linux/drivers/virtio/Kconfig
Jason Wang c346dae4f3 virtio: disable notification hardening by default
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>
2022-06-24 02:49:48 -04:00

170 lines
4.9 KiB
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# SPDX-License-Identifier: GPL-2.0-only
config VIRTIO
tristate
help
This option is selected by any driver which implements the virtio
bus, such as CONFIG_VIRTIO_PCI, CONFIG_VIRTIO_MMIO, CONFIG_RPMSG
or CONFIG_S390_GUEST.
config VIRTIO_PCI_LIB
tristate
help
Modern PCI device implementation. This module implements the
basic probe and control for devices which are based on modern
PCI device with possible vendor specific extensions. Any
module that selects this module must depend on PCI.
config VIRTIO_PCI_LIB_LEGACY
tristate
help
Legacy PCI device (Virtio PCI Card 0.9.x Draft and older device)
implementation.
This module implements the basic probe and control for devices
which are based on legacy PCI device. Any module that selects this
module must depend on PCI.
menuconfig VIRTIO_MENU
bool "Virtio drivers"
default y
if VIRTIO_MENU
config VIRTIO_HARDEN_NOTIFICATION
bool "Harden virtio notification"
help
Enable this to harden the device notifications and suppress
those that happen at a time where notifications are illegal.
Experimental: Note that several drivers still have bugs that
may cause crashes or hangs when correct handling of
notifications is enforced; depending on the subset of
drivers and devices you use, this may or may not work.
If unsure, say N.
config VIRTIO_PCI
tristate "PCI driver for virtio devices"
depends on PCI
select VIRTIO_PCI_LIB
select VIRTIO
help
This driver provides support for virtio based paravirtual device
drivers over PCI. This requires that your VMM has appropriate PCI
virtio backends. Most QEMU based VMMs should support these devices
(like KVM or Xen).
If unsure, say M.
config VIRTIO_PCI_LEGACY
bool "Support for legacy virtio draft 0.9.X and older devices"
default y
depends on VIRTIO_PCI
select VIRTIO_PCI_LIB_LEGACY
help
Virtio PCI Card 0.9.X Draft (circa 2014) and older device support.
This option enables building a transitional driver, supporting
both devices conforming to Virtio 1 specification, and legacy devices.
If disabled, you get a slightly smaller, non-transitional driver,
with no legacy compatibility.
So look out into your driveway. Do you have a flying car? If
so, you can happily disable this option and virtio will not
break. Otherwise, leave it set. Unless you're testing what
life will be like in The Future.
If unsure, say Y.
config VIRTIO_VDPA
tristate "vDPA driver for virtio devices"
depends on VDPA
select VIRTIO
help
This driver provides support for virtio based paravirtual
device driver over vDPA bus. For this to be useful, you need
an appropriate vDPA device implementation that operates on a
physical device to allow the datapath of virtio to be
offloaded to hardware.
If unsure, say M.
config VIRTIO_PMEM
tristate "Support for virtio pmem driver"
depends on VIRTIO
depends on LIBNVDIMM
help
This driver provides access to virtio-pmem devices, storage devices
that are mapped into the physical address space - similar to NVDIMMs
- with a virtio-based flushing interface.
If unsure, say Y.
config VIRTIO_BALLOON
tristate "Virtio balloon driver"
depends on VIRTIO
select MEMORY_BALLOON
select PAGE_REPORTING
help
This driver supports increasing and decreasing the amount
of memory within a KVM guest.
If unsure, say M.
config VIRTIO_MEM
tristate "Virtio mem driver"
depends on X86_64 || ARM64
depends on VIRTIO
depends on MEMORY_HOTPLUG
depends on MEMORY_HOTREMOVE
depends on CONTIG_ALLOC
depends on EXCLUSIVE_SYSTEM_RAM
help
This driver provides access to virtio-mem paravirtualized memory
devices, allowing to hotplug and hotunplug memory.
This driver was only tested under x86-64 and arm64, but should
theoretically work on all architectures that support memory hotplug
and hotremove.
If unsure, say M.
config VIRTIO_INPUT
tristate "Virtio input driver"
depends on VIRTIO
depends on INPUT
help
This driver supports virtio input devices such as
keyboards, mice and tablets.
If unsure, say M.
config VIRTIO_MMIO
tristate "Platform bus driver for memory mapped virtio devices"
depends on HAS_IOMEM && HAS_DMA
select VIRTIO
help
This drivers provides support for memory mapped virtio
platform device driver.
If unsure, say N.
config VIRTIO_MMIO_CMDLINE_DEVICES
bool "Memory mapped virtio devices parameter parsing"
depends on VIRTIO_MMIO
help
Allow virtio-mmio devices instantiation via the kernel command line
or module parameters. Be aware that using incorrect parameters (base
address in particular) can crash your system - you have been warned.
See Documentation/admin-guide/kernel-parameters.rst for details.
If unsure, say 'N'.
config VIRTIO_DMA_SHARED_BUFFER
tristate
depends on DMA_SHARED_BUFFER
help
This option adds a flavor of dma buffers that are backed by
virtio resources.
endif # VIRTIO_MENU