aboutsummaryrefslogtreecommitdiff
path: root/docs/system
diff options
context:
space:
mode:
Diffstat (limited to 'docs/system')
-rw-r--r--docs/system/arm/max78000.rst37
-rw-r--r--docs/system/arm/virt.rst9
-rw-r--r--docs/system/devices/cxl.rst11
-rw-r--r--docs/system/devices/net.rst50
-rw-r--r--docs/system/i386/amd-memory-encryption.rst2
-rw-r--r--docs/system/igvm.rst173
-rw-r--r--docs/system/images.rst2
-rw-r--r--docs/system/index.rst1
-rw-r--r--docs/system/introduction.rst2
-rw-r--r--docs/system/keys.rst.inc49
-rw-r--r--docs/system/linuxboot.rst2
-rw-r--r--docs/system/mux-chardev.rst.inc38
-rw-r--r--docs/system/target-arm.rst1
-rw-r--r--docs/system/target-i386.rst4
-rw-r--r--docs/system/virtio-net-failover.rst51
15 files changed, 361 insertions, 71 deletions
diff --git a/docs/system/arm/max78000.rst b/docs/system/arm/max78000.rst
new file mode 100644
index 0000000..3d95011
--- /dev/null
+++ b/docs/system/arm/max78000.rst
@@ -0,0 +1,37 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Analog Devices max78000 board (``max78000fthr``)
+================================================
+
+The max78000 is a Cortex-M4 based SOC with a RISC-V coprocessor. The RISC-V coprocessor is not supported.
+
+Supported devices
+-----------------
+
+ * Instruction Cache Controller
+ * UART
+ * Global Control Register
+ * True Random Number Generator
+ * AES
+
+Notable unsupported devices
+---------------------------
+
+ * I2C
+ * CNN
+ * CRC
+ * SPI
+
+Boot options
+------------
+
+The max78000 can be started using the ``-kernel`` option to load a
+firmware at address 0 as the ROM. As the ROM normally jumps to software loaded
+from the internal flash at address 0x10000000, loading your program there is
+generally advisable. If you don't have a copy of the ROM, the interrupt
+vector table from user firmware will do.
+Example:
+
+.. code-block:: bash
+
+ $ qemu-system-arm -machine max78000fthr -kernel max78000.bin -device loader,file=max78000.bin,addr=0x10000000
diff --git a/docs/system/arm/virt.rst b/docs/system/arm/virt.rst
index 6a719b9..10cbffc 100644
--- a/docs/system/arm/virt.rst
+++ b/docs/system/arm/virt.rst
@@ -31,6 +31,7 @@ Supported devices
The virt board supports:
- PCI/PCIe devices
+- CXL Fixed memory windows, root bridges and devices.
- Flash memory
- Either one or two PL011 UARTs for the NonSecure World
- An RTC
@@ -189,6 +190,14 @@ ras
acpi
Set ``on``/``off``/``auto`` to enable/disable ACPI.
+cxl
+ Set ``on``/``off`` to enable/disable CXL. More details in
+ :doc:`../devices/cxl`. The default is off.
+
+cxl-fmw
+ Array of CXL fixed memory windows describing fixed address routing to
+ target CXL host bridges. See :doc:`../devices/cxl`.
+
dtb-randomness
Set ``on``/``off`` to pass random seeds via the guest DTB
rng-seed and kaslr-seed nodes (in both "/chosen" and
diff --git a/docs/system/devices/cxl.rst b/docs/system/devices/cxl.rst
index e307caf..ca15a0d 100644
--- a/docs/system/devices/cxl.rst
+++ b/docs/system/devices/cxl.rst
@@ -384,6 +384,17 @@ An example of 4 devices below a switch suitable for 1, 2 or 4 way interleave::
-device cxl-type3,bus=swport3,persistent-memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem3,sn=0x4 \
-M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G,cxl-fmw.0.interleave-granularity=4k
+A simple arm/virt example featuring a single direct connected CXL Type 3
+Volatile Memory device::
+
+ qemu-system-aarch64 -M virt,gic-version=3,cxl=on -m 4g,maxmem=8g,slots=4 -cpu max -smp 4 \
+ ...
