Re: [Qemu-devel] [PATCH for-2.1 1/1] s390x/kvm: synchronize guest floating point registers

[Alexander Graf <agraf@suse.de>]

On 11.07.14 12:38, Cornelia Huck wrote:
> From: "Jason J. Herne" <jjherne@us.ibm.com>
>
> Add code to kvm_arch_get_registers and kvm_arch_put_registers to
> save/restore floating point registers. This missing sync was
> unnoticed until migration of userspace that uses fprs.
>
> Signed-off-by: Jason J. Herne <jjherne@us.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> [Update patch to latest upstream]
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> ---
>   target-s390x/kvm.c |   23 +++++++++++++++++++++++
>   1 file changed, 23 insertions(+)
>
> diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
> index a6e587b..144189b 100644
> --- a/target-s390x/kvm.c
> +++ b/target-s390x/kvm.c
> @@ -207,6 +207,7 @@ int kvm_arch_put_registers(CPUState *cs, int level)
>       CPUS390XState *env = &cpu->env;
>       struct kvm_sregs sregs;
>       struct kvm_regs regs;
> +    struct kvm_fpu fpu;
>       int r;
>       int i;
>   
> @@ -229,6 +230,17 @@ int kvm_arch_put_registers(CPUState *cs, int level)
>           }
>       }
>   
> +    /* Floating point */
> +    for (i = 0; i < 16; i++) {
> +        fpu.fprs[i] = env->fregs[i].ll;
> +    }
> +    fpu.fpc = env->fpc;
> +
> +    r = kvm_vcpu_ioctl(cs, KVM_SET_FPU, &fpu);
> +    if (r < 0) {
> +        return r;
> +    }
> +
>       /* Do we need to save more than that? */
>       if (level == KVM_PUT_RUNTIME_STATE) {
>           return 0;
> @@ -296,6 +308,7 @@ int kvm_arch_get_registers(CPUState *cs)
>       CPUS390XState *env = &cpu->env;
>       struct kvm_sregs sregs;
>       struct kvm_regs regs;
> +    struct kvm_fpu fpu;
>       int i, r;
>   
>       /* get the PSW */
> @@ -336,6 +349,16 @@ int kvm_arch_get_registers(CPUState *cs)
>           }
>       }
>   
> +    /* Floating point */
> +    r = kvm_vcpu_ioctl(cs, KVM_GET_FPU, &fpu);
> +    if (r < 0) {
> +            return r;
> +        }

Broken indentation.


Alex

> +    for (i = 0; i < 16; i++) {
> +        env->fregs[i].ll = fpu.fprs[i];
> +    }
> +    env->fpc = fpu.fpc;
> +
>       /* The prefix */
>       if (cap_sync_regs && cs->kvm_run->kvm_valid_regs & KVM_SYNC_PREFIX) {
>           env->psa = cs->kvm_run->s.regs.prefix;