Move qapi-schema.json to qapi/, so it's next to its modules, and all
files get generated to qapi/, not just the ones generated for modules.
Consistently name the generated files qapi-MODULE.EXT:
qmp-commands.[ch] become qapi-commands.[ch], qapi-event.[ch] become
qapi-events.[ch], and qmp-introspect.[ch] become qapi-introspect.[ch].
This gets rid of the temporary hacks in scripts/qapi/commands.py,
scripts/qapi/events.py, and scripts/qapi/common.py.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180211093607.27351-28-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
[eblake: Fix trailing dot in tpm.c, undo temporary hack for OSX toolchain]
Signed-off-by: Eric Blake <eblake@redhat.com>
This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.
While there, separate #include from file comment with a blank line,
and drop a useless comment on why qemu/osdep.h is included first.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-5-armbru@redhat.com>
[Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
When using a mouse's scroll wheel in a guest with
the cocoa front-end, the mouse pointer moves up
and down instead of scrolling the window. This
patch fixes this problem.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 20180108180707.7976-1-programmingkidx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Send those ctrl-alt key combos that QEMU doesn't treat specially to
the guest rather than ignoring them.
All the case where we do special handling of ctrl-alt-X exit the
event handling using a "return" statement, so we can simply allow
the rest to fall through into the normal key handling by deleting
the now-spurious "else".
We take the opportunity to clean up some oddly-formatted and
now rather uninformative comments by removing them.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Currently the cocoa user interface relis on the user pushing
control-alt to ungrab the mouse. This is patch changes the key
combination to control-alt-g to be in line with the GTK user
interface.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 20171102213907.11443-1-programmingkidx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Make scrolling in the monitor work, by correctly passing through
control+key combinations.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 20171101154607.1582-1-programmingkidx@gmail.com
[PMM: fixed coding style nits; cleaned up commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Fix console selection keys so that the right console is selected.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 20171005190449.15591-1-programmingkidx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The [NSEvent modifierFlags] method returns an NSEventModifierFlags type value in Mac OS 10.10. It use to be of type NSUInteger. Replacing NSEventModifierFlags with NSUInteger allows for the cooca.m file to be compiled on older versions of Mac OS. This patch was been tested on Mac OS 10.6 and Mac OS 10.12 without problem.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: F6C36C1A-4661-48F4-BEA6-3994889927D0@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Programs running inside of QEMU can sometimes use more CPU time than is really
needed. To solve this problem, we just need to throttle the virtual CPU. This
feature will stop laptops from burning up.
This patch adds a menu called Speed that has menu items from 100% to 1% that
represent the speed options. 100% is full speed and 1% is slowest.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: D6FAAABF-064D-49C0-B572-C73679F34052@gmail.com
[PMM: Moved "mark 100% menu item as checked initially" code to
after menu item is allocated, not before it]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
I had two problems with QEMU on macOS:
1) Sometimes when alt-tabbing to QEMU it would act as if the 'a' key
was pressed so I'd get 'aaaaaaaaa....'.
2) Using Sikuli to programatically send keys to the QEMU window text
like "foo_bar" would come out as "fooa-bar".
They looked similar and after much digging the problem turned out to be
the same. When QEMU's ui/cocoa.m received an NSFlagsChanged NSEvent it
looked at the keyCode to determine what modifier key changed. This
usually works fine but sometimes the keyCode is 0 and the app should
instead be looking at the modifierFlags bitmask. Key code 0 is the 'a'
key.
I added code that handles keyCode == 0 differently. It checks the
modifierFlags and if they differ from QEMU's idea of which modifier
keys are currently pressed it toggles those changed keys.
This fixes my problems and seems work fine.
Signed-off-by: Ian McKellar <ianloic@google.com>
Message-id: 20170526233816.47627-1-ianloic@google.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Time to wire up all the call sites that request a shutdown or
reset to use the enum added in the previous patch.
It would have been less churn to keep the common case with no
arguments as meaning guest-triggered, and only modified the
host-triggered code paths, via a wrapper function, but then we'd
still have to audit that I didn't miss any host-triggered spots;
changing the signature forces us to double-check that I correctly
categorized all callers.
Since command line options can change whether a guest reset request
causes an actual reset vs. a shutdown, it's easy to also add the
information to reset requests.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au> [ppc parts]
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> [SPARC part]
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x parts]
Message-Id: <20170515214114.15442-5-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This patch refactors ui/input.c to support absolute axis
minimum values other than 0. All dependent calls to qemu_input_queue_abs
have been updated to explicitly supply 0 as the axis minimum value.
