 
> > #include "cpu.h"
> > +#include "hw/hw.h"
> > #include "qemu-common.h"
> > #include "qemu-timer.h"
> > 
> > @@ -37,12 +42,30 @@ static void s390_cpu_reset(CPUState *s)
> >         log_cpu_state(env, 0);
> >     }
> > 
> > -    scc->parent_reset(s);
> > +    s390_del_running_cpu(env);
> > 
> > +    scc->parent_reset(s);
> >     memset(env, 0, offsetof(CPUS390XState, breakpoints));
> 
> Shouldn't parent_reset already do the memset?

parent_reset is cpu_common_reset() in qom/cpu.c and that
is an empty function as of now. It's what ARM and x86 do as well.

> > +
> > +    /* architectured initial values for CR 0 and 14 */
> > +    env->cregs[0] = 0xE0UL;
> > +    env->cregs[14] = 0xC2000000UL;
> > +    /* set to z/Architecture mode */
> > +    env->psw.mask = 0x0000000180000000ULL;
> 
> While at it, please convert this into something that uses #define's to make things readable.

ok

Jens

> 
> Alex
> 
> > +    env->psa = 0;
> > +    /* set halted to 1 to make sure we can add the cpu in
> > +     * s390_ipl_cpu code, where env->halted is set back to 0
> > +     * after incrementing the cpu counter */
> > +    env->halted = 1;
> >     /* FIXME: reset vector? */
> >     tlb_flush(env, 1);
> > -    s390_add_running_cpu(env);
> > +}
> > +
> > +static void s390_cpu_machine_reset_cb(void *opaque)
> > +{
> > +    S390CPU *cpu = opaque;
> > +
> > +    cpu_reset(CPU(cpu));
> > }
> > 
> > static void s390_cpu_initfn(Object *obj)
> > @@ -66,7 +89,12 @@ static void s390_cpu_initfn(Object *obj)
> >     env->cpu_num = cpu_num++;
> >     env->ext_index = -1;
> > 
> > +    /* set env->halted state to 1 to avoid decrementing the running
> > +     * cpu counter in s390_cpu_reset to a negative number at 
> > +     * initial ipl */
> > +    env->halted = 1;
> >     cpu_reset(CPU(cpu));
> > +    qemu_register_reset(s390_cpu_machine_reset_cb, cpu);
> > }
> > 
> > static void s390_cpu_class_init(ObjectClass *oc, void *data)
> > diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
> > index 94de764..fda9f1f 100644
> > --- a/target-s390x/kvm.c
> > +++ b/target-s390x/kvm.c
> > @@ -85,7 +85,14 @@ int kvm_arch_init_vcpu(CPUS390XState *env)
> > 
> > void kvm_arch_reset_vcpu(CPUS390XState *env)
> > {
> > -    /* FIXME: add code to reset vcpu. */
> > +   /* The initial reset call is needed here to reset in-kernel
> > +    * vcpu data that we can't access directly from QEMU
> > +    * (i.e. with older kernels which don't support sync_regs/ONE_REG).
> > +    * Before this ioctl cpu_synchronize_state() is called in common kvm
> > +    * code (kvm-all) */
> > +    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL)) {
> > +        perror("Can't reset vcpu\n");
> > +    }
> > }
> > 
> > int kvm_arch_put_registers(CPUS390XState *env, int level)
> > -- 
> > 1.7.12.4
> > 
>
Andreas Färber - Dec. 17, 2012, 5:21 p.m.
Am 17.12.2012 15:49, schrieb Alexander Graf:
> 
> On 14.12.2012, at 17:46, Jens Freimann wrote:
> 
>> @@ -37,12 +42,30 @@ static void s390_cpu_reset(CPUState *s)
>>         log_cpu_state(env, 0);
>>     }
>>
>> -    scc->parent_reset(s);
>> +    s390_del_running_cpu(env);
>>
>> +    scc->parent_reset(s);
>>     memset(env, 0, offsetof(CPUS390XState, breakpoints));
> 
> Shouldn't parent_reset already do the memset?

No, because "env" location and size are specific to S390CPU.

