Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NPeter Lieven <pl@kamp.de>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This adds support for VHDX image creation, for images of type "Fixed"
and "Dynamic".  "Differencing" types (i.e., VHDX images with backing
files) are currently not supported.

Options for image creation include:
    * log size:
        The size of the journaling log for VHDX.  Minimum is 1MB,
        and it must be a multiple of 1MB. Invalid log sizes will be
        silently fixed by rounding up to the nearest MB.

        Default is 1MB.

    * block size:
        This is the size of a payload block.  The range is 1MB to 256MB,
        inclusive, and must be a multiple of 1MB as well.  Invalid sizes
        and multiples will be silently fixed.  If '0' is passed, then
        a sane size is chosen (depending on virtual image size).

        Default is 0 (Auto-select).

    * subformat:
        - "dynamic"
            An image without data pre-allocated.
        - "fixed"
            An image with data pre-allocated.

        Default is "dynamic"

When creating the image file, the lettered sections are created:

-----------------------------------------------------------------.
|   (A)    |   (B)    |    (C)    |     (D)       |     (E)
|  File ID |  Header1 |  Header 2 |  Region Tbl 1 |  Region Tbl 2
|          |          |           |               |
.-----------------------------------------------------------------.
0         64KB      128KB       192KB           256KB          320KB

.---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
|     (F)     |     (G)       |    (H)    |
| Journal Log |  BAT / Bitmap |  Metadata |  .... data ......
|             |               |           |
.---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
1MB         (var.)          (var.)      (var.)
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This is preperation for vhdx_create().  The ability to write headers,
and calculate the number of BAT entries will be needed within the
create() functions, so move this relevant code into helper functions.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

In preparation for vhdx_create(), move more endian translation
functions out to vhdx-endian.c.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Bit shifting can be fun, but in this case it was unnecessary.  The
upper 44 bits of the 64-bit BAT entry is specifies the File Offset,
so we shifted the bits to get access to the value.

However, per the spec the value is in MB.  So we dutifully shifted back
to the left by 20 bits, to convert to a true uint64_t file offset.

This replaces those steps with just a bit mask, to get rid of the lower
20 bits instead.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This adds support for writing to VHDX image files, using coroutines.
Writes into the BAT table goes through the VHDX log.  Currently, BAT
table writes occur when expanding a dynamic VHDX file, and allocating a
new BAT entry.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Regions in the image file cannot overlap - the log, region tables,
and metdata must all be unique and non-overlapping.

This adds region checking by means of a QLIST; there can be a variable
number of regions and metadata (there may be metadata or region tables
that we do not recognize / know about, but are not required).

This adds the capability to register a region for later checking, and
to check against registered regions for any overlap.

Also, if neither the BAT or Metadata region tables are found, return
error.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This adds support for VHDX v0 logs, as specified in Microsoft's
VHDX Specification Format v1.00:
https://www.microsoft.com/en-us/download/details.aspx?id=34750

The following support is added:

* Log parsing, and validation - validate that an existing log
  is correct.

* Log search - search through an existing log, to find any valid
  sequence of entries.

* Log replay and flush - replay an existing log, and flush/clear
  the log when complete.

The VHDX log is a circular buffer, with elements (sectors) of 4KB.

A log entry is a variably-length number of sectors, that is
comprised of a header and 'descriptors', that describe each sector.

A log may contain multiple entries, know as a log sequence.  In a log
sequence, each log entry immediately follows the previous entry, with an
incrementing sequence number.  There can only ever be one active and
valid sequence in the log.

Each log entry must match the file log GUID in order to be valid (along
with other criteria).  Once we have flushed all valid log entries, we
marked the file log GUID to be zero, which indicates a buffer with no
valid entries.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Allow tracking of first file write in the VHDX image, as well as
the ability to update the GUID in the header.  This is in preparation
for log support.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This moves the endian translation functions out from the vhdx.c source,
into a separate source file. In addition to the previously defined
endian functions, new endian translation functions for log support are
added as well.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

In preparation for VHDX log support, move these structures to the
header.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This adds the ability to update the headers in a VHDX image, including
generating a new MS-compatible GUID.

As VHDX depends on uuid.h, VHDX is now a configurable build option.  If
VHDX support is enabled, that will also enable uuid as well.  The
default is to have VHDX enabled.

To enable/disable VHDX:  --enable-vhdx, --disable-vhdx
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Just a couple of minor comments to help note where allocated
buffers are freed, and a typo fix.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This blocks migration for VHDX image files, until the
functionality can be supported.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Add an Error ** parameter to BlockDriver.bdrv_open and
BlockDriver.bdrv_file_open to allow more specific error messages.
Signed-off-by: NMax Reitz <mreitz@redhat.com>

This adds in read-only support to the VHDX image format.  This supports
reads for fixed-size, and dynamic sized VHDX images.

Differencing files are still unsupported.

The image must be opened without BDRV_O_RDWR set, because we do not
yet update the headers.  I.e., pass 'readonly=on' in the drive image
options from the QEMU commandline.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This is the initial block driver framework for VHDX image support
(i.e. Hyper-V image file formats), that supports opening VHDX files, and
parsing the headers.

This commit does not yet enable:
    - reading
    - writing
    - updating the header
    - differencing files (images with parents)
    - log replay / dirty logs (only clean images)

This is based on Microsoft's VHDX specification:
    "VHDX Format Specification v0.95", published 4/12/2012
    https://www.microsoft.com/en-us/download/details.aspx?id=29681Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>