builtin-run: Document mode=none for -n/--network

It can be useful to disable all network devices, for example, to remove the
compat warning for the default network device when the guest does not
ini

builtin-run: Document mode=none for -n/--network

It can be useful to disable all network devices, for example, to remove the
compat warning for the default network device when the guest does not
initialize it. This can be done by passing mode=none to the --network
command line option, but without in-depth knowledge of the code, there is
no way for the user to know this. Update the help message for -n/--network
to explain what mode=none does.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20230907171655.6996-3-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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Apply scaling down the calculated guest ram size to the number of pages

Calculate the guest ram size based a ratio proportional to the
number of pages available, rather than the amount of memory
ava

Apply scaling down the calculated guest ram size to the number of pages

Calculate the guest ram size based a ratio proportional to the
number of pages available, rather than the amount of memory
available in bytes, in the host. This is to ensure that the
result is always page-aligned.

If the result of get_ram_size() isn't aligned to the host page
size, it triggers an error in __kvm_set_memory_region(), called
via the KVM_SET_USER_MEMORY_REGION ioctl, which requires the size
to be page-aligned.

Fixes: 18bd8c3bd2a7 ("kvm tools: Don't use all of host RAM for guests by default")
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20230717121232.3559948-4-tabba@google.com
Signed-off-by: Will Deacon <will@kernel.org>

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Factor out getting the number of physical memory host pages

Factor out getting the number of physical pages available for the
host into a separate function. This will be used in a subsequent
patch.

Factor out getting the number of physical memory host pages

Factor out getting the number of physical pages available for the
host into a separate function. This will be used in a subsequent
patch.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20230717121232.3559948-3-tabba@google.com
Signed-off-by: Will Deacon <will@kernel.org>

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Factor out getting the host page size

Factor out getting the page size of the host into a separate
function. This will be used in a subsequent patch.

No functional change intended.

Signed-off-by:

Factor out getting the host page size

Factor out getting the page size of the host into a separate
function. This will be used in a subsequent patch.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20230717121232.3559948-2-tabba@google.com
Signed-off-by: Will Deacon <will@kernel.org>

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Add --loglevel argument for the run command

Add --loglevel command line argument, with the possible values of 'error',
'warning', 'info' or 'debug' to control what messages kvmtool displays. The
arg

Add --loglevel argument for the run command

Add --loglevel command line argument, with the possible values of 'error',
'warning', 'info' or 'debug' to control what messages kvmtool displays. The
argument functions similarly to the Linux kernel parameter, when lower
verbosity levels hide all message with a higher verbosity (for example,
'warning' hides info and debug messages, allows warning and error
messsages).

The default level is 'info', to match the current behaviour. --debug has
been kept as a legacy option, which might be removed in the future.

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230707151119.81208-5-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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Replace printf/fprintf with pr_* macros

To prepare for allowing finer control over the messages that kvmtool
displays, replace printf() and fprintf() with the pr_* macros.

Minor changes were made t

Replace printf/fprintf with pr_* macros

To prepare for allowing finer control over the messages that kvmtool
displays, replace printf() and fprintf() with the pr_* macros.

Minor changes were made to fix coding style issues that were pet peeves for
the author. And use pr_err() in kvm_cpu__init() instead of pr_warning() for
fatal errors.

Also, fix the message when printing the exit code for KVM_EXIT_UNKNOWN by
removing the '0x' part, because it's printing a decimal number, not a
hexadecimal one (the format specifier is %llu, not %llx).

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230707151119.81208-3-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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option parsing: fix type of empty .argh parameter

The "force-pci" and "virtio-legacy" option definitions were using '\0'
to initialise an unused ".argh" member, even though this is a string.
This tr

option parsing: fix type of empty .argh parameter

The "force-pci" and "virtio-legacy" option definitions were using '\0'
to initialise an unused ".argh" member, even though this is a string.
This triggers warnings with some compilers like clang.
Also, for some odd reason, the .argh member was not named explicitly in
the option helper macros initialisation, which made this problem harder
to locate.

Sanitise the option macros by always using designated initialisers for
each member, and use the correct empty string for the "force-pci" and
"virtio-legacy" options.

This fixes warnings (promoted to errors) when compiling with clang.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20230525144827.679651-2-andre.przywara@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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Add virtio-transport option and deprecate force-pci and virtio-legacy.

This is a follow-up patch for [0] which proposed the --force-pci option
for riscv. As per the discussion it was concluded to ad

Add virtio-transport option and deprecate force-pci and virtio-legacy.

This is a follow-up patch for [0] which proposed the --force-pci option
for riscv. As per the discussion it was concluded to add virtio-tranport
option taking in four options (pci, pci-legacy, mmio, mmio-legacy).

With this change force-pci and virtio-legacy are both deprecated and
arm's default transport changes from MMIO to PCI as agreed in [0].
This is also true for riscv.

Nothing changes for other architectures.

[0]: https://lore.kernel.org/all/20230118172007.408667-1-rkanwal@rivosinc.com/

Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com>
Link: https://lore.kernel.org/r/20230320143344.404307-1-rkanwal@rivosinc.com
Signed-off-by: Will Deacon <will@kernel.org>

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virtio: Add support for modern virtio-pci

Add support for modern virtio-pci implementation (based on the 1.0 virtio
spec). We add a new transport, alongside MMIO and PCI-legacy. This is now
the defa

virtio: Add support for modern virtio-pci

Add support for modern virtio-pci implementation (based on the 1.0 virtio
spec). We add a new transport, alongside MMIO and PCI-legacy. This is now
the default when selecting PCI, but users can still select the legacy
transport for all virtio devices by passing "--virtio-legacy" on the
command-line.