And yes, it is ugly boilerplate code, but it cannot be solved with my
CPU_COMMON field movements alone (which partially add explicit reset
code based on the field location), there's quite a large number of
per-target fields that get reset that way, some intentionally, some
accidentally. ;-)

Andreas
Alexander Graf - Dec. 17, 2012, 5:27 p.m.
On 17.12.2012, at 18:21, Andreas Färber wrote:

> Am 17.12.2012 15:49, schrieb Alexander Graf:
>> 
>> On 14.12.2012, at 17:46, Jens Freimann wrote:
>> 
>>> @@ -37,12 +42,30 @@ static void s390_cpu_reset(CPUState *s)
>>>        log_cpu_state(env, 0);
>>>    }
>>> 
>>> -    scc->parent_reset(s);
>>> +    s390_del_running_cpu(env);
>>> 
>>> +    scc->parent_reset(s);
>>>    memset(env, 0, offsetof(CPUS390XState, breakpoints));
>> 
>> Shouldn't parent_reset already do the memset?
> 
> No, because "env" location and size are specific to S390CPU.
> 
> And yes, it is ugly boilerplate code, but it cannot be solved with my
> CPU_COMMON field movements alone (which partially add explicit reset
> code based on the field location), there's quite a large number of
> per-target fields that get reset that way, some intentionally, some
> accidentally. ;-)

I see :)


Alex

Patch

diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
index 619b202..75d4036 100644
--- a/target-s390x/cpu.c
+++ b/target-s390x/cpu.c
@@ -4,6 +4,7 @@ 
  * Copyright (c) 2009 Ulrich Hecht
  * Copyright (c) 2011 Alexander Graf
  * Copyright (c) 2012 SUSE LINUX Products GmbH
+ * Copyright (c) 2012 IBM Corp.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -18,9 +19,13 @@ 
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, see
  * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ * Contributions after 2012-12-11 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ *
  */
 
 #include "cpu.h"
+#include "hw/hw.h"
 #include "qemu-common.h"
 #include "qemu-timer.h"
 
@@ -37,12 +42,30 @@  static void s390_cpu_reset(CPUState *s)
         log_cpu_state(env, 0);
     }
 
-    scc->parent_reset(s);
+    s390_del_running_cpu(env);
 
+    scc->parent_reset(s);
     memset(env, 0, offsetof(CPUS390XState, breakpoints));
+
+    /* architectured initial values for CR 0 and 14 */
+    env->cregs[0] = 0xE0UL;
+    env->cregs[14] = 0xC2000000UL;
+    /* set to z/Architecture mode */
+    env->psw.mask = 0x0000000180000000ULL;
+    env->psa = 0;
+    /* set halted to 1 to make sure we can add the cpu in
+     * s390_ipl_cpu code, where env->halted is set back to 0
+     * after incrementing the cpu counter */
+    env->halted = 1;
     /* FIXME: reset vector? */
     tlb_flush(env, 1);
-    s390_add_running_cpu(env);
+}
+
+static void s390_cpu_machine_reset_cb(void *opaque)
+{
+    S390CPU *cpu = opaque;
+
+    cpu_reset(CPU(cpu));
 }
 
 static void s390_cpu_initfn(Object *obj)
@@ -66,7 +89,12 @@  static void s390_cpu_initfn(Object *obj)
     env->cpu_num = cpu_num++;
     env->ext_index = -1;
 
+    /* set env->halted state to 1 to avoid decrementing the running
+     * cpu counter in s390_cpu_reset to a negative number at 
+     * initial ipl */
+    env->halted = 1;
     cpu_reset(CPU(cpu));
+    qemu_register_reset(s390_cpu_machine_reset_cb, cpu);
 }
 
 static void s390_cpu_class_init(ObjectClass *oc, void *data)
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index 94de764..fda9f1f 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -85,7 +85,14 @@  int kvm_arch_init_vcpu(CPUS390XState *env)
 
 void kvm_arch_reset_vcpu(CPUS390XState *env)
 {
-    /* FIXME: add code to reset vcpu. */
+   /* The initial reset call is needed here to reset in-kernel
+    * vcpu data that we can't access directly from QEMU
+    * (i.e. with older kernels which don't support sync_regs/ONE_REG).
+    * Before this ioctl cpu_synchronize_state() is called in common kvm
+    * code (kvm-all) */
+    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL)) {
+        perror("Can't reset vcpu\n");
+    }
 }
 
 int kvm_arch_put_registers(CPUS390XState *env, int level)