+ -object memory-backend-ram,id=vmem0,share=on,size=256M \
+ -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \
+ -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \
+ -device cxl-type3,bus=root_port13,volatile-memdev=vmem0,id=cxl-vmem0 \
+ -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G
+
Deprecations
------------
diff --git a/docs/system/devices/net.rst b/docs/system/devices/net.rst
index a3efbdc..4d787c3 100644
--- a/docs/system/devices/net.rst
+++ b/docs/system/devices/net.rst
@@ -85,13 +85,59 @@ passt doesn't require any capability or privilege. passt has
better performance than ``-net user``, full IPv6 support and better security
as it's a daemon that is not executed in QEMU context.
-passt can be connected to QEMU either by using a socket
-(``-netdev stream``) or using the vhost-user interface (``-netdev vhost-user``).
+passt_ can be used in the same way as the user backend (using ``-net passt``,
+``-netdev passt`` or ``-nic passt``) or it can be launched manually and
+connected to QEMU either by using a socket (``-netdev stream``) or by using
+the vhost-user interface (``-netdev vhost-user``).
+
+Using ``-netdev stream`` or ``-netdev vhost-user`` will allow the user to
+enable functionalities not available through the passt backend interface
+(like migration).
+
See `passt(1)`_ for more details on passt.
.. _passt: https://passt.top/
.. _passt(1): https://passt.top/builds/latest/web/passt.1.html
+To use the passt backend interface
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+There is no need to start the daemon as QEMU will do it for you.
+
+By default, passt will be started in the socket-based mode.
+
+.. parsed-literal::
+ |qemu_system| [...OPTIONS...] -nic passt
+
+ (qemu) info network
+ e1000e.0: index=0,type=nic,model=e1000e,macaddr=52:54:00:12:34:56
+ \ #net071: index=0,type=passt,stream,connected to pid 24846
+
+.. parsed-literal::
+ |qemu_system| [...OPTIONS...] -net nic -net passt,tcp-ports=10001,udp-ports=10001
+
+ (qemu) info network
+ hub 0
+ \ hub0port1: #net136: index=0,type=passt,stream,connected to pid 25204
+ \ hub0port0: e1000e.0: index=0,type=nic,model=e1000e,macaddr=52:54:00:12:34:56
+
+.. parsed-literal::
+ |qemu_system| [...OPTIONS...] -netdev passt,id=netdev0 -device virtio-net,mac=9a:2b:2c:2d:2e:2f,id=virtio0,netdev=netdev0
+
+ (qemu) info network
+ virtio0: index=0,type=nic,model=virtio-net-pci,macaddr=9a:2b:2c:2d:2e:2f
+ \ netdev0: index=0,type=passt,stream,connected to pid 25428
+
+To use the vhost-based interface, add the ``vhost-user=on`` parameter and
+select the virtio-net device:
+
+.. parsed-literal::
+ |qemu_system| [...OPTIONS...] -nic passt,model=virtio,vhost-user=on
+
+ (qemu) info network
+ virtio-net-pci.0: index=0,type=nic,model=virtio-net-pci,macaddr=52:54:00:12:34:56
+ \ #net006: index=0,type=passt,vhost-user,connected to pid 25731
+
To use socket based passt interface:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/docs/system/i386/amd-memory-encryption.rst b/docs/system/i386/amd-memory-encryption.rst
index 748f509..6c23f35 100644
--- a/docs/system/i386/amd-memory-encryption.rst
+++ b/docs/system/i386/amd-memory-encryption.rst
@@ -1,3 +1,5 @@
+.. _amd-sev:
+
AMD Secure Encrypted Virtualization (SEV)
=========================================
diff --git a/docs/system/igvm.rst b/docs/system/igvm.rst
new file mode 100644
index 0000000..79508d9
--- /dev/null
+++ b/docs/system/igvm.rst
@@ -0,0 +1,173 @@
+Independent Guest Virtual Machine (IGVM) support
+================================================
+
+IGVM files are designed to encapsulate all the information required to launch a
+virtual machine on any given virtualization stack in a deterministic way. This
+allows the cryptographic measurement of initial guest state for Confidential
+Guests to be calculated when the IGVM file is built, allowing a relying party to
+verify the initial state of a guest via a remote attestation.
+
+Although IGVM files are designed with Confidential Computing in mind, they can
+also be used to configure non-confidential guests. Multiple platforms can be
+defined by a single IGVM file, allowing a single IGVM file to configure a
+virtual machine that can run on, for example, TDX, SEV and non-confidential
+hosts.
