Instead of having a global flag to require restricted memory access
for all virtio devices, introduce a callback which can select that
requirement on a per-device basis.
For convenience add a common function returning always true, which can
be used for use cases like SEV.
Per default use a callback always returning false.
As the callback needs to be set in early init code already, add a
virtio anchor which is builtin in case virtio is enabled.
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 guest using Xen
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20220622063838.8854-2-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
We try to harden virtio device notifications in 8b4ec69d7e ("virtio:
harden vring IRQ"). It works with the assumption that the driver or
core can properly call virtio_device_ready() at the right
place. Unfortunately, this seems to be not true and uncover various
bugs of the existing drivers, mainly the issue of using
virtio_device_ready() incorrectly.
So let's add a Kconfig option and disable it by default. It gives
us time to fix the drivers and then we can consider re-enabling it.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220622012940.21441-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Instead of using arch_has_restricted_virtio_memory_access() together
with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those
with platform_has() and a new platform feature
PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Borislav Petkov <bp@suse.de>
This is a rework on the previous IRQ hardening that is done for
virtio-pci where several drawbacks were found and were reverted:
1) try to use IRQF_NO_AUTOEN which is not friendly to affinity managed IRQ
that is used by some device such as virtio-blk
2) done only for PCI transport
The vq->broken is re-used in this patch for implementing the IRQ
hardening. The vq->broken is set to true during both initialization
and reset. And the vq->broken is set to false in
virtio_device_ready(). Then vring_interrupt() can check and return
when vq->broken is true. And in this case, switch to return IRQ_NONE
to let the interrupt core aware of such invalid interrupt to prevent
IRQ storm.
The reason of using a per queue variable instead of a per device one
is that we may need it for per queue reset hardening in the future.
Note that the hardening is only done for vring interrupt since the
config interrupt hardening is already done in commit 22b7050a02
("virtio: defer config changed notifications"). But the method that is
used by config interrupt can't be reused by the vring interrupt
handler because it uses spinlock to do the synchronization which is
expensive.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Vineeth Vijayan <vneethv@linux.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220527060120.20964-9-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
This patch addresses the checkpatch.pl warning where unsigned int is
preferred over unsigned.
Signed-off-by: Solomon Tan <solomonbstoner@protonmail.ch>
Message-Id: <YlzS49Wo8JMDhKOt@ArchDesktop>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This reverts commit 8d65bc9a5b.
We reverted the problematic changes, no more need for work
arounds on restore.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
After waking up a suspended VM, the kernel prints the following trace
for virtio drivers which do not directly call virtio_device_ready() in
the .restore:
PM: suspend exit
irq 22: nobody cared (try booting with the "irqpoll" option)
Call Trace:
<IRQ>
dump_stack_lvl+0x38/0x49
dump_stack+0x10/0x12
__report_bad_irq+0x3a/0xaf
note_interrupt.cold+0xb/0x60
handle_irq_event+0x71/0x80
handle_fasteoi_irq+0x95/0x1e0
__common_interrupt+0x6b/0x110
common_interrupt+0x63/0xe0
asm_common_interrupt+0x1e/0x40
? __do_softirq+0x75/0x2f3
irq_exit_rcu+0x93/0xe0
sysvec_apic_timer_interrupt+0xac/0xd0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x12/0x20
arch_cpu_idle+0x12/0x20
default_idle_call+0x39/0xf0
do_idle+0x1b5/0x210
cpu_startup_entry+0x20/0x30
start_secondary+0xf3/0x100
secondary_startup_64_no_verify+0xc3/0xcb
</TASK>
handlers:
[<000000008f9bac49>] vp_interrupt
[<000000008f9bac49>] vp_interrupt
Disabling IRQ #22
This happens because we don't invoke .enable_cbs callback in
virtio_device_restore(). That callback is used by some transports
(e.g. virtio-pci) to enable interrupts.
Let's fix it, by calling virtio_device_ready() as we do in
virtio_dev_probe(). This function calls .enable_cts callback and sets
DRIVER_OK status bit.
This fix also avoids setting DRIVER_OK twice for those drivers that
call virtio_device_ready() in the .restore.
Fixes: d50497eb4e ("virtio_config: introduce a new .enable_cbs method")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20220322114313.116516-1-sgarzare@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The feature negotiation was designed in a way that
makes it possible for devices to know which config
fields will be accessed by drivers.
