Re: [PATCH v3 10/10] KVM: s390: Fix cleanup in kvm_s390_pv_create_cpu()

[Steffen Eiden <seiden@linux.ibm.com>]

On Mon, Jul 27, 2026 at 05:02:54PM +0200, Claudio Imbrenda wrote:
> If creating a protected vCPU in kvm_s390_pv_create_cpu() fails,
> kvm_s390_pv_destroy_cpu() was called, which checks whether the vCPU has
> a PV handle and exits doing nothing otherwise. At that point, due to
> not having created the protected vCPU, the PV handle will not be set,
> and kvm_s390_pv_destroy_cpu() will do nothing, thus leaking the
> allocated memory.
> 
> Fix by factoring out the code to free and reset a PV vCPU; call it from
> kvm_s390_pv_destroy_cpu() and kvm_s390_pv_create_cpu().
> 
> Fixes: d4074324b07a ("KVM: s390: pv: avoid double free of sida page")
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>

> ---
>  arch/s390/kvm/pv.c | 41 +++++++++++++++++++++--------------------
>  1 file changed, 21 insertions(+), 20 deletions(-)
> 
> diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
> index dc204b521052..b02e0159d3cd 100644
> --- a/arch/s390/kvm/pv.c
> +++ b/arch/s390/kvm/pv.c
...
>  int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
>  {
>
...

> -	return cc ? EIO : 0;
> +	return cc ? -EIO : 0;

maye add a comment that you fixed this return value as well.

	Steffen