From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:28978 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726149AbfGIMsI (ORCPT ); Tue, 9 Jul 2019 08:48:08 -0400 Subject: Re: [RFC v2 5/5] vfio-ccw: Update documentation for csch/hsch References: <20190709121445.1d7bf8ed.cohuck@redhat.com> From: Farhan Ali Message-ID: <58ece8ce-a155-3353-71f1-26e242db5c55@linux.ibm.com> Date: Tue, 9 Jul 2019 08:47:38 -0400 MIME-Version: 1.0 In-Reply-To: <20190709121445.1d7bf8ed.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Cornelia Huck Cc: farman@linux.ibm.com, pasic@linux.ibm.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org On 07/09/2019 06:14 AM, Cornelia Huck wrote: > On Mon, 8 Jul 2019 16:10:38 -0400 > Farhan Ali wrote: > >> We now support CLEAR SUBCHANNEL and HALT SUBCHANNEL >> via ccw_cmd_region. >> > > Thanks, I forgot about this. > > Fixes: d5afd5d135c8 ("vfio-ccw: add handling for async channel instructions") > I don't know if this warranted a fixes tag but I will add it. >> Signed-off-by: Farhan Ali >> --- >> Documentation/s390/vfio-ccw.rst | 31 ++++++++++++++++++++++++++++--- >> 1 file changed, 28 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst >> index 1f6d0b5..40e4110 100644 >> --- a/Documentation/s390/vfio-ccw.rst >> +++ b/Documentation/s390/vfio-ccw.rst >> @@ -180,6 +180,13 @@ The process of how these work together. >> add it to an iommu_group and a vfio_group. Then we could pass through >> the mdev to a guest. >> >> + >> +VFIO-CCW Regions >> +---------------- >> + >> +The vfio-ccw driver exposes MMIO regions to accept requests from and return >> +results to userspace. >> + >> vfio-ccw I/O region >> ------------------- >> >> @@ -205,6 +212,25 @@ irb_area stores the I/O result. >> >> ret_code stores a return code for each access of the region. >> >> +This region is always available. >> + >> +vfio-ccw cmd region >> +------------------- >> + >> +The vfio-ccw cmd region is used to accept asynchronous instructions >> +from userspace. >> + >> +#define VFIO_CCW_ASYNC_CMD_HSCH (1 << 0) >> +#define VFIO_CCW_ASYNC_CMD_CSCH (1 << 1) >> +struct ccw_cmd_region { >> + __u32 command; >> + __u32 ret_code; >> +} __packed; >> + >> +This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD. >> + >> +CLEAR SUBCHANNEL and HALT SUBCHANNEL currently uses this region. > > "Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region". ? > This sounds better to me :) >> + >> vfio-ccw operation details >> -------------------------- >> >> @@ -306,9 +332,8 @@ Together with the corresponding work in QEMU, we can bring the passed >> through DASD/ECKD device online in a guest now and use it as a block >> device. >> >> -While the current code allows the guest to start channel programs via >> -START SUBCHANNEL, support for HALT SUBCHANNEL or CLEAR SUBCHANNEL is >> -not yet implemented. >> +The current code allows the guest to start channel programs via >> +START SUBCHANNEL, and supports HALT SUBCHANNEL or CLEAR SUBCHANNEL. > > "The current code allows the guest to start channel programs via START > SUBCHANNEL, and to issue HALT SUBCHANNEL and CLEAR SUBCHANNEL." ? > Same. I will update with the changes you requested. >> >> vfio-ccw supports classic (command mode) channel I/O only. Transport >> mode (HPF) is not supported. > > Thanks for taking a look. Thanks Farhan