This is broken since commit 404123c2db ("virtio: allow drivers to
validate features") with fallout in at least block and net. We have a
partial work-around in commit 2f9a174f91 ("virtio: write back
F_VERSION_1 before validate") which at least lets devices find out which
format should config space have, but this is a partial fix: guests
should not access config space without acknowledging features since
otherwise we'll never be able to change the config space format.
To fix, split finalize_features from virtio_finalize_features and
call finalize_features with all feature bits before validation,
and then - if validation changed any bits - once again after.
Since virtio_finalize_features no longer writes out features
rename it to virtio_features_ok - since that is what it does:
checks that features are ok with the device.
As a side effect, this also reduces the amount of hypervisor accesses -
we now only acknowledge features once unless we are clearing any
features when validating (which is uncommon).
IRC I think that this was more or less always the intent in the spec but
unfortunately the way the spec is worded does not say this explicitly, I
plan to address this at the spec level, too.
Acked-by: Jason Wang <jasowang@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 404123c2db ("virtio: allow drivers to validate features")
Fixes: 2f9a174f91 ("virtio: write back F_VERSION_1 before validate")
Cc: "Halil Pasic" <pasic@linux.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio_finalize_features is only used internally within virtio.
No reason to export it.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The virtio specification virtio-v1.1-cs01 states: "Transitional devices
MUST detect Legacy drivers by detecting that VIRTIO_F_VERSION_1 has not
been acknowledged by the driver." This is exactly what QEMU as of 6.1
has done relying solely on VIRTIO_F_VERSION_1 for detecting that.
However, the specification also says: "... the driver MAY read (but MUST
NOT write) the device-specific configuration fields to check that it can
support the device ..." before setting FEATURES_OK.
In that case, any transitional device relying solely on
VIRTIO_F_VERSION_1 for detecting legacy drivers will return data in
legacy format. In particular, this implies that it is in big endian
format for big endian guests. This naturally confuses the driver which
expects little endian in the modern mode.
It is probably a good idea to amend the spec to clarify that
VIRTIO_F_VERSION_1 can only be relied on after the feature negotiation
is complete. Before validate callback existed, config space was only
read after FEATURES_OK. However, we already have two regressions, so
let's address this here as well.
The regressions affect the VIRTIO_NET_F_MTU feature of virtio-net and
the VIRTIO_BLK_F_BLK_SIZE feature of virtio-blk for BE guests when
virtio 1.0 is used on both sides. The latter renders virtio-blk unusable
with DASD backing, because things simply don't work with the default.
See Fixes tags for relevant commits.
For QEMU, we can work around the issue by writing out the feature bits
with VIRTIO_F_VERSION_1 bit set. We (ab)use the finalize_features
config op for this. This isn't enough to address all vhost devices since
these do not get the features until FEATURES_OK, however it looks like
the affected devices actually never handled the endianness for legacy
mode correctly, so at least that's not a regression.
No devices except virtio net and virtio blk seem to be affected.
Long term the right thing to do is to fix the hypervisors.
Cc: <stable@vger.kernel.org> #v4.11
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: 82e89ea077 ("virtio-blk: Add validation for block size in config space")
Fixes: fe36cbe067 ("virtio_net: clear MTU when out of range")
Reported-by: markver@us.ibm.com
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20211011053921.1198936-1-pasic@linux.ibm.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
A recent change checking of_device_is_compatible on probe broke some
powerpc/pseries setups. Apparently there virtio devices do not have a
"compatible" property - they are matched by PCI vendor/device ids.
Let's just skip of_node setup but proceed with initialization like we
did previously.
Fixes: 694a1116b4 ("virtio: Bind virtio device to device-tree node")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Pull virtio updates from Michael Tsirkin:
- vduse driver ("vDPA Device in Userspace") supporting emulated virtio
block devices
- virtio-vsock support for end of record with SEQPACKET
- vdpa: mac and mq support for ifcvf and mlx5
- vdpa: management netlink for ifcvf
- virtio-i2c, gpio dt bindings
- misc fixes and cleanups
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (39 commits)
Documentation: Add documentation for VDUSE
vduse: Introduce VDUSE - vDPA Device in Userspace
vduse: Implement an MMU-based software IOTLB
vdpa: Support transferring virtual addressing during DMA mapping
vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap()
vdpa: Add an opaque pointer for vdpa_config_ops.dma_map()
vhost-iotlb: Add an opaque pointer for vhost IOTLB
vhost-vdpa: Handle the failure of vdpa_reset()
vdpa: Add reset callback in vdpa_config_ops
vdpa: Fix some coding style issues
file: Export receive_fd() to modules
eventfd: Export eventfd_wake_count to modules
iova: Export alloc_iova_fast() and free_iova_fast()
virtio-blk: remove unneeded "likely" statements
virtio-balloon: Use virtio_find_vqs() helper
vdpa: Make use of PFN_PHYS/PFN_UP/PFN_DOWN helper macro
vsock_test: update message bounds test for MSG_EOR
af_vsock: rename variables in receive loop
virtio/vsock: support MSG_EOR bit processing
vhost/vsock: support MSG_EOR bit processing
...
