This patch adds support for bdrv_create. This allows e.g.
to use qemu-img to convert from any supported device to
an iscsi backed storage as destination.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

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

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

Various header files rely on qemu-char.h including qemu-config.h or
main-loop.h, but they really do not need qemu-char.h at all (particularly
interesting is the case of the block layer!).  Clean this up, and also
add missing inclusions of qemu-char.h itself.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Without any complex checks we can't assume that an
iscsi target is initialized to zero.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If the connection is interrupted before the first login is successfully
completed qemu-kvm is waiting forever in qemu_aio_wait().

This is fixed by performing an sync login to the target. If the
connection breaks after the first successful login errors are
handled internally by libiscsi.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If an invalid URL is specified iscsi_get_error(iscsi) is called
with iscsi == NULL.
Signed-off-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Now that AIOPool no longer keeps a freelist, it isn't really a "pool"
anymore.  Rename it to AIOCBInfo and make it const since it no longer
needs to be modified.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Block drivers should ignore BDRV_O_CACHE_WB in .bdrv_open flags,
and in the bs->open_flags.

This patch removes the code, leaving the behaviour behind as if
BDRV_O_CACHE_WB was set.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We no longer need to explicitely call qemu_notify_event() any more
since this is now done automatically any time the filehandles we listen
to change.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We need to support SG_IO from the synchronous iscsi_ioctl() since
scsi-block uses this to do an INQ to the device to discover its properties
This patch makes scsi-block work with iscsi.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The number of blocks of the device is used to compute the device size
in bdrv_getlength()/iscsi_getlength().
For MMC devices, the ReturnedLogicalBlockAddress in the READCAPACITY10
has a special meaning when it is 0.
In this case it does not mean that LBA 0 is the last accessible LBA,
and thus the device has 1 readable block, but instead it means that the
disc is blank and there are no readable blocks.

This change ensures that when the iSCSI LUN is loaded with a blank
DVD-R disk or similar that bdrv_getlength() will return the correct
size of the device as 0 bytes.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>

This patch fixes two main issues with block/iscsi.c:

1) iscsi_task_mgmt_abort_task_async calls iscsi_scsi_task_cancel which
was also directly called in iscsi_aio_cancel

2) a race between task completion and task abortion could happen cause
the scsi_free_scsi_task were done before iscsi_schedule_bh has finished.
To fix this, all the freeing of IscsiTasks and releasing of the AIOCBs
is centralized in iscsi_bh_cb, independent of whether the SCSI command
has completed or was cancelled.

3) iscsi_aio_cancel was not synchronously waiting for the end of the
command.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

It is always used with the same callback, remove the argument.  And
its return value is never used, assume allocation succeeds.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Put these functions at the beginning, to avoid forward references
in the next patches.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This reverts commit 64e69e80.  The commit
returned immediately from iscsi_aio_cancel, risking corruption in case the
following happens:

    guest                  qemu                 target
  =========================================================================
    send write 1 -------->
                           send write 1 -------->
    cancel write 1 ------>
                           cancel write 1 ------>
       <------------------ cancellation processed
    send write 2 -------->
                           send write 2 -------->
                               <---------------- completed write 2
       <------------------ completed write 2
                               <---------------- completed write 1
                               <---------------- cancellation not done

Here, the guest would see write 2 superseding write 1, when in fact the
outcome could have been the opposite.  The right behavior is to return
only after the target says whether the cancellation was done or not, and
it will be implemented by the next three patches.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Signed-off-by: NStefan Priebe <s.priebe@profihost.ag>
Acked-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch updates the iscsi layer to automatically pick a 'unique'
initiator-name based on the name of the vm in case the user has not set
an explicit iqn-name to use.

Create a new function qemu_get_vm_name() that returns the name of the VM,
if specified.

This way we can thus create default names to use as the initiator name
based on the guest session.

If the VM is not named via the '-name' command line argument, the iscsi
initiator-name used wiull simply be

    iqn.2008-11.org.linux-kvm

If a name for the VM was specified with the '-name' option, iscsi will
use a default initiatorname of

    iqn.2008-11.org.linux-kvm:<name>

These names are just the default iscsi initiator name that qemu will
generate/use only when the user has not set an explicit initiator name
via the commandlines or config files.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>

Merge the occurrences of the "iqn.2008-11.org.linux-kvm" string
to avoid duplication.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The argument of iscsi_create_context is never freed by libiscsi,
which in fact calls strdup on it.  Avoid a leak.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If the device we open is a SMC or SSC device, then force the use of sg. We
dont have any medium changer or tape emulation so only passthrough via
real sg or scsi-generic via iscsi would work anyway.

