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>