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| author | Eric Farman <farman@linux.ibm.com> | 2019-06-18 22:23:48 +0200 |
|---|---|---|
| committer | Cornelia Huck <cohuck@redhat.com> | 2019-06-21 14:12:19 +0200 |
| commit | 1d897e478da3db91593d86227854802102e2fcd3 (patch) | |
| tree | fca71d80651b7f6a957737e09b1ed6649d248d18 /drivers/s390/cio/vfio_ccw_cp.h | |
| parent | 01aa26c672c0eb771de4aaa2a8ccf6055778887b (diff) | |
| download | lwn-1d897e478da3db91593d86227854802102e2fcd3.tar.gz lwn-1d897e478da3db91593d86227854802102e2fcd3.zip | |
vfio-ccw: Move guest_cp storage into common struct
Rather than allocating/freeing a piece of memory every time
we try to figure out how long a CCW chain is, let's use a piece
of memory allocated for each device.
The io_mutex added with commit 4f76617378ee9 ("vfio-ccw: protect
the I/O region") is held for the duration of the VFIO_CCW_EVENT_IO_REQ
event that accesses/uses this space, so there should be no race
concerns with another CPU attempting an (unexpected) SSCH for the
same device.
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20190618202352.39702-2-farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'drivers/s390/cio/vfio_ccw_cp.h')
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_cp.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/s390/cio/vfio_ccw_cp.h b/drivers/s390/cio/vfio_ccw_cp.h index 3c20cd208da5..7cdc38049033 100644 --- a/drivers/s390/cio/vfio_ccw_cp.h +++ b/drivers/s390/cio/vfio_ccw_cp.h @@ -16,6 +16,12 @@ #include "orb.h" +/* + * Max length for ccw chain. + * XXX: Limit to 256, need to check more? + */ +#define CCWCHAIN_LEN_MAX 256 + /** * struct channel_program - manage information for channel program * @ccwchain_list: list head of ccwchains @@ -32,6 +38,7 @@ struct channel_program { union orb orb; struct device *mdev; bool initialized; + struct ccw1 *guest_cp; }; extern int cp_init(struct channel_program *cp, struct device *mdev, |