+
+QEMU supports IGVM files through the user-creatable ``igvm-cfg`` object. This
+object is used to define the filename of the IGVM file to process. A reference
+to the object is added to the ``-machine`` to configure the virtual machine
+to use the IGVM file for configuration.
+
+Confidential platform support is provided through the use of
+the ``ConfidentialGuestSupport`` object. If the virtual machine provides an
+instance of this object then this is used by the IGVM loader to configure the
+isolation properties of the directives within the file.
+
+Further Information on IGVM
+---------------------------
+
+Information about the IGVM format, including links to the format specification
+and documentation for the Rust and C libraries can be found at the project
+repository:
+
+https://github.com/microsoft/igvm
+
+
+Supported Platforms
+-------------------
+
+Currently, IGVM files can be provided for Confidential Guests on host systems
+that support AMD SEV, SEV-ES and SEV-SNP with KVM. IGVM files can also be
+provided for non-confidential guests.
+
+
+Limitations when using IGVM with AMD SEV, SEV-ES and SEV-SNP
+------------------------------------------------------------
+
+IGVM files configure the initial state of the guest using a set of directives.
+Not every directive is supported by every Confidential Guest type. For example,
+AMD SEV does not support encrypted save state regions, therefore setting the
+initial CPU state using IGVM for SEV is not possible. When an IGVM file contains
+directives that are not supported for the active platform, an error is generated
+and the guest launch is aborted.
+
+The table below describes the list of directives that are supported for SEV,
+SEV-ES, SEV-SNP and non-confidential platforms.
+
+.. list-table:: SEV, SEV-ES, SEV-SNP & non-confidential Supported Directives
+ :widths: 35 65
+ :header-rows: 1
+
+ * - IGVM directive
+ - Notes
+ * - IGVM_VHT_PAGE_DATA
+ - ``NORMAL`` zero, measured and unmeasured page types are supported. Other
+ page types result in an error.
+ * - IGVM_VHT_PARAMETER_AREA
+ -
+ * - IGVM_VHT_PARAMETER_INSERT
+ -
+ * - IGVM_VHT_VP_COUNT_PARAMETER
+ - The guest parameter page is populated with the CPU count.
+ * - IGVM_VHT_ENVIRONMENT_INFO_PARAMETER
+ - The ``memory_is_shared`` parameter is set to 1 in the guest parameter
+ page.
+
+.. list-table:: Additional SEV, SEV-ES & SEV_SNP Supported Directives
+ :widths: 25 75
+ :header-rows: 1
+
+ * - IGVM directive
+ - Notes
+ * - IGVM_VHT_MEMORY_MAP
+ - The memory map page is populated using entries from the E820 table.
+ * - IGVM_VHT_REQUIRED_MEMORY
+ - Ensures memory is available in the guest at the specified range.
+
+.. list-table:: Additional SEV-ES & SEV-SNP Supported Directives
+ :widths: 25 75
+ :header-rows: 1
+
+ * - IGVM directive
+ - Notes
+ * - IGVM_VHT_VP_CONTEXT
+ - Setting of the initial CPU state for the boot CPU and additional CPUs is
+ supported with limitations on the fields that can be provided in the
+ VMSA. See below for details on which fields are supported.
+
+Initial CPU state with VMSA
+---------------------------
+
+The initial state of guest CPUs can be defined in the IGVM file for AMD SEV-ES
+and SEV-SNP. The state data is provided as a VMSA structure as defined in Table
+B-4 in the AMD64 Architecture Programmer's Manual, Volume 2 [1].
+
+The IGVM VMSA is translated to CPU state in QEMU which is then synchronized
+by KVM to the guest VMSA during the launch process where it contributes to the
+launch measurement. See :ref:`amd-sev` for details on the launch process and
+guest launch measurement.
+
+It is important that no information is lost or changed when translating the
+VMSA provided by the IGVM file into the VSMA that is used to launch the guest.
+Therefore, QEMU restricts the VMSA fields that can be provided in the IGVM
+VMSA structure to the following registers:
+
+RAX, RCX, RDX, RBX, RBP, RSI, RDI, R8-R15, RSP, RIP, CS, DS, ES, FS, GS, SS,
+CR0, CR3, CR4, XCR0, EFER, PAT, GDT, IDT, LDTR, TR, DR6, DR7, RFLAGS, X87_FCW,
+MXCSR.
+
+When processing the IGVM file, QEMU will check if any fields other than the
+above are non-zero and generate an error if this is the case.