Signed-off-by: Philippe Voinov <philippevoinov@gmail.com>
Message-id: 20170505133952.29885-1-philippevoinov@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
macOS 10.12 deprecated/replaced many AppKit constants to make naming
more consistent. Use the new constants, and #define them to the
old constants when compiling against a pre-10.12 SDK.
Signed-off-by: Brendan Shanks <brendan@bslabs.net>
Message-id: 20170425062952.99149-1-brendan@bslabs.net
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add the ability for the user to use .toast files with QEMU. This format works
just like ISO files.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 0C9DA454-E3DC-4291-806E-9A96557DE833@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Merge what is left of qemu-tech into the main manual as an appendix.
Ultimately we should have a new internals manual built from docs/, and
then the "Translator Internals" parts of qemu-tech could move to docs/
as well. The bits on limitation and features of CPU emulation should
remain in qemu-doc.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to remove the need for BlockBackend names in the external API,
we want to allow qdev device names in all device related commands.
This converts blockdev-change-medium to accept a qdev device name.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In order to remove the need for BlockBackend names in the external API,
we want to allow qdev device names in all device related commands.
This converts eject to accept a qdev device name.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The about dialog in QEMU on Mac OS X is very plain and unhelpful. This patch
makes the about dialog look a lot better and have some descriptive information
on what version of QEMU the user is running.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: ED59936E-3EB2-46AB-9E33-AB26E382B884@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Allow the user to select .cdr files in the file open dialog.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 32C964D4-3F17-47B7-AE7E-593E6BFD8855@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch removes the pc/xt keycode map and replaces it with the QKeyCode
keymap.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Make the help menus actually work. The code will search thru three different
locations for the help file. If it can't be found a dialog will tell the user
the file can't be found.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: F6B689F9-4DBD-4C50-BC38-35E5DD03D396@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
All lowercase, use-dash instead of CamelCase.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Include "qemu/osdep.h". (This is a manual commit equivalent
to what the clean-includes script would do, because that
script can't handle ObjectiveC source files.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454084614-5365-1-git-send-email-peter.maydell@linaro.org
When munging enum values, the fact that we were passing the entire
prefix + value through camel_to_upper() meant that enum values
spelled with CamelCase could be turned into CAMEL_CASE. However,
this provides a potential collision (both OneTwo and One-Two would
munge into ONE_TWO) for enum types, when the same two names are
valid side-by-side as QAPI member names. By changing the generation
of enum constants to always be prefix + '_' + c_name(value,
False).upper(), and ensuring that there are no case collisions (in
the next patches), we no longer have to worry about names that
would be distinct as QAPI members but collide as variant tag names,
without having to think about what munging the heuristics in
camel_to_upper() will actually perform on an enum value.
Making the change will affect enums that did not follow coding
conventions, using 'CamelCase' rather than desired 'lower-case'.
Thankfully, there are only two culprits: InputButton and ErrorClass.
We already tweaked ErrorClass to make it an alias of QapiErrorClass,
where only the alias needs changing rather than the whole tree. So
the bulk of this change is modifying INPUT_BUTTON_WHEEL_UP to the
new INPUT_BUTTON_WHEELUP (and likewise for WHEELDOWN). That part
of this commit may later need reverting if we rename the enum
constants from 'WheelUp' to 'wheel-up' as part of moving
x-input-send-event to a stable interface; but at least we have
documentation bread crumbs in place to remind us (commit 513e7cd),
and it matches the fact that SDL constants are also spelled
SDL_BUTTON_WHEELUP.
Suggested by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-27-git-send-email-eblake@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Now that we guarantee the user doesn't have any enum values
beginning with a single underscore, we can use that for our
own purposes. Renaming ENUM_MAX to ENUM__MAX makes it obvious
that the sentinel is generated.
This patch was mostly generated by applying a temporary patch:
|diff --git a/scripts/qapi.py b/scripts/qapi.py
|index e6d014b..b862ec9 100644
|--- a/scripts/qapi.py
|+++ b/scripts/qapi.py
|@@ -1570,6 +1570,7 @@ const char *const %(c_name)s_lookup[] = {
| max_index = c_enum_const(name, 'MAX', prefix)
| ret += mcgen('''
| [%(max_index)s] = NULL,
|+// %(max_index)s
| };
| ''',
| max_index=max_index)
then running:
$ cat qapi-{types,event}.c tests/test-qapi-types.c |
sed -n 's,^// \(.*\)MAX,s|\1MAX|\1_MAX|g,p' > list
$ git grep -l _MAX | xargs sed -i -f list
The only things not generated are the changes in scripts/qapi.py.
