The request restart mechanism is generic and could be reused for
scsi-generic.  In the meanwhile, pushing it to SCSIDevice avoids
that scsi_dma_restart_bh looks at SCSIGenericReqs when working on
a scsi-block device.

The code is the same that is already in hw/scsi-disk.c, with
the type flags replaced by req->cmd.mode and a more generic way to
requeue SCSI_XFER_NONE commands.

I also added a missing call to qemu_del_vm_change_state_handler.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Otherwise, if cancellation is "faked" by the AIO layer and goes
through qemu_aio_flush, the whole request is completed synchronously
during scsi_req_cancel.

Using the enqueued flag would work here, but not in the next patches,
so I'm introducing a new io_canceled flag.  That's because scsi_req_data
is a synchronous callback and the enqueued flag might be reset by the
time it returns.  scsi-disk cannot unref the request until after calling
scsi_req_data.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This will let scsi-block choose between passthrough and emulation.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Also delete a stale occurrence of SCSIReqOps inside SCSIDeviceInfo.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The field is only in scsi-disk for now.  Moving it up to SCSIDevice makes
it easier to reuse the scsi-generic reqops elsewhere.

At the same time, make scsi-generic get max_lba from snooped READ CAPACITY
commands as well.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This also requires little more than adding the new argument to
scsi_device_find, and the qdev property.  All devices by default
end up on channel 0.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This only requires changes in two places: in SCSIBus, we need to look
for a free LUN if somebody creates a device with a pre-existing scsi-id
but the default LUN (-1, meaning "search for a free spot"); in vSCSI,
we need to actually parse the LUN according to the SCSI spec.

For vSCSI, max_target/max_lun are set according to the logical unit
addressing format in SAM.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Change the devs array into a linked list, and add a scsi_device_find
function to navigate the children list instead.  This lets the SCSI
bus use more complex addressing, and HBAs can talk to the correct device
when there are multiple LUNs per target.

scsi_device_find may return another LUN on the same target if none is
found that matches exactly.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Building on the previous patch, this one adds a media change callback
to scsi-disk.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Reporting media change events via unit attention sense codes requires
a small state machine: first report "NO MEDIUM", then report "MEDIUM MAY
HAVE CHANGED".  Unfortunately there is no good hooking point for the
device to notice that its pending unit attention condition has been
reported.  This patch reworks the generic machinery to add one.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

It's convenience stuff for block device models, so block.h isn't the
ideal home either, but better than block_int.h.

Permits moving some #include "block_int.h" from device model .h into
.c.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Don't fail when tray is already open.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Unit attention conditions override any sense data the device already
has.  Their signaling and clearing is handled entirely by the SCSIBus
code, and they are completely transparent to the SCSIDevices.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Also introduce the first occurrence of "independent" SCSIReqOps,
to handle invalid commands in common code.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This will let SCSIBus detect requests sent to an invalid LUN, and
handle them itself.  However, there will be still support for only one
LUN per target
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This struct is currently unnamed.  Give it a name and use it
explicitly to decouple (some parts of) CDB parsing from
SCSIRequest.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Right now the CDB is not passed to the SCSIBus until scsi_req_enqueue.
Passing it to scsi_req_new will let scsi_req_new dispatch common requests
through different reqops.

Moving the memcpy to scsi_req_new is a hack that will go away as
soon as scsi_req_new will also take care of the parsing.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This will let allow requests to be dispatched through different callbacks,
either common or per-device.

This patch adjusts the API, the next one will move members to SCSIReqOps.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

With this patch, sense data is stored in the generic data structures
for SCSI devices and requests.  The SCSI layer takes care of storing
sense data in the SCSIDevice for the subsequent REQUEST SENSE command.

At the same time, get_sense is removed and scsi_req_get_sense can use
an entirely generic implementation.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

A small improvement in the SCSI request API.  Pass the status
at the time the request is completed, so that we can assert that
no request is completed twice.  This would have detected the
problem fixed in the previous patch.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

'tag' is just an abstraction to identify the command
from the driver. So we should make that explicit by
replacing 'tag' with a driver-defined pointer 'hba_private'.
This saves the lookup for driver handling several commands
in parallel.
'tag' is still being kept for tracing purposes.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>

The return value is unused anyway.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

The get_sense callback copies existing sense information into
the provided buffer. This is required if sense information
should be transferred together with the command response.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

... and remove some SCSIDevice variables or fields that now become unused.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the common part of scsi-disk.c and scsi-generic.c to the SCSI layer.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

The SCSI spec has a quite detailed list of sense codes available.
It even mandates the use of specific ones for some failure cases.
The current implementation just has one type of generic error
which is actually a violation of the spec in certain cases.
This patch introduces various predefined sense codes to have the
sense code reporting more in line with the spec.

On top of Hannes's patch I fixed the reply to REQUEST SENSE commands
with DESC=0 and a small (<18) length.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

This is for when the request must be dropped in the void,
but still memory should be freed.  To this end, the devices
register a second callback in SCSIBusOps.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

This covers the case of canceling a request's I/O and still
completing it.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

The code for canceling requests upon reset is already the same.  Clean
it up and move it to scsi-bus.c.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Currently the SCSIRequest structure is abstracted away and cannot accessed
directly from the driver. This requires the handler to do a lookup on
an abstract 'tag' which identifies the SCSIRequest structure.

With this patch the SCSIRequest structure is exposed to the driver. This
allows use to use it directly as an argument to the SCSIDeviceInfo
callback functions and remove the lookup.

A new callback function 'alloc_req' is introduced matching 'free
req'; unref'ing to free up resources after use is moved into the
scsi_command_complete callbacks.

This temporarily introduces a leak of requests that are cancelled,
when they are removed from the queue and not from the driver.  This
is fixed later by introducing scsi_req_cancel.  That patch in turn
depends on this one, because the argument to scsi_req_cancel is a
SCSIRequest.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

With the next patch, a device may hold SCSIRequest for an indefinite
time.  Split a rather big patch, and protect against access errors,
by reference counting them.

There is some ugliness in scsi_send_command implementation due to
the need to unref the request when it fails.  This will go away
with the next patches, which move the unref'ing to the devices.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>

There are more operations than a SCSI bus can handle, besides completing
commands.  One example, which this series will introduce, is cleaning up
after a request is cancelled.

More long term, a "SCSI bus" can represent the LUNs attached to a
target; in this case, while all commands will ultimately reach a logical
unit, it is the target who is in charge of answering REPORT LUNs.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>