linux-stable/drivers/virtio/Kconfig

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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 ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
bool
help
This option is selected if the architecture may need to enforce
VIRTIO_F_ACCESS_PLATFORM
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_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
virtio-balloon: add support for providing free page reports to host Add support for the page reporting feature provided by virtio-balloon. Reporting differs from the regular balloon functionality in that is is much less durable than a standard memory balloon. Instead of creating a list of pages that cannot be accessed the pages are only inaccessible while they are being indicated to the virtio interface. Once the interface has acknowledged them they are placed back into their respective free lists and are once again accessible by the guest system. Unlike a standard balloon we don't inflate and deflate the pages. Instead we perform the reporting, and once the reporting is completed it is assumed that the page has been dropped from the guest and will be faulted back in the next time the page is accessed. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Cc: wei qi <weiqi4@huawei.com> Link: http://lkml.kernel.org/r/20200211224657.29318.68624.stgit@localhost.localdomain Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 03:05:05 +00:00
select PAGE_REPORTING
help
This driver supports increasing and decreasing the amount
of memory within a KVM guest.
If unsure, say M.
virtio-mem: Paravirtualized memory hotplug Each virtio-mem device owns exactly one memory region. It is responsible for adding/removing memory from that memory region on request. When the device driver starts up, the requested amount of memory is queried and then plugged to Linux. On request, further memory can be plugged or unplugged. This patch only implements the plugging part. On x86-64, memory can currently be plugged in 4MB ("subblock") granularity. When required, a new memory block will be added (e.g., usually 128MB on x86-64) in order to plug more subblocks. Only x86-64 was tested for now. The online_page callback is used to keep unplugged subblocks offline when onlining memory - similar to the Hyper-V balloon driver. Unplugged pages are marked PG_offline, to tell dump tools (e.g., makedumpfile) to skip them. User space is usually responsible for onlining the added memory. The memory hotplug notifier is used to synchronize virtio-mem activity against memory onlining/offlining. Each virtio-mem device can belong to a NUMA node, which allows us to easily add/remove small chunks of memory to/from a specific NUMA node by using multiple virtio-mem devices. Something that works even when the guest has no idea about the NUMA topology. One way to view virtio-mem is as a "resizable DIMM" or a DIMM with many "sub-DIMMS". This patch directly introduces the basic infrastructure to implement memory unplug. Especially the memory block states and subblock bitmaps will be heavily used there. Notes: - In case memory is to be onlined by user space, we limit the amount of offline memory blocks, to not run out of memory. This is esp. an issue if memory is added faster than it is getting onlined. - Suspend/Hibernate is not supported due to the way virtio-mem devices behave. Limited support might be possible in the future. - Reloading the device driver is not supported. Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: linux-acpi@vger.kernel.org Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-2-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-05-07 14:01:25 +00:00
config VIRTIO_MEM
tristate "Virtio mem driver"
default m
depends on X86_64
depends on VIRTIO
depends on MEMORY_HOTPLUG
virtio-mem: Paravirtualized memory hotplug Each virtio-mem device owns exactly one memory region. It is responsible for adding/removing memory from that memory region on request. When the device driver starts up, the requested amount of memory is queried and then plugged to Linux. On request, further memory can be plugged or unplugged. This patch only implements the plugging part. On x86-64, memory can currently be plugged in 4MB ("subblock") granularity. When required, a new memory block will be added (e.g., usually 128MB on x86-64) in order to plug more subblocks. Only x86-64 was tested for now. The online_page callback is used to keep unplugged subblocks offline when onlining memory - similar to the Hyper-V balloon driver. Unplugged pages are marked PG_offline, to tell dump tools (e.g., makedumpfile) to skip them. User space is usually responsible for onlining the added memory. The memory hotplug notifier is used to synchronize virtio-mem activity against memory onlining/offlining. Each virtio-mem device can belong to a NUMA node, which allows