From: Cornelia Huck <cohuck@redhat.com>
To: Heiko Carstens <heiko.carstens@de.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Farman <farman@linux.ibm.com>,
Halil Pasic <pasic@linux.ibm.com>,
linux-s390@vger.kernel.org, kvm@vger.kernel.org,
Cornelia Huck <cohuck@redhat.com>
Subject: [PULL v2 02/10] vfio-ccw: document possible errors
Date: Wed, 3 Jun 2020 13:27:08 +0200 [thread overview]
Message-ID: <20200603112716.332801-3-cohuck@redhat.com> (raw)
In-Reply-To: <20200603112716.332801-1-cohuck@redhat.com>
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 <cohuck@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
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
next prev parent reply other threads:[~2020-06-03 11:27 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-03 11:27 [PULL v2 00/10] vfio-ccw patches for 5.8 Cornelia Huck
2020-06-03 11:27 ` [PULL v2 01/10] vfio-ccw: Enable transparent CCW IPL from DASD Cornelia Huck
2020-06-03 11:27 ` Cornelia Huck [this message]
2020-06-03 11:27 ` [PULL v2 03/10] vfio-ccw: Introduce new helper functions to free/destroy regions Cornelia Huck
2020-06-03 11:27 ` [PULL v2 04/10] vfio-ccw: Register a chp_event callback for vfio-ccw Cornelia Huck
2020-06-03 11:27 ` [PULL v2 05/10] vfio-ccw: Refactor the unregister of the async regions Cornelia Huck
2020-06-03 11:27 ` [PULL v2 06/10] vfio-ccw: Introduce a new schib region Cornelia Huck
2020-06-03 11:27 ` [PULL v2 07/10] vfio-ccw: Refactor IRQ handlers Cornelia Huck
2020-06-03 11:27 ` [PULL v2 08/10] vfio-ccw: Introduce a new CRW region Cornelia Huck
2020-06-03 11:27 ` [PULL v2 09/10] vfio-ccw: Wire up the CRW irq and " Cornelia Huck
2020-06-03 11:27 ` [PULL v2 10/10] vfio-ccw: Add trace for CRW event Cornelia Huck
2020-06-04 11:14 ` [PULL v2 00/10] vfio-ccw patches for 5.8 Vasily Gorbik
2020-06-04 11:20 ` [PATCH] vfio-ccw: make vfio_ccw_regops variables declarations static Vasily Gorbik
2020-06-04 11:27 ` Cornelia Huck
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