The main change in modern PCI is the way we address virtqueues, using
64-bit values instead of PFNs. To keep the queue configuration atomic the
device also gets a "queue enable" register. Configuration is also made
extensible by more feature bits and PCI capabilities. Scalability is
improved as well, as devices can have notification registers for each
virtqueue on separate pages. However this implementation keeps a single
notification register.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Link: https://lore.kernel.org/r/20220701142434.75170-9-jean-philippe.brucker@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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arm64: Allow the user to specify the RAM base address

Allow the user to specify the RAM base address by using -m/--mem size@addr
command line argument. The base address must be above 2GB, as to not

arm64: Allow the user to specify the RAM base address

Allow the user to specify the RAM base address by using -m/--mem size@addr
command line argument. The base address must be above 2GB, as to not
overlap with the MMIO I/O region.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-and-Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220616134828.129006-13-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin_run: Allow standard size specifiers for memory

Allow the user to use the standard B (bytes), K (kilobytes), M (megabytes),
G (gigabytes), T (terabytes) and P (petabytes) suffixes for memory

builtin_run: Allow standard size specifiers for memory

Allow the user to use the standard B (bytes), K (kilobytes), M (megabytes),
G (gigabytes), T (terabytes) and P (petabytes) suffixes for memory size.
When none are specified, the default is megabytes.

Also raise an error if the guest specifies 0 as the memory size, instead
of treating it as uninitialized, as kvmtool has done so far.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-and-Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220616134828.129006-9-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin-run: Add arch hook to validate VM configuration

Architectures are free to set their own command line options. Add an
architecture specific hook to validate these options.

For now, the hook

builtin-run: Add arch hook to validate VM configuration

Architectures are free to set their own command line options. Add an
architecture specific hook to validate these options.

For now, the hook does nothing, but it will be used in later patches.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-and-Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220616134828.129006-5-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin-run: Rework RAM size validation

host_ram_size() uses sysconf() to calculate the available ram, and
sysconf() can fail. When that happens, host_ram_size() returns 0. kvmtool
warns the user wh

builtin-run: Rework RAM size validation

host_ram_size() uses sysconf() to calculate the available ram, and
sysconf() can fail. When that happens, host_ram_size() returns 0. kvmtool
warns the user when the configured VM ram size exceeds the size of the
host's memory, but doesn't take into account that host_ram_size() can
return 0. If the function returns zero, skip the warning.

Since this can only happen when the user sets the memory size (via the
-m/--mem command line argument), skip the check entirely if the user hasn't
set it. Move the check to kvm_run_validate_cfg(), as it checks for valid
user configuration.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-and-Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220616134828.129006-4-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin-run: Always use RAM size in bytes

The user can specify the virtual machine memory size in MB, which is saved
in cfg->ram_size. kvmtool validates it against the host memory size,
converted fr

builtin-run: Always use RAM size in bytes

The user can specify the virtual machine memory size in MB, which is saved
in cfg->ram_size. kvmtool validates it against the host memory size,
converted from bytes to MB. ram_size is then converted to bytes, and this
is how it is used throughout the rest of kvmtool.

To avoid any confusion about the unit of measurement, especially once the
user is allowed to specify the unit of measurement, always use ram_size in
bytes.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-and-Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220616134828.129006-3-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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Use MB for megabytes consistently

The help text for the -m/--mem argument states that the guest memory size
is in MiB (mebibyte). MiB is the same thing as MB (megabyte), and indeed
this is how MB is

Use MB for megabytes consistently

The help text for the -m/--mem argument states that the guest memory size
is in MiB (mebibyte). MiB is the same thing as MB (megabyte), and indeed
this is how MB is used throughout kvmtool.

Replace MiB with MB, so people don't get the wrong idea and start
believing that for kvmtool a MB is 10^6 bytes instead of 2^20.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-and-Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220616134828.129006-2-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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Make --no-pvtime command argument arm specific

The stolen time option is available only for aarch64 and is enabled by
default. Move the option that disables stolen time functionality in the
arch spe

Make --no-pvtime command argument arm specific

The stolen time option is available only for aarch64 and is enabled by
default. Move the option that disables stolen time functionality in the
arch specific path.

Signed-off-by: Sebastian Ene <sebastianene@google.com>
Link: https://lore.kernel.org/r/20220324154304.2572891-1-sebastianene@google.com
Signed-off-by: Will Deacon <will@kernel.org>

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Add --no-pvtime command line argument

The command line argument disables the stolen time functionality when is
specified.

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Seb

Add --no-pvtime command line argument

The command line argument disables the stolen time functionality when is
specified.

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Link: https://lore.kernel.org/r/20220313161949.3565171-4-sebastianene@google.com
Signed-off-by: Will Deacon <will@kernel.org>

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Add --nodefaults command line argument

kvmtool attempts to make it as easier as possible on the user to run a VM
by doing a few different things: it tries to create a rootfs filesystem in
a director

Add --nodefaults command line argument

kvmtool attempts to make it as easier as possible on the user to run a VM
by doing a few different things: it tries to create a rootfs filesystem in
a directory