us to easily add/remove small chunks of memory to/from a specific NUMA node by using multiple virtio-mem devices. Something that works even when the guest has no idea about the NUMA topology. One way to view virtio-mem is as a "resizable DIMM" or a DIMM with many "sub-DIMMS". This patch directly introduces the basic infrastructure to implement memory unplug. Especially the memory block states and subblock bitmaps will be heavily used there. Notes: - In case memory is to be onlined by user space, we limit the amount of offline memory blocks, to not run out of memory. This is esp. an issue if memory is added faster than it is getting onlined. - Suspend/Hibernate is not supported due to the way virtio-mem devices behave. Limited support might be possible in the future. - Reloading the device driver is not supported. Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: linux-acpi@vger.kernel.org Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-2-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-05-07 14:01:25 +00:00
depends on MEMORY_HOTREMOVE
depends on CONTIG_ALLOC
virtio-mem: disallow mapping virtio-mem memory via /dev/mem We don't want user space to be able to map virtio-mem device memory directly (e.g., via /dev/mem) in order to have guarantees that in a sane setup we'll never accidentially access unplugged memory within the device-managed region of a virtio-mem device, just as required by the virtio-spec. As soon as the virtio-mem driver is loaded, the device region is visible in /proc/iomem via the parent device region. From that point on user space is aware of the device region and we want to disallow mapping anything inside that region (where we will dynamically (un)plug memory) until the driver has been unloaded cleanly and e.g., another driver might take over. By creating our parent IORESOURCE_SYSTEM_RAM resource with IORESOURCE_EXCLUSIVE, we will disallow any /dev/mem access to our device region until the driver was unloaded cleanly and removed the parent region. This will work even though only some memory blocks are actually currently added to Linux and appear as busy in the resource tree. So access to the region from user space is only possible a) if we don't load the virtio-mem driver. b) after unloading the virtio-mem driver cleanly. Don't build virtio-mem if access to /dev/mem cannot be restricticted -- if we have CONFIG_DEVMEM=y but CONFIG_STRICT_DEVMEM is not set. Link: https://lkml.kernel.org/r/20210920142856.17758-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Jason Wang <jasowang@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 02:35:53 +00:00
depends on EXCLUSIVE_SYSTEM_RAM
virtio-mem: Paravirtualized memory hotplug Each virtio-mem device owns exactly one memory region. It is responsible for adding/removing memory from that memory region on request. When the device driver starts up, the requested amount of memory is queried and then plugged to Linux. On request, further memory can be plugged or unplugged. This patch only implements the plugging part. On x86-64, memory can currently be plugged in 4MB ("subblock") granularity. When required, a new memory block will be added (e.g., usually 128MB on x86-64) in order to plug more subblocks. Only x86-64 was tested for now. The online_page callback is used to keep unplugged subblocks offline when onlining memory - similar to the Hyper-V balloon driver. Unplugged pages are marked PG_offline, to tell dump tools (e.g., makedumpfile) to skip them. User space is usually responsible for onlining the added memory. The memory hotplug notifier is used to synchronize virtio-mem activity against memory onlining/offlining. Each virtio-mem device can belong to a NUMA node, which allows us to easily add/remove small chunks of memory to/from a specific NUMA node by using multiple virtio-mem devices. Something that works even when the guest has no idea about the NUMA topology. One way to view virtio-mem is as a "resizable DIMM" or a DIMM with many "sub-DIMMS". This patch directly introduces the basic infrastructure to implement memory unplug. Especially the memory block states and subblock bitmaps will be heavily used there. Notes: - In case memory is to be onlined by user space, we limit the amount of offline memory blocks, to not run out of memory. This is esp. an issue if memory is added faster than it is getting onlined. - Suspend/Hibernate is not supported due to the way virtio-mem devices behave. Limited support might be possible in the future. - Reloading the device driver is not supported. Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: linux-acpi@vger.kernel.org Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-2-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-05-07 14:01:25 +00:00
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, 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