Forcing sg also makes qemu skip trying to read from the device to guess
the image format by reading from the device (find_image_format()).
SMC devices do not implement READ6/10/12/16 so it is not possible to
read from them (SSC have different CDBs).

With this patch I can successfully manage a SMC device wiht iscsi in
passthrough mode.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
[Added TYPE_TAPE handling - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Update iscsi to allow passthrough of SG_IO scsi commands when the iscsi
device is forced to be scsi-generic.

Implement both bdrv_ioctl() and bdrv_aio_ioctl() in the iscsi backend,
emulate the SG_IO ioctl and pass the SCSI commands across to the
iscsi target.

This allows end-to-end passthrough of SCSI all the way from the guest,
to qemu, via scsi-generic, then libiscsi all the way to the iscsi target.

To activate this you need to specify that the iscsi lun should be treated
as a scsi-generic device.

Example:
    -device lsi -device scsi-generic,drive=MyISCSI \
    -drive file=iscsi://10.1.1.125/iqn.ronnie.test/1,if=none,id=MyISCSI

Note, you can currently not boot a qemu guest from a scsi device.

Note,
This only works when the host is linux, since the emulation relies on
definitions of SG_IO from the scsi-generic implementation in the
linux kernel.
It should be fairly easy to re-implement some structures similar enough
for non-linux hosts to do the same style of passthrough via a fake
scsi generic layer and libiscsi if need be.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

It now allows specifying offset within qiov to start from and
amount of bytes to copy.  Actual implementation is just a call
to iov_to_buf().
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

This allows using LUNs bigger than 2TB.  Keep using READ10 for other
device types such as MMC.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>

Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>

This is needed to avoid READ CAPACITY(16) for MMC devices.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

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

Call qemu_notify_event() after updating events.  Otherwise, If we add
an event for -is-writeable but the socket is already writeable there
may be a delay before the event callback is actually triggered.

Those delays would in particular hurt performance during BIOS boot and
when the GRUB bootloader reads the kernel and initrd.

But first call out to the socket write functions directly, and only set up
the write event if the socket is full.  This will happen very rarely and
this improves performance.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>

Update the configure test for libiscsi support to detect version 1.3
or later.  Version 1.3 of libiscsi provides both READCAPACITY16 as well
as UNMAP commands.

Update the iscsi block layer to use READCAPACITY16 to detect the size of
the LUN instead of READCAPACITY10. This allows support for LUNs larger
than 2TB.

Update to implement bdrv_aio_discard() using the UNMAP command.
This allows us to use thin-provisioned LUNs from TGTD and other iSCSI
targets that support thin-provisioning.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
[squashed in subsequent patch from Ronnie to fix off-by-one in LBA count]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Both unused after the previous patch.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch adds configuration variables for iSCSI to set
initiator-name to use when logging in to the target,
which type of header-digest to negotiate with the target
and username and password for CHAP authentication.

This allows specifying a initiator-name either from the command line
-iscsi initiator-name=iqn.2004-01.com.example:test
or from a configuration file included with -readconfig
    [iscsi]
      initiator-name = iqn.2004-01.com.example:test
      header-digest = CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
      user = CHAP username
      password = CHAP password

If you use several different targets, you can also configure this on a per
target basis by using a group name:
    [iscsi "iqn.target.name"]
    ...

The configuration file can be read using -readconfig.
Example :
qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.ronnie.test/1
 -readconfig iscsi.conf
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This provides built-in support for iSCSI to QEMU.

This has the advantage that the iSCSI devices need not be made visible to the host, which is useful if you have very many virtual machines and very many iscsi devices.
It also has the benefit that non-root users of QEMU can access iSCSI devices across the network without requiring root privilege on the host.

This driver interfaces with the multiplatform posix library for iscsi initiator/client access to iscsi devices hosted at
    git://github.com/sahlberg/libiscsi.git

The patch adds the driver to interface with the iscsi library.
It also updated the configure script to
* by default, probe is libiscsi is available and if so, build
  qemu against libiscsi.
* --enable-libiscsi
  Force a build against libiscsi. If libiscsi is not available
  the build will fail.
* --disable-libiscsi
  Do not link against libiscsi, even if it is available.

When linked with libiscsi, qemu gains support to access iscsi resources such as disks and cdrom directly, without having to make the devices visible to the host.

You can specify devices using a iscsi url of the form :
iscsi://[<username>[:<password>@]]<host>[:<port]/<target-iqn-name>/<lun>
When using authentication, the password can optionally be set with
LIBISCSI_CHAP_PASSWORD="password" to avoid it showing up in the process list
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>