virtio: support modern devices

fixes #17239 #17238

Change-Id: Ia5b6347110a60fab18852079b30dca6301010474
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6995
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

kernel: Drop non-standard GNU inline assignment syntax

* We needed this previously due to our gcc2 compiled kernel.
* Now that our kernel is always latest gcc, we can move to the
c++20 syntax for inline assignment.
* Improves compatibility with clang, less GNU-specific stuff

Change-Id: Ib7272a0a52554a31e9a0e788fd3f031db9049795
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5898
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

VirtioModule: Fix PVS773

The function was exited without releasing the 'device' pointer.

Change-Id: I19fcda340a6acf16c3fca243de6128d7218e379d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4282
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

virtio: add clear_feature hook.

Change-Id: I282ffc65a7bd692145626ab4272c5df4a792e9d4
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2383
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

virtio: Rework queue_dequeue to return a boolean.

It previously returned the cookie directly, which made it impossible
to distinguish between a NULL cookie and the function not having
anything to dequeue. This lead to some code setting a cookie that was
not actually used.

Return the dequeue status as a boolean and provide the cookie with an
optionally handed in pointer instead and adjust all users.

Change-Id: Iaac1726ac4bc7ae42bb96b8f0915852b6def5822
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1814
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

virtio: Replace size return with usedLength in queue_dequeue.

The size was in fact the count of physical entries that were used. That
number must necessarily be the same as the number given when adding to
the queue, so that number isn't really interesting. Consequently none
of the users of that API made use of it.

Return the used length instead, which is the way virtio signals how much
valid data resides in the dequeued buffer. This is for example important
to know the frame length of incoming packets in virtio_net.

virtio: add driver for the virtio balloon device

* how-to for qemu: command line option: -balloon virtio
* in the monitor view
- to switch the vm size to 500MB: balloon 500
- to display balloon info: info balloon

virtio: add API to uninit a device.

* free interrupts, free queues, return to init state.
* this will be used by virtio_net on interface uninit.

Change-Id: I7c1e6facc37cf6bfe19628576fdf2c0bac9e5c38

virtio: refactor to have a handler per queue.

* enable to iterate on available entries in one interrupt call.
* negociate -> negotiate, (void *) -> (void* ), thanks axel and philippe!

Change-Id: Ie2d290797abcbf4c0f3cb5bfff71d091bb800fa6

virtio: add queue_is_full(), queue_is_empty(), queue_size() hooks.

virtio*: remove trailing spaces

virtio: changed a bit the driver API by adding a driverCookie.

* the processing of requests in drivers is eased a bit with this change, but
this could be improved for instance by enabling a driver to dequeue items
in a service thread instead of the interrupt handler.
* made a few methods const.

Virtio: added drivers for PCI busses, bus manager and block device.

* the Virtio PCI bus driver exposes a Virtio controller to the Virtio bus manager,
which in turn exposes a Virtio device consumed by Virtio drivers. Drivers follow the
new driver model.
* virtio_block handles Virtio block devices under disk/virtual/virtio_block/x/raw.
* Here is the Qemu command line option for Virtio disk devices:
-drive file=haiku.image,if=virtio
* the PCI bus driver currently supports only legacy interrupts (no MSI(-X) yet).
* There is room for improvements in the bus manager:
- it notifies the host for each queued request, which isn't optimal.
- transfer descriptors should probably be simply preallocated (they are nicely
leaked at the moment).
- indirect descriptors are not supported yet.
and in the block driver:
- get the id of the disk.
- implements flushing the cache.
- improves dma restrictions.
- do_io() should use a page for header descriptors instead of malloc(), which
could cross boundaries.
* The device manager tries to guess the driver based on the PCI device type, this
implies having to declare the "busses/virtio" path for each possible type
provided by Virtio. Thus future driver additions might require patching the device
manager.
* virtio.h is still private, the API is subject to changes.
* virtio_pci.h, virtio_blk.h, virtio_ring.h are copied unchanged from FreeBSD.

virtio: add queue_is_full(), queue_is_empty(), queue_size() hooks.

virtio*: remove trailing spaces

virtio: changed a bit the driver API by adding a driverCookie.

* the processing of requests in drivers is eased a bit with this change, but
this could be improved for instance by enabling a driver to dequeue items
in a service thread instead of the interrupt handler.
* made a few methods const.

Virtio: added drivers for PCI busses, bus manager and block device.

* the Virtio PCI bus driver exposes a Virtio controller to the Virtio bus manager,
which in turn exposes a Virtio device consumed by Virtio drivers. Drivers follow the
new driver model.
* virtio_block handles Virtio block devices under disk/virtual/virtio_block/x/raw.
* Here is the Qemu command line option for Virtio disk devices:
-drive file=haiku.image,if=virtio
* the PCI bus driver currently supports only legacy interrupts (no MSI(-X) yet).
* There is room for improvements in the bus manager:
- it notifies the host for each queued request, which isn't optimal.
- transfer descriptors should probably be simply preallocated (they are nicely
leaked at the moment).
- indirect descriptors are not supported yet.
and in the block driver:
- get the id of the disk.
- implements flushing the cache.
- improves dma restrictions.
- do_io() should use a page for header descriptors instead of malloc(), which
could cross boundaries.
* The device manager tries to guess the driver based on the PCI device type, this
implies having to declare the "busses/virtio" path for each possible type
provided by Virtio. Thus future driver additions might require patching the device
manager.
* virtio.h is still private, the API is subject to changes.
* virtio_pci.h, virtio_blk.h, virtio_ring.h are copied unchanged from FreeBSD.