Pull driver core updates from Greg KH:
"Here is the big set of driver core patches for 5.15-rc1.
These do change a number of different things across different
subsystems, and because of that, there were 2 stable tags created that
might have already come into your tree from different pulls that did
the following
- changed the bus remove callback to return void
- sysfs iomem_get_mapping rework
Other than those two things, there's only a few small things in here:
- kernfs performance improvements for huge numbers of sysfs users at
once
- tiny api cleanups
- other minor changes
All of these have been in linux-next for a while with no reported
problems, other than the before-mentioned merge issue"
* tag 'driver-core-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (33 commits)
MAINTAINERS: Add dri-devel for component.[hc]
driver core: platform: Remove platform_device_add_properties()
ARM: tegra: paz00: Handle device properties with software node API
bitmap: extend comment to bitmap_print_bitmask/list_to_buf
drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI
topology: use bin_attribute to break the size limitation of cpumap ABI
lib: test_bitmap: add bitmap_print_bitmask/list_to_buf test cases
cpumask: introduce cpumap_print_list/bitmask_to_buf to support large bitmask and list
sysfs: Rename struct bin_attribute member to f_mapping
sysfs: Invoke iomem_get_mapping() from the sysfs open callback
debugfs: Return error during {full/open}_proxy_open() on rmmod
zorro: Drop useless (and hardly used) .driver member in struct zorro_dev
zorro: Simplify remove callback
sh: superhyway: Simplify check in remove callback
nubus: Simplify check in remove callback
nubus: Make struct nubus_driver::remove return void
kernfs: dont call d_splice_alias() under kernfs node lock
kernfs: use i_lock to protect concurrent inode updates
kernfs: switch kernfs to use an rwsem
kernfs: use VFS negative dentry caching
...
Pull virtio updates from Michael Tsirkin:
"vhost, vdpa, and virtio cleanups and fixes
A very quiet cycle, no new features"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
MAINTAINERS: add URL for virtio-mem
vhost_vdpa: remove unnecessary spin_lock in vhost_vring_call
vringh: fix __vringh_iov() when riov and wiov are different
vdpa/mlx5: Setup driver only if VIRTIO_CONFIG_S_DRIVER_OK
s390: virtio: PV needs VIRTIO I/O device protection
virtio: let arch advertise guest's memory access restrictions
vhost_vdpa: Fix duplicate included kernel.h
vhost: reduce stack usage in log_used
virtio-mem: Constify mem_id_table
virtio_input: Constify id_table
virtio-balloon: Constify id_table
vdpa/mlx5: Fix failure to bring link up
vdpa/mlx5: Make use of a specific 16 bit endianness API
An architecture may restrict host access to guest memory,
e.g. IBM s390 Secure Execution or AMD SEV.
Provide a new Kconfig entry the architecture can select,
CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
the arch_has_restricted_virtio_memory_access callback to advertise
to VIRTIO common code when the architecture restricts memory access
from the host.
The common code can then fail the probe for any device where
VIRTIO_F_ACCESS_PLATFORM is required, but not set.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/1599728030-17085-2-git-send-email-pmorel@linux.ibm.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A virtio transport is free to implement some of the callbacks in
virtio_config_ops in a matter that they cannot be called from
atomic context (e.g. virtio-ccw, which maps a lot of the callbacks
to channel I/O, which is an inherently asynchronous mechanism).
This can be very surprising for developers using the much more
common virtio-pci transport, just to find out that things break
when used on s390.
The documentation for virtio_config_ops now contains a comment
explaining this, but it makes sense to add a might_sleep() annotation
to various wrapper functions in the virtio core to avoid surprises
later.
Note that annotations are NOT added to two classes of calls:
- direct calls from device drivers (all current callers should be
fine, however)
- calls which clearly won't be made from atomic context (such as
those ultimately coming in via the driver core)
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
In order to make caller do a simple cleanup, we split device_register
into device_initialize and device_add. device_initialize always succeeds,
so the caller can always use put_device when register_virtio_device faild.