+
+KVM uses a hardcoded GPA of 0xFFFFFFFFF000 for the VMSA. When an IGVM file
+defines initial CPU state, the GPA for each VMSA must match this hardcoded
+value.
+
+Firmware Images with IGVM
+-------------------------
+
+When an IGVM filename is specified for a Confidential Guest Support object it
+overrides the default handling of system firmware: the firmware image, such as
+an OVMF binary should be contained as a payload of the IGVM file and not
+provided as a flash drive or via the ``-bios`` parameter. The default QEMU
+firmware is not automatically populated into the guest memory space.
+
+If an IGVM file is provided along with either the ``-bios`` parameter or pflash
+devices then an error is displayed and the guest startup is aborted.
+
+Running a guest configured using IGVM
+-------------------------------------
+
+To run a guest configured with IGVM you firstly need to generate an IGVM file
+that contains a guest configuration compatible with the platform you are
+targeting.
+
+The ``buildigvm`` tool [2] is an example of a tool that can be used to generate
+IGVM files for non-confidential X86 platforms as well as for SEV, SEV-ES and
+SEV-SNP confidential platforms.
+
+Example using this tool to generate an IGVM file for AMD SEV-SNP::
+
+ buildigvm --firmware /path/to/OVMF.fd --output sev-snp.igvm \
+ --cpucount 4 sev-snp
+
+To run a guest configured with the generated IGVM you need to add an
+``igvm-cfg`` object and refer to it from the ``-machine`` parameter:
+
+Example (for AMD SEV)::
+
+ qemu-system-x86_64 \
+ <other parameters> \
+ -machine ...,confidential-guest-support=sev0,igvm-cfg=igvm0 \
+ -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \
+ -object igvm-cfg,id=igvm0,file=/path/to/sev-snp.igvm
+
+References
+----------
+
+[1] AMD64 Architecture Programmer's Manual, Volume 2: System Programming
+ Rev 3.41
+ https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/24593.pdf
+
+[2] ``buildigvm`` - A tool to build example IGVM files containing OVMF firmware
+ https://github.com/roy-hopkins/buildigvm \ No newline at end of file
diff --git a/docs/system/images.rst b/docs/system/images.rst
index a555117..4370696 100644
--- a/docs/system/images.rst
+++ b/docs/system/images.rst
@@ -30,7 +30,7 @@ Snapshot mode
If you use the option ``-snapshot``, all disk images are considered as
read only. When sectors in written, they are written in a temporary file
created in ``/tmp``. You can however force the write back to the raw
-disk images by using the ``commit`` monitor command (or C-a s in the
+disk images by using the ``commit`` monitor command (or :kbd:`Ctrl+a s` in the
serial console).
.. _vm_005fsnapshots:
diff --git a/docs/system/index.rst b/docs/system/index.rst
index 718e9d3..427b020 100644
--- a/docs/system/index.rst
+++ b/docs/system/index.rst
@@ -38,5 +38,6 @@ or Hypervisor.Framework.
security
multi-process
confidential-guest-support
+ igvm
vm-templating
sriov
diff --git a/docs/system/introduction.rst b/docs/system/introduction.rst
index 338d374..4cd46b5 100644
--- a/docs/system/introduction.rst
+++ b/docs/system/introduction.rst
@@ -81,7 +81,7 @@ may not be optimal for modern systems.
For a non-x86 system where we emulate a broad range of machine types,
the command lines are generally more explicit in defining the machine
-and boot behaviour. You will find often find example command lines in
+and boot behaviour. You will often find example command lines in
the :ref:`system-targets-ref` section of the manual.
While the project doesn't want to discourage users from using the
diff --git a/docs/system/keys.rst.inc b/docs/system/keys.rst.inc
index 59966a3..c28ae1a 100644
--- a/docs/system/keys.rst.inc
+++ b/docs/system/keys.rst.inc
@@ -1,36 +1,37 @@
During the graphical emulation, you can use special key combinations from
-the following table to change modes. By default the modifier is Ctrl-Alt
+the following table to change modes. By default the modifier is :kbd:`Ctrl+Alt`
(used in the table below) which can be changed with ``-display`` suboption
``mod=`` where appropriate. For example, ``-display sdl,
-grab-mod=lshift-lctrl-lalt`` changes the modifier key to Ctrl-Alt-Shift,
-while ``-display sdl,grab-mod=rctrl`` changes it to the right Ctrl key.
