Re: [PATCH 3/4] KVM: s390: pv: Fix rc/rrc offset for PVM_DUMP

On Tue, 11 Aug 2026 17:37:37 +0200
Christian Borntraeger <[email protected]> wrote:

> The rc/rrc value is copied to the cmd location of the cmd in the kvm_pv_cmd
> structure. Fix the offset.
> 
> Fixes: 8aba09588d2a ("KVM: s390: Add CPU dump functionality")
> Cc: [email protected]
> Signed-off-by: Christian Borntraeger <[email protected]>

Reviewed-by: Claudio Imbrenda <[email protected]>

the documentation for KVM_S390_PV_CPU_COMMAND looks wrong, we should
fix that at some point.

> ---
>  arch/s390/kvm/kvm-s390.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index ea9bfb32d0f2..f3814dd60184 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -5734,7 +5734,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
>  		r = kvm_s390_handle_pv_vcpu_dump(vcpu, &cmd);
>  
>  		/* Always copy over UV rc / rrc data */
> -		if (copy_to_user((__u8 __user *)argp, &cmd.rc,
> +		if (copy_to_user(argp + offsetof(struct kvm_pv_cmd, rc), &cmd.rc,
>  				 sizeof(cmd.rc) + sizeof(cmd.rrc)))
>  			r = -EFAULT;
>  		break;