scsi: introduce hotplug() and hot_unplug() interfaces for SCSI bus

Add two interfaces hotplug() and hot_unplug() to scsi bus info.
The scsi bus can implement these two interfaces to signal the HBA driver
of guest kernel to add/remove the scsi device in question.

Signed-off-by: Sen Wang <senwang@linux.vnet.ibm.com>
Signed-off-by: Cong Meng <mc@linux.vnet.ibm.com>
[ Fixed braces and indentation - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
virtio-scsi: Implement hotplug support for virtio-scsi

Implement the hotplug() and hot_unplug() interfaces in virtio-scsi, by signal
the virtio_scsi.ko in guest kernel via event virtual queue.

The counterpart patch of virtio_scsi.ko will be sent soon in another thread.

Signed-off-by: Sen Wang <senwang@linux.vnet.ibm.com>
Signed-off-by: Cong Meng <mc@linux.vnet.ibm.com>
[ Add memset, fix LUN field, placate checkpatch - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
virtio-scsi: Report missed events

When an event is reported but no buffers are present in the event vq,
we can set a flag and report a dummy event as soon as one is added.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
megasas: Replace trace_megasas_dcmd_dump_frame()

trace_megasas_dcmd_dump_frame() takes 9 arguments, which is
rather much. Plus the trace infrastructure doesn't support
it.  As we can get the information via other means it's pointless
to have it in the driver, so rather use some proper trace
point here and remove the old one.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
megasas: fix misuse of scsi_req_abort

scsi_req_abort is for terminating a command with a non-zero status.
The ABORT task management function is invoked by scsi_req_cancel.
In fact, ABORTED_COMMAND is a sense key, not a SAM status code.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
lsi: use qdev_reset_all

By first resetting the devices, lsi_soft_reset will find the queue
already cleared so there is no need to do that forcibly (which may also
leak SCSIRequests, and/or worse due to dangling references to the
lsi_request in the hba_private field).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
lsi: introduce lsi_request_free

Split the common bits of lsi_request_cancelled and lsi_command_complete
out to a new function.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
lsi: avoid redundant tests of s->current != NULL

Simplify the code by checking against req->hba_private directly,
and asserting that it is non-NULL before a command is completed
or canceled.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-block: remove properties that are not relevant for passthrough

scsi-block is a passthrough device and does not allow customization
of vendor, product, removable, DPOFUA, block size or any other piece of
information.  Thus, drop DEFINE_SCSI_DISK_PROPERTIES() from the
list of qdev properties.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
cutils: add strpadcpy()

Signed-off-by: Yan Vugenfirer <yan@ravellosystems.com>
Signed-off-by: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: let the user customize vendor and product name

This patch adds two new properties vendor and product to SCSI disks.
These options let the user customize the inquiry data returned by the
disk.

Signed-off-by: Yan Vugenfirer <yan@ravellosystems.com>
Signed-off-by: Dmitry Fleytman <dmitry.fleytman@ravellosystems.com>
[ Use vendor and product property names, avoid "if" statements. - PB ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: make discard asynchronous

By making discard asynchronous, we can reuse all the error handling
code that is used for other commands.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: move all non-DMA commands to scsi_disk_emulate_command

We want to use separate SCSIReqOps for emulated commands needing an
allocated buffer vs. those that are zerocopy when the HBA supports
S/G lists.  Ensure that all of the former are in scsi_disk_emulate_command.

Commands that do not have any parameters are more similar to emulated
commands, so also move them, even if they do I/O.

Finally, MODE SELECT and MODE SELECT(10) are broken because we do not
yet support passing parameter data _to_ emulated commands, so disable
them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: split scsi-disk reqops

Only checks for present medium were still done in scsi_send_command
for emulated commands.  So move those to scsi_disk_emulate_command
and return different SCSIReqOps depending on the kind of command.

Checks for present medium can be done unconditionally for the
scsi_disk_dma_reqops case.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: separate read_data/write_data implementation for emulate_reqops

The previous patch only separated the send_command callback.
Use different implementations also for read_data and write_data.
The latter is still unreachable, so it aborts for now.

read_data passes the data buffer that was prepared and completes
the command.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: support emulated TO_DEV requests

This adds the implementation of write_data for the emulated
command case.  The first time through it asks for more data,
the second time it finishes the processing of the command.

MODE SELECT and MODE SELECT(10) can now be re-enabled, but they
will not do much.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: adjust offsets in MODE SENSE by 2

This will make offsets the same when implementing MODE SELECT.  This is
because MODE SELECT has to deal with both 2-byte and 4-byte headers.
Unfortunately, this means that the offsets are now off by two compared
to the descriptions in the SCSI specs, which include the header.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: fix changeable values for MODE_PAGE_R_W_ERROR

The changeable values were not all-zeros for this mode page, fix it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: parse MODE SELECT commands and parameters

This adds the bulk of the parsing code for MODE SELECT, including
breaking out changes to different mode pages, and checking that only
changeable values are modified.

In order to report errors correctly two passes are made through the
parameters; the first only looks for errors, the second actually
applies the changes to the mode page.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk: support toggling the write cache

Finally, this uses the "plumbing" in the previous patch to
add support for toggling the WCE bit of the caching mode page.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>