Rejecting enum members named 'MAX' is now useless, and will be dropped
in the next patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-23-git-send-email-eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
[Rebased to current master, commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
When QEMU is brought to the foreground, the click event that activates QEMU
should not go to the guest. Accidents happen when they do go to the guest
without giving the user a chance to handle them. In particular, if the
guest input device is not an absolute-position one then the location of
the guest cursor (and thus the click) will likely not be the location of
the host cursor when it is clicked, and could be completely obscured
below another window. Don't send mouse clicks to QEMU unless the
window either has focus or has grabbed mouse events.
Reported-by: John Arbuckle <programmingkidx@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 1448551168-13196-1-git-send-email-peter.maydell@linaro.org
Add an option to qmp_blockdev_change_medium() which allows changing the
read-only status of the block device whose medium is changed.
Some drives do not have a inherently fixed read-only status; for
instance, floppy disks can be set read-only or writable independently of
the drive. Some users may find it useful to be able to therefore change
the read-only status of a block device when changing the medium.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Introduce a new QMP command 'blockdev-change-medium' which is intended
to replace the 'change' command for block devices. The existing function
qmp_change_blockdev() is accordingly renamed to
qmp_blockdev_change_medium().
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The mouse cursor can become blinky when being moved a lot. This patch fixes that
problem by issuing the redraw sooner.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: AAA87DD7-EC20-4F4B-B71E-C38461D9FCBA@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Eliminate this warning associated with the addRemovableDevicesMenuItems()
function:
ui/cocoa.m:1344:13: warning: function declaration isn't a prototype
[-Wstrict-prototypes]
static void addRemovableDevicesMenuItems()
^
ui/cocoa.m: In function 'addRemovableDevicesMenuItems':
ui/cocoa.m:1344:13: warning: old-style function definition [-Wold-style-definition]
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 7B365FC2-072B-4E8D-A1D9-922C2D691A83@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Eliminate this warning associated with the setting of the normalWindow's title:
ui/cocoa.m: In function '-[QemuCocoaAppController init]':
ui/cocoa.m:888:9: warning: format not a string literal and no format arguments
[-Wformat-security]
[normalWindow setTitle:[NSString stringWithFormat:@"QEMU"]];
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 57057D6E-C108-4AE1-8370-E7E6855B2F2C@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Removes the open dialog code that runs when no arguments are supplied with QEMU.
Not everyone needs a hard drive or cdrom to boot their target. A user might only
need to use their target's bios to do work. With that said, this patch removes
the unneeded open dialog code.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 33856864-321C-4367-9170-FB0BF81E789B@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When the user puts QEMU in the background while holding
down a key, QEMU will not receive the keyup event when
the user lets go of the key. When the user goes back to
QEMU, QEMU will think the key is still down causing
stuck key symptoms. This patch fixes this problem by
releasing all down keys when QEMU goes into the
background.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 7A3FA6EE-84C8-4422-A786-C899B7229D32@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch prevents the user from accidentally quitting QEMU by pushing
Command-Q or by pushing the close button on the main window. When
the user does one of these two things, a dialog box appears verifying
with the user if he or she wants to quit QEMU.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 29169A74-0347-47F5-934F-A5AD24C225CA@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Do not open a Cocoa window when another display is selected that will be
initialized later. The Cocoa display cannot be selected with -display,
so there is no need to check its argument.
Signed-off-by: Rainer Müller <raimue@codingfarm.de>
Reviewed-by: Andreas Färber <andreas.faerber@web.de>
Message-id: 1441807710-25431-1-git-send-email-raimue@codingfarm.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Adds all removable devices to the Machine menu as a Change and Eject menu
item pair. ide-cd0 would have a "Change ide-cd0..." and "Eject ide-cd0"
menu items.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add "Reset" and "Power Down" menu items to Machine menu.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add Machine menu to the Macintosh interface with pause
and resume menu items. These items can either pause or
resume execution of the guest operating system.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Message-id: 6D7AE6AA-0595-4FAD-AACF-9DFAB87248F0@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add any console that is available to the current emulator as a
menu item under the View menu.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
[PMM: Adjusted to apply after zoom-to-fit menu item was added;
create the View menu at the same time as all the others, and only
add the dynamically-determined items to it later]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In OSX 10.10, the NSOKButton and NSCancelButton constants are deprecated
and provoke compiler warnings. Avoid them by using the
NSFileHandlingPanelCancelButton and NSFileHandlingPanelOKButton constants
instead. These are the documented correct constants for the 10.6-and-up
beginSheetModalForWindow API we use. We also use the same method for
the pre-10.6 compatibility code path, but conveniently the constant
values are the same and the constant names have been present since 10.0.
