Re: [Qemu-devel] [PATCH 2/3] s390: clear registers, psw and prefix at vcpu reset

[Alexander Graf]

On 23.11.2012, at 11:18, Jens Freimann wrote:

> When resetting vcpus on s390/kvm we have to clear registers, psw
> and prefix as described in the z/Architecture PoP, otherwise a
> reboot won't work. IPL PSW and prefix are set later on by the
> s390-ipl device reset code.
> 
> Signed-off-by: Jens Freimann <address@hidden>
> ---
> target-s390x/kvm.c | 26 +++++++++++++++++++++++++-
> 1 file changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
> index 94de764..b1b791e 100644
> --- a/target-s390x/kvm.c
> +++ b/target-s390x/kvm.c

This needs to go into generic vcpu reset code.


Alex

> @@ -85,7 +85,31 @@ int kvm_arch_init_vcpu(CPUS390XState *env)
> 
> void kvm_arch_reset_vcpu(CPUS390XState *env)
> {
> -    /* FIXME: add code to reset vcpu. */
> +    int i;
> +
> +    /* The initial reset call is needed here to reset in-kernel
> +     * vcpu data that we can't access directly from QEMU. Before
> +     * this ioctl cpu_synchronize_state() is called in common kvm
> +     * code (kvm-all). What remains is clearing registers and psw
> +     * in QEMU cpu state */
> +    if (kvm_vcpu_ioctl(env, KVM_S390_INITIAL_RESET, NULL)) {
> +        perror("Can't reset vcpu\n");
> +    }
> +    env->halted = 1;
> +    env->exception_index = EXCP_HLT;
> +    for (i = 0; i < 16; i++) {
> +        env->regs[i] = 0;
> +        env->aregs[i] = 0;
> +        env->cregs[i] = 0;
> +        env->fregs[i].ll = 0;
> +    }
> +    /* architectured initial values for CR 0 and 14 */
> +    env->cregs[0] = 0xE0UL;
> +    env->cregs[14] = 0xC2000000UL;
> +    env->fpc = 0;
> +    env->psw.mask = 0;
> +    env->psw.addr = 0;
> +    env->psa = 0;
> }
> 
> int kvm_arch_put_registers(CPUS390XState *env, int level)
> -- 
> 1.7.12.4
>