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Some drivers can't support all features in all configurations. At the
moment we blindly set FEATURES_OK and later FAILED. Support this better
by adding a callback drivers can use to do some early checks.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
For XDP we will need to reset the queues to allow for buffer headroom
to be configured. In order to do this we need to essentially run the
freeze()/restore() code path. Unfortunately the locking requirements
between the freeze/restore and reset paths are different however so
we can not simply reuse the code.
This patch refactors the code path and adds a reset helper routine.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The virtio core uses a static ida named virtio_index_ida for
assigning index numbers to virtio devices during registration.
The ida core may allocate some internal idr cache layers and
an ida bitmap upon any ida allocation, and all these layers are
truely freed only upon the ida destruction. The virtio_index_ida
is not destroyed at present, leading to a memory leak when using
the virtio core as a module and atleast one virtio device is
registered and unregistered.
Fix this by invoking ida_destroy() in the virtio core module
exit.
Cc: stable@vger.kernel.org
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We added transitional device support to balloon driver,
so we don't need to black-list it in core anymore.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
virtio 1.0 devices require that drivers set VIRTIO_CONFIG_S_FEATURES_OK
after finalizing features.
virtio core missed doing this on restore, fix it up.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
legacy_only flag is now unused, drop it from core.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
transports need to be able to detect legacy-only
devices (ATM balloon only) to use legacy path
to drive them.
Add a core API to do just that.
The implementation just blacklists balloon:
not too pretty, but let's not over-engineer.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
virtio-blk has some legacy feature bits that modern drivers
must not negotiate, but are needed for old legacy hosts
(that e.g. don't support virtio-scsi).
Allow a separate legacy feature table for such cases.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Change u32 to u64, and use BIT_ULL and 1ULL everywhere.
Note: transports are unchanged, and only set low 32 bit.
This guarantees that no transport sets e.g. VERSION_1
by mistake without proper support.
Based on patch by Rusty.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
It seemed like a good idea to use bitmap for features
in struct virtio_device, but it's actually a pain,
and seems to become even more painful when we get more
than 32 feature bits. Just change it to a u32 for now.
Based on patch by Rusty.
Suggested-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Defer config changed notifications that arrive during
probe/scan/freeze/restore.
This will allow drivers to set DRIVER_OK earlier, without worrying about
racing with config change interrupts.
This change will also benefit old hypervisors (before 2009)
that send interrupts without checking DRIVER_OK: previously,
the callback could race with driver-specific initialization.
This will also help simplify drivers.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cosmetic changes)
This is in preparation to extending config changed event handling
in core.
Wrapping these in an API also seems to make for a cleaner code.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Replace duplicated code in all transports with a single wrapper in
virtio.c.
The only functional change is in virtio_mmio.c: if a buggy device sends
us an interrupt before driver is set, we previously returned IRQ_NONE,
now we return IRQ_HANDLED.
As this must not happen in practice, this does not look like a big deal.
See also commit 3fff0179e3
virtio-pci: do not oops on config change if driver not loaded.
for the original motivation behind the driver check.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pull virtio update from Rusty Russell:
"Some nice cleanups, and even a patch my wife did as a "live" demo for
Latinoware 2012.
There's a slightly non-trivial merge in virtio-net, as we cleaned up
the virtio add_buf interface while DaveM accepted the mq virtio-net
patches."
* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (27 commits)
virtio_console: Add support for remoteproc serial
virtio_console: Merge struct buffer_token into struct port_buffer
virtio: add drv_to_virtio to make code clearly
virtio: use dev_to_virtio wrapper in virtio
virtio-mmio: Fix irq parsing in command line parameter
virtio_console: Free buffers from out-queue upon close
virtio: Convert dev_printk(KERN_<LEVEL> to dev_<level>(
virtio_console: Use kmalloc instead of kzalloc
virtio_console: Free buffer if splice fails
virtio: tools: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: scsi: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: rpmsg: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: net: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: console: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: make virtqueue_add_buf() returning 0 on success, not capacity.
virtio: console: don't rely on virtqueue_add_buf() returning capacity.
virtio_net: don't rely on virtqueue_add_buf() returning capacity.
virtio-net: remove unused skb_vnet_hdr->num_sg field
virtio-net: correct capacity math on ring full
virtio: move queue_index and num_free fields into core struct virtqueue.
...