+grab-mod=lshift-lctrl-lalt`` changes the modifier key to :kbd:`Ctrl+Alt+Shift`,
+while ``-display sdl,grab-mod=rctrl`` changes it to the right :kbd:`Ctrl` key.
-Ctrl-Alt-f
- Toggle full screen
+.. list-table:: Multiplexer Keys
+ :widths: 10 90
+ :header-rows: 1
-Ctrl-Alt-+
- Enlarge the screen
+ * - Key Sequence
+ - Action
-Ctrl-Alt\--
- Shrink the screen
+ * - :kbd:`Ctrl+Alt+f`
+ - Toggle full screen
-Ctrl-Alt-u
- Restore the screen's un-scaled dimensions
+ * - :kbd:`Ctrl+Alt++`
+ - Enlarge the screen
-Ctrl-Alt-n
- Switch to virtual console 'n'. Standard console mappings are:
+ * - :kbd:`Ctrl+Alt+-`
+ - Shrink the screen
- *1*
- Target system display
+ * - :kbd:`Ctrl+Alt+u`
+ - Restore the screen's un-scaled dimensions
- *2*
- Monitor
+ * - :kbd:`Ctrl+Alt+n`
+ - Switch to virtual console 'n'. Standard console mappings are:
- *3*
- Serial port
+ - *1*: Target system display
+ - *2*: Monitor
+ - *3*: Serial port
+ * - :kbd:`Ctrl+Alt+g`
+ - Toggle mouse and keyboard grab.
-Ctrl-Alt-g
- Toggle mouse and keyboard grab.
-
-In the virtual consoles, you can use Ctrl-Up, Ctrl-Down, Ctrl-PageUp and
-Ctrl-PageDown to move in the back log.
+In the virtual consoles, you can use :kbd:`Ctrl+Up`, :kbd:`Ctrl+Down`, :kbd:`Ctrl+PageUp` and
+:kbd:`Ctrl+PageDown` to move in the back log.
diff --git a/docs/system/linuxboot.rst b/docs/system/linuxboot.rst
index 2328b4a..f7573ab 100644
--- a/docs/system/linuxboot.rst
+++ b/docs/system/linuxboot.rst
@@ -26,5 +26,5 @@ virtual serial port and the QEMU monitor to the console with the
|qemu_system| -kernel bzImage -drive file=rootdisk.img,format=raw \
-append "root=/dev/sda console=ttyS0" -nographic
-Use Ctrl-a c to switch between the serial console and the monitor (see
+Use :kbd:`Ctrl+a c` to switch between the serial console and the monitor (see
:ref:`GUI_keys`).
diff --git a/docs/system/mux-chardev.rst.inc b/docs/system/mux-chardev.rst.inc
index 84ea12c..c87ba31 100644
--- a/docs/system/mux-chardev.rst.inc
+++ b/docs/system/mux-chardev.rst.inc
@@ -1,27 +1,33 @@
During emulation, if you are using a character backend multiplexer
(which is the default if you are using ``-nographic``) then several
commands are available via an escape sequence. These key sequences all
-start with an escape character, which is Ctrl-a by default, but can be
+start with an escape character, which is :kbd:`Ctrl+a` by default, but can be
changed with ``-echr``. The list below assumes you're using the default.