Preferring the constant names that match the non-legacy API makes more
sense anyway.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1431296361-16981-7-git-send-email-peter.maydell@linaro.org
Our class QemuCocoaAppController implements the NSApplicationDelegate
interface, and we pass an object of this class to [NSApp setDelegate].
However, we weren't declaring in the class definition that we implemented
this interface; in OSX 10.10 this provokes the following (slighly
misleading) warning:
ui/cocoa.m:1031:24: warning: sending 'QemuCocoaAppController *' to parameter of
incompatible type 'id<NSFileManagerDelegate>'
[NSApp setDelegate:appController];
^~~~~~~~~~~~~
/System/Library/Frameworks/Foundation.framework/Headers/NSFileManager.h:109:47:
note: passing argument to parameter 'delegate' here
@property (assign) id <NSFileManagerDelegate> delegate NS_AVAILABLE(10_5,
2_0);
^
Annoyingly, this interface wasn't formally defined until OSX 10.6, so we
have to surround the relevant part of the @interface line with an ifdef.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1431296361-16981-5-git-send-email-peter.maydell@linaro.org
The type for openPanelDidEnd's returnCode argument should be NSInteger,
not int. This only matters for the OSX 10.5 code path where we pass
the method directly to an OSX function to call.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1431296361-16981-4-git-send-email-peter.maydell@linaro.org
The code that tries to test at both compiletime and runtime
for whether CGImageCreateWithImageInRect is supported provokes
a compile warning on OSX 10.3:
ui/cocoa.m:378:13: warning: comparison of function 'CGImageCreateWithImageInRect'
equal to a null pointer is always false[-Wtautological-pointer-compare]
if (CGImageCreateWithImageInRect == NULL) { // test if "CGImageCreateWithImageInRect" is
supported on host at runtime
^~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~
The simplest way to deal with this is just to drop this code,
since we don't in practice support OSX 10.4 anyway. (10.5 was
released in 2007 and is the last PPC version, so is the earliest
we really need to continue to support at all.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1431296361-16981-2-git-send-email-peter.maydell@linaro.org
This patch makes the -full-screen option actually instruct QEMU to
enter fullscreen at startup, on Mac OS X.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch makes several changes:
- Minimizes distorted full screen display by respecting aspect
ratios.
- Makes full screen mode available on Mac OS 10.7 and higher.
- Allows user to decide if video should be stretched to fill the
screen, using a menu item called "Zoom To Fit".
- Hides the normalWindow so it won't show up in full screen mode.
- Allows user to exit full screen mode.
Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
[PMM: minor whitespace tweaks, remove incorrectly duplicated
use of 'f' menu accelerator key]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch removes support for the cow file format.
Normally we do not break backwards compatibility but in this case there
is no impact and it is the most logical option. Extraordinary claims
require extraordinary evidence so I will show why removing the cow block
driver is the right thing to do.
The cow file format is the disk image format for Usermode Linux, a way
of running a Linux system in userspace. The performance of UML was
never great and it was hacky, but it enjoyed some popularity before
hardware virtualization support became mainstream.
QEMU's block/cow.c is supposed to read this image file format.
Unfortunately the file format was underspecified:
1. Earlier Linux versions used the MAXPATHLEN constant for the backing
filename field. The value of MAXPATHLEN can change, so Linux
switched to a 4096 literal but QEMU has a 1024 literal.
2. Padding was not used on the header struct (both in the Linux kernel
and in QEMU) so the struct layout varied across architectures. In
particular, i386 and x86_64 were different due to int64_t alignment
differences. Linux now uses __attribute__((packed)), QEMU does not.
Therefore:
1. QEMU cow images do not conform to the Linux cow image file format.
2. cow images cannot be shared between different host architectures.
This means QEMU cow images are useless and QEMU has not had bug reports
from users actually hitting these issues.
Let's get rid of this thing, it serves no purpose and no one will be
affected.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1410877464-20481-1-git-send-email-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Markus Armbruster
Gerd Hoffmann
John Arbuckle
Peter Maydell
Ian McKellar via Qemu-devel
Eric Blake
Philippe Voinov
Brendan Shanks
Paolo Bonzini
Kevin Wolf
Stefan Weil
Max Reitz
Rainer Müller
Stefan Hajnoczi