[v3,5/5] vfio-ccw: Update documentation for csch/hsch
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Message ID 7d977612c3f3152ffb950d77ae11b4b25c1e20c4.1562854091.git.alifm@linux.ibm.com
State New
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Series
  • Some vfio-ccw fixes
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Commit Message

Farhan Ali July 11, 2019, 2:28 p.m. UTC
We now support CLEAR SUBCHANNEL and HALT SUBCHANNEL
via ccw_cmd_region.

Fixes: d5afd5d135c8 ("vfio-ccw: add handling for async channel instructions")
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
---
 Documentation/s390/vfio-ccw.rst | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

Comments

Cornelia Huck July 12, 2019, 11:30 a.m. UTC | #1
On Thu, 11 Jul 2019 10:28:55 -0400
Farhan Ali <alifm@linux.ibm.com> wrote:

> We now support CLEAR SUBCHANNEL and HALT SUBCHANNEL
> via ccw_cmd_region.
> 
> Fixes: d5afd5d135c8 ("vfio-ccw: add handling for async channel instructions")
> Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
> ---
>  Documentation/s390/vfio-ccw.rst | 31 ++++++++++++++++++++++++++++---
>  1 file changed, 28 insertions(+), 3 deletions(-)

(...)

> +vfio-ccw cmd region
> +-------------------
> +
> +The vfio-ccw cmd region is used to accept asynchronous instructions
> +from userspace.
> +

Add :: and indent the structure so that we get proper formatting?

(Sorry about not noticing this last time; but I can add it while
applying if there are no other comments.)

> +#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.
> +
> +Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region.
> +

Otherwise,
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Farhan Ali July 12, 2019, 1:27 p.m. UTC | #2
On 07/12/2019 07:30 AM, Cornelia Huck wrote:
> On Thu, 11 Jul 2019 10:28:55 -0400
> Farhan Ali <alifm@linux.ibm.com> wrote:
> 
>> We now support CLEAR SUBCHANNEL and HALT SUBCHANNEL
>> via ccw_cmd_region.
>>
>> Fixes: d5afd5d135c8 ("vfio-ccw: add handling for async channel instructions")
>> Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
>> ---
>>   Documentation/s390/vfio-ccw.rst | 31 ++++++++++++++++++++++++++++---
>>   1 file changed, 28 insertions(+), 3 deletions(-)
> 
> (...)
> 
>> +vfio-ccw cmd region
>> +-------------------
>> +
>> +The vfio-ccw cmd region is used to accept asynchronous instructions
>> +from userspace.
>> +
> 
> Add :: and indent the structure so that we get proper formatting?
> 
> (Sorry about not noticing this last time; but I can add it while
> applying if there are no other comments.)

There is one other thing, I forgot to add a fixes tag to the first 
patch. If you don't mind fixing that as well that will be great :)

otherwise I could send a new round


> 
>> +#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.
>> +
>> +Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region.
>> +
> 
> Otherwise,
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 

Thanks for reviewing it

Thanks
Farhan
Eric Farman July 12, 2019, 1:28 p.m. UTC | #3
On 7/12/19 7:30 AM, Cornelia Huck wrote:
> On Thu, 11 Jul 2019 10:28:55 -0400
> Farhan Ali <alifm@linux.ibm.com> wrote:
> 
>> We now support CLEAR SUBCHANNEL and HALT SUBCHANNEL
>> via ccw_cmd_region.
>>
>> Fixes: d5afd5d135c8 ("vfio-ccw: add handling for async channel instructions")
>> Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
>> ---
>>  Documentation/s390/vfio-ccw.rst | 31 ++++++++++++++++++++++++++++---
>>  1 file changed, 28 insertions(+), 3 deletions(-)
> 
> (...)
> 
>> +vfio-ccw cmd region
>> +-------------------
>> +
>> +The vfio-ccw cmd region is used to accept asynchronous instructions
>> +from userspace.
>> +
> 
> Add :: and indent the structure so that we get proper formatting?
> 
> (Sorry about not noticing this last time; but I can add it while
> applying if there are no other comments.)
> 
>> +#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.
>> +
>> +Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region.
>> +
> 
> Otherwise,
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> 

Also good...

Reviewed-by: Eric Farman <farman@linux.ibm.com>

Patch
diff mbox series

diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst
index 1f6d0b5..be2af10 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.
+
+Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region.
+
 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 to issue HALT SUBCHANNEL and CLEAR SUBCHANNEL.
 
 vfio-ccw supports classic (command mode) channel I/O only. Transport
 mode (HPF) is not supported.