-Ctrl-a h
- Print this help
+.. list-table:: Multiplexer Keys
+ :widths: 20 80
+ :header-rows: 1
-Ctrl-a x
- Exit emulator
+ * - Key Sequence
+ - Action
-Ctrl-a s
- Save disk data back to file (if -snapshot)
+ * - :kbd:`Ctrl+a h`
+ - Print this help
-Ctrl-a t
- Toggle console timestamps
+ * - :kbd:`Ctrl+a x`
+ - Exit emulator
-Ctrl-a b
- Send break (magic sysrq in Linux)
+ * - :kbd:`Ctrl+a s`
+ - Save disk data back to file (if -snapshot)
-Ctrl-a c
- Rotate between the frontends connected to the multiplexer (usually
- this switches between the monitor and the console)
+ * - :kbd:`Ctrl+a t`
+ - Toggle console timestamps
-Ctrl-a Ctrl-a
- Send the escape character to the frontend
+ * - :kbd:`Ctrl+a b`
+ - Send break (magic sysrq in Linux)
+
+ * - :kbd:`Ctrl+a c`
+ - Rotate between the frontends connected to the multiplexer (usually this switches between the monitor and the console)
+
+ * - :kbd:`Ctrl+a Ctrl+a`
+ - Send the escape character to the frontend
diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
index b96a05a..a96d186 100644
--- a/docs/system/target-arm.rst
+++ b/docs/system/target-arm.rst
@@ -71,6 +71,7 @@ Board-specific documentation
.. toctree::
:maxdepth: 1
+ arm/max78000
arm/integratorcp
arm/mps2
arm/musca
diff --git a/docs/system/target-i386.rst b/docs/system/target-i386.rst
index 43b09c7..2374391 100644
--- a/docs/system/target-i386.rst
+++ b/docs/system/target-i386.rst
@@ -37,6 +37,4 @@ OS requirements
~~~~~~~~~~~~~~~
On x86_64 hosts, the default set of CPU features enabled by the KVM
-accelerator require the host to be running Linux v4.5 or newer. Red Hat
-Enterprise Linux 7 is also supported, since the required
-functionality was backported.
+accelerator require the host to be running Linux v4.5 or newer.
diff --git a/docs/system/virtio-net-failover.rst b/docs/system/virtio-net-failover.rst
index 6002dc5..0cc4654 100644
--- a/docs/system/virtio-net-failover.rst
+++ b/docs/system/virtio-net-failover.rst
@@ -26,43 +26,48 @@ and standby devices are not plugged into the same PCIe slot.
Usecase
-------
- Virtio-net standby allows easy migration while using a passed-through fast
- networking device by falling back to a virtio-net device for the duration of
- the migration. It is like a simple version of a bond, the difference is that it
- requires no configuration in the guest. When a guest is live-migrated to
- another host QEMU will unplug the primary device via the PCIe based hotplug
- handler and traffic will go through the virtio-net device. On the target
- system the primary device will be automatically plugged back and the
- net_failover module registers it again as the primary device.
+Virtio-net standby allows easy migration while using a passed-through
+fast networking device by falling back to a virtio-net device for the
+duration of the migration. It is like a simple version of a bond, the
+difference is that it requires no configuration in the guest. When a
+guest is live-migrated to another host QEMU will unplug the primary
+device via the PCIe based hotplug handler and traffic will go through
+the virtio-net device. On the target system the primary device will be
+automatically plugged back and the net_failover module registers it
+again as the primary device.
Usage
-----
- The primary device can be hotplugged or be part of the startup configuration
+The primary device can be hotplugged or be part of the startup configuration
- -device virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:00:6f:55:cc, \
- bus=root2,failover=on
+.. code-block:: shell
- With the parameter failover=on the VIRTIO_NET_F_STANDBY feature will be enabled.
+ -device virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:00:6f:55:cc,bus=root2,failover=on
+
+With the parameter ``failover=on`` the VIRTIO_NET_F_STANDBY feature will be enabled.
+
+.. code-block:: shell
-device vfio-pci,host=5e:00.2,id=hostdev0,bus=root1,failover_pair_id=net1
- failover_pair_id references the id of the virtio-net standby device. This
- is only for pairing the devices within QEMU. The guest kernel module
- net_failover will match devices with identical MAC addresses.
+``failover_pair_id`` references the id of the virtio-net standby device.
+This is only for pairing the devices within QEMU. The guest kernel
+module net_failover will match devices with identical MAC addresses.
Hotplug
-------
- Both primary and standby device can be hotplugged via the QEMU monitor. Note
- that if the virtio-net device is plugged first a warning will be issued that it
- couldn't find the primary device.
+Both primary and standby device can be hotplugged via the QEMU
+monitor. Note that if the virtio-net device is plugged first a warning
+will be issued that it couldn't find the primary device.
Migration
---------
- A new migration state wait-unplug was added for this feature. If failover primary
- devices are present in the configuration, migration will go into this state.
- It will wait until the device unplug is completed in the guest and then move into
- active state. On the target system the primary devices will be automatically hotplugged
- when the feature bit was negotiated for the virtio-net standby device.
+A new migration state wait-unplug was added for this feature. If
+failover primary devices are present in the configuration, migration
+will go into this state. It will wait until the device unplug is
+completed in the guest and then move into active state. On the target
+system the primary devices will be automatically hotplugged when the
+feature bit was negotiated for the virtio-net standby device.