Re: [PATCH v7 13/14] Documentation: KVM: s390: Describe KVM_S390_MEMOP_F_CMPXCHG

Janosch Frank
2023-02-07T15:56:20Z

On 2/6/23 17:46, Janis Schoetterl-Glausch wrote:
> Describe the semantics of the new KVM_S390_MEMOP_F_CMPXCHG flag for
> absolute vm write memops which allows user space to perform (storage key
> checked) cmpxchg operations on guest memory.
>
> Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
> ---
> Documentation/virt/kvm/api.rst | 29 ++++++++++++++++++++++++++---
> 1 file changed, 26 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
> index 0a67cb738013..d09d7223c2a6 100644
> --- a/Documentation/virt/kvm/api.rst
> +++ b/Documentation/virt/kvm/api.rst
> @@ -3736,7 +3736,8 @@ The fields in each entry are defined as follows:
> :Parameters: struct kvm_s390_mem_op (in)
> :Returns: = 0 on success,
> < 0 on generic error (e.g. -EFAULT or -ENOMEM),
> - > 0 if an exception occurred while walking the page tables
> + 16 bit program exception code if the access causes such an exception,
> + other code > 0xffff with special meaning.
>

The 0xffff part is rebase damage from an old patch, I've discussed it
off list and will remove that line when picking since I see no other
reason for a re-spin.

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>