Re: [PATCH] KVM: s390: improve documentation for S390_MEM_OP

[Thomas Huth <thuth@redhat.com>]

On 29/08/2019 14.47, Cornelia Huck wrote:
> Explicitly specify the valid ranges for size and ar, and reword
> buf requirements a bit.
> 
> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> ---
> supposed to go on top of "KVM: s390: Test for bad access register and
> size at the start of S390_MEM_OP" (<20190829122517.31042-1-thuth@redhat.com>)
> ---
>  Documentation/virt/kvm/api.txt | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt
> index 2d067767b617..76c9d6fdbfdb 100644
> --- a/Documentation/virt/kvm/api.txt
> +++ b/Documentation/virt/kvm/api.txt
> @@ -3079,12 +3079,14 @@ This exception is also raised directly at the corresponding VCPU if the
>  flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field.
>  
>  The start address of the memory region has to be specified in the "gaddr"
> -field, and the length of the region in the "size" field. "buf" is the buffer
> -supplied by the userspace application where the read data should be written
> -to for KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written
> -is stored for a KVM_S390_MEMOP_LOGICAL_WRITE. "buf" is unused and can be NULL
> -when KVM_S390_MEMOP_F_CHECK_ONLY is specified. "ar" designates the access
> -register number to be used.
> +field, and the length of the region in the "size" field (which must not
> +be 0). The maximum value for "size" can be obtained by checking the
> +KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the
> +userspace application where the read data should be written to for
> +KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is
> +stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY
> +is specified, "buf" is unused and can be NULL. "ar" designates the access
> +register number to be used; the valid range is 0..15.
>  
>  The "reserved" field is meant for future extensions. It is not used by
>  KVM with the currently defined set of flags.
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>