Re: [Qemu-devel] [PATCH v4] s390: Add CPU reset handler

[Alexander Graf]

On 07.01.2013, at 16:27, Jens Freimann wrote:

> Add a CPU reset handler to have all CPUs in a PoP compliant
> state.
> 
> Signed-off-by: Jens Freimann <address@hidden>

Thanks, applied to s390-next.


Alex

> ---
> v3 -> v4:
> * don't set psw_mask to z/Architecture in cpu_reset as it
>  is done by the ipl device code later on
> * make sure patch compiles and runs with s390x-linux-user
>  (simple test by running busybox on x86)
> 
> v2 -> v3:
> * remove FIXME
> * separate parent reset from local reset by adding a white line
> * use defines for register reset values
> 
> 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 | 36 ++++++++++++++++++++++++++++++++++--
> target-s390x/kvm.c |  9 ++++++++-
> 2 files changed, 42 insertions(+), 3 deletions(-)
> 
> diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
> index 249f063..146f079 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
> @@ -18,12 +19,19 @@
>  * 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"
> +#ifndef CONFIG_USER_ONLY
> +#include "hw/hw.h"
> +#endif
> #include "qemu-common.h"
> #include "qemu/timer.h"
> 
> +#define CR0_RESET       0xE0UL
> +#define CR14_RESET      0xC2000000UL;
> 
> /* CPUClass::reset() */
> static void s390_cpu_reset(CPUState *s)
> @@ -37,14 +45,33 @@ static void s390_cpu_reset(CPUState *s)
>         log_cpu_state(env, 0);
>     }
> 
> +    s390_del_running_cpu(env);
> +
>     scc->parent_reset(s);
> 
>     memset(env, 0, offsetof(CPUS390XState, breakpoints));
> -    /* FIXME: reset vector? */
> +
> +    /* architectured initial values for CR 0 and 14 */
> +    env->cregs[0] = CR0_RESET;
> +    env->cregs[14] = CR14_RESET;
> +    /* 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 */
> +#if !defined(CONFIG_USER_ONLY)
> +    env->halted = 1;
> +#endif
>     tlb_flush(env, 1);
> -    s390_add_running_cpu(env);
> }
> 
> +#if !defined(CONFIG_USER_ONLY)
> +static void s390_cpu_machine_reset_cb(void *opaque)
> +{
> +    S390CPU *cpu = opaque;
> +
> +    cpu_reset(CPU(cpu));
> +}
> +#endif
> +
> static void s390_cpu_initfn(Object *obj)
> {
>     S390CPU *cpu = S390_CPU(obj);
> @@ -56,12 +83,17 @@ static void s390_cpu_initfn(Object *obj)
> 
>     cpu_exec_init(env);
> #if !defined(CONFIG_USER_ONLY)
> +    qemu_register_reset(s390_cpu_machine_reset_cb, cpu);
>     qemu_get_timedate(&tm, 0);
>     env->tod_offset = TOD_UNIX_EPOCH +
>                       (time2tod(mktimegm(&tm)) * 1000000000ULL);
>     env->tod_basetime = 0;
>     env->tod_timer = qemu_new_timer_ns(vm_clock, s390x_tod_timer, cpu);
>     env->cpu_timer = qemu_new_timer_ns(vm_clock, s390x_cpu_timer, cpu);
> +    /* 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;
> #endif
>     env->cpu_num = cpu_num++;
>     env->ext_index = -1;
> diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
> index 6ec5e6d..f116a43 100644
> --- a/target-s390x/kvm.c
> +++ b/target-s390x/kvm.c
> @@ -85,7 +85,14 @@ int kvm_arch_init_vcpu(CPUState *cpu)
> 
> void kvm_arch_reset_vcpu(CPUState *cpu)
> {
> -    /* 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(cpu, KVM_S390_INITIAL_RESET, NULL)) {
> +        perror("Can't reset vcpu\n");
> +    }
> }
> 
> int kvm_arch_put_registers(CPUState *cs, int level)
> -- 
> 1.7.12.4
>