Re: [PATCH 2/4] KVM: s390: fix wrong lookup of VCPUs by array index

[Christian Borntraeger <borntraeger@de.ibm.com>]

Sigh.
Seems that my mail script got confused by the # after stable. So please
strip down the cc list.


On 11/19/2015 09:37 AM, Christian Borntraeger wrote:
> From: David Hildenbrand <dahi@linux.vnet.ibm.com>
> 
> For now, VCPUs were always created sequentially with incrementing
> VCPU ids. Therefore, the index in the VCPUs array matched the id.
> 
> As sequential creation might change with cpu hotplug, let's use
> the correct lookup function to find a VCPU by id, not array index.
> 
> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> [split stable/non-stable parts]
> Cc: stable@vger.kernel.org # c3853a8: KVM: Provide function for VCPU lookup by id
> ---
>  arch/s390/kvm/sigp.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
> index da690b6..081dbd0 100644
> --- a/arch/s390/kvm/sigp.c
> +++ b/arch/s390/kvm/sigp.c
> @@ -291,12 +291,8 @@ static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
>  			   u16 cpu_addr, u32 parameter, u64 *status_reg)
>  {
>  	int rc;
> -	struct kvm_vcpu *dst_vcpu;
> +	struct kvm_vcpu *dst_vcpu = kvm_lookup_vcpu(vcpu->kvm, cpu_addr);
> 
> -	if (cpu_addr >= KVM_MAX_VCPUS)
> -		return SIGP_CC_NOT_OPERATIONAL;
> -
> -	dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
>  	if (!dst_vcpu)
>  		return SIGP_CC_NOT_OPERATIONAL;
> 
> @@ -478,7 +474,7 @@ int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
>  	trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
> 
>  	if (order_code = SIGP_EXTERNAL_CALL) {
> -		dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
> +		dest_vcpu = kvm_lookup_vcpu(vcpu->kvm, cpu_addr);
>  		BUG_ON(dest_vcpu = NULL);
> 
>  		kvm_s390_vcpu_wakeup(dest_vcpu);
>