Explicitly specify the valid ranges for size and ar, and reword buf requirements a bit. Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx> --- 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@xxxxxxxxxx>) --- 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. -- 2.20.1