kvm: Query KVM for available memory slots

KVM reports the number of available memory slots (KVM_CAP_NR_MEMSLOTS)
using the extension interface.  Both x86 and s390 implement this, ARM
and powerpc do not yet enable it.  Convert the static slots array to
be dynamically allocated, supporting more slots when available.
Default to 32 when KVM_CAP_NR_MEMSLOTS is not implemented.  The
motivation for this change is to support more assigned devices, where
memory mapped PCI MMIO BARs typically take one slot each.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu: mempath: prefault pages manually (v4)

v4: s/fail/failed/  (Peter Maydell)

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
xhci: Add a few missing checks for disconnected devices

One of the reworks of qemu's usb core made changes to usb-port's disconnect
handling. Now ports with a device will always have a non 0 dev member, but
if the device is not attached (which is possible with usb redirection),
dev->attached will be 0.

So supplement all checks for dev to also check dev->attached, and add an
extra check in a path where a device check was completely missing.

This fixes various crashes (asserts triggering) I've been seeing when xhci
attached usb devices get disconnected at the wrong time.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
xhci: add support for suspend/resume

The OS can ask the xhci controller to save and restore its
internal state, which is used by the OS when the system is
suspended and resumed.

This patch handles writes to the save + restore bits in the
command register.  Only thing it does is updating the
restore error bit in the status register to signal an error
on restore.  The guest OS should do a full reinitialization
after resume then.

This is the minimal patch which gets S3 going with xhci.
Implementing full save/restore support is TBD.

https://bugzilla.redhat.com/show_bug.cgi?id=1012365

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
scsi: Add 2 new sense codes needed by uas

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
uas: Only use report iu-s for task_mgmt status reporting

Regular scsi cmds should always report their status using a sense-iu, using
the sense code to report any errors.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
uas: Fix / cleanup usb_uas_task error handling

-The correct error if we cannot find the dev is INCORRECT_LUN rather then
 INVALID_INFO_UNIT
-Move the device not found check to the top so we only need to do it once
-Remove the dev->lun != lun checks, dev is returned by scsi_device_find
 which searches by lun, so this will never trigger

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
uas: Streams are numbered 1-y, rather then 0-x

It is easier to simply make the arrays one larger, rather then
substracting one everywhere.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
uas: Bounds check tags when using streams

Disallow the guest to cause us to address the data3 and status3 arrays
out of bounds.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
uas: Fix response iu struct definition

This patch mirrors a patch to the Linux uas kernel driver which I've just
submitted. It looks like the qemu uas struct definitions were taken from
the Linux kernel driver, and have inherited the same mistake.

Besides fixing the response iu struct, the patch also drops the add_info
parameter from the usb_uas_queue_response() function, it is always 0 anyways,
and expressing 3 zero-bytes as a function argument is a bit hard.

Below is the long explanation for this change taken from the kernel commit:

The response iu struct before this patch has a size of 7 bytes, which is weird
since all other iu-s are explictly padded to a multiple of 4 bytes.

Submitting a 7 byte bulk transfer to the status endpoint of a real uasp device
when expecting a response iu results in an USB babble error, as the device
actually sends 8 bytes.

Up on closer reading of the UAS spec:
http://www.t10.org/cgi-bin/ac.pl?t=f&f=uas2r00.pdf

The reason for this becomes clear, the 2 entries in "Table 17 — RESPONSE IU"
are numbered 4 and 6, looking at other iu definitions in the spec, esp.
multi-byte fields, this indicates that the ADDITIONAL RESPONSE INFORMATION
field is not a 2 byte field as one might assume at a first look, but is
a multi-byte field containing 3 bytes.

This also aligns with the SCSI Architecture Model 4 spec, which UAS is based
on which states in paragraph "7.1 Task management function procedure calls"
that the "Additional Response Information" output argument for a Task
management function procedure call is 3 bytes.

Last but not least I've verified this by sending a logical unit reset task
management call with an invalid lun to an actual uasp device, and received
back a response-iu with byte 6 being 0, and byte 7 being 9, which is the
responce code for an invalid iu, which confirms that the response code is
being reported in byte 7 of the response iu rather then in byte 6.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
uas: s/ui/iu/

The various uas data structures are called IU-s, which is short for
Information Unit, rather then UI-s.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb: Add max_streams attribute to endpoint info

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
usb: Add usb_device_alloc/free_streams

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
xhci: Call usb_device_alloc/free_streams

Note this code is not as KISS as I would like, the reason for this is that
the Linux kernel interface wants streams on eps belonging to one interface
to be allocated in one call. Things will also work if we do this one ep at a
time (as long as all eps support the same amount of streams), but lets stick
to the kernel API.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
block: make BdrvRequestFlags public

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: add flags to bdrv_*_write_zeroes

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: introduce BDRV_REQ_MAY_UNMAP request flag

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: add logical block provisioning info to BlockDriverInfo

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: add wrappers for logical block provisioning information

This adds 2 wrappers to read the unallocated_blocks_are_zero and
can_write_zeroes_with_unmap info from the BDI. The wrappers are
required to check for the existence of a backing_hd and
if the devices are opened with the correct flags.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block/iscsi: add .bdrv_get_info

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>