From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:35406 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2389628AbgEYJld (ORCPT ); Mon, 25 May 2020 05:41:33 -0400 From: Cornelia Huck Subject: [PULL 02/10] vfio-ccw: document possible errors Date: Mon, 25 May 2020 11:41:07 +0200 Message-Id: <20200525094115.222299-3-cohuck@redhat.com> In-Reply-To: <20200525094115.222299-1-cohuck@redhat.com> References: <20200525094115.222299-1-cohuck@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Heiko Carstens , Vasily Gorbik , Christian Borntraeger Cc: Eric Farman , Halil Pasic , linux-s390@vger.kernel.org, kvm@vger.kernel.org, Cornelia Huck Interacting with the I/O and the async regions can yield a number of errors, which had been undocumented so far. These are part of the api, so remedy that. Signed-off-by: Cornelia Huck Reviewed-by: Eric Farman Message-Id: <20200407111605.1795-1-cohuck@redhat.com> --- Documentation/s390/vfio-ccw.rst | 56 +++++++++++++++++++++++++++++++-- 1 file changed, 54 insertions(+), 2 deletions(-) diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst index 23e7d136f8b4..3a946fd45562 100644 --- a/Documentation/s390/vfio-ccw.rst +++ b/Documentation/s390/vfio-ccw.rst @@ -204,15 +204,44 @@ definition of the region is:: __u32 ret_code; } __packed; +This region is always available. + While starting an I/O request, orb_area should be filled with the guest ORB, and scsw_area should be filled with the SCSW of the Virtual Subchannel. irb_area stores the I/O result. -ret_code stores a return code for each access of the region. +ret_code stores a return code for each access of the region. The following +values may occur: + +``0`` + The operation was successful. + +``-EOPNOTSUPP`` + The orb specified transport mode or an unidentified IDAW format, or the + scsw specified a function other than the start function. + +``-EIO`` + A request was issued while the device was not in a state ready to accept + requests, or an internal error occurred. + +``-EBUSY`` + The subchannel was status pending or busy, or a request is already active. + +``-EAGAIN`` + A request was being processed, and the caller should retry. + +``-EACCES`` + The channel path(s) used for the I/O were found to be not operational. + +``-ENODEV`` + The device was found to be not operational. + +``-EINVAL`` + The orb specified a chain longer than 255 ccws, or an internal error + occurred. -This region is always available. vfio-ccw cmd region ------------------- @@ -231,6 +260,29 @@ This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD. Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region. +command specifies the command to be issued; ret_code stores a return code +for each access of the region. The following values may occur: + +``0`` + The operation was successful. + +``-ENODEV`` + The device was found to be not operational. + +``-EINVAL`` + A command other than halt or clear was specified. + +``-EIO`` + A request was issued while the device was not in a state ready to accept + requests. + +``-EAGAIN`` + A request was being processed, and the caller should retry. + +``-EBUSY`` + The subchannel was status pending or busy while processing a halt request. + + vfio-ccw operation details -------------------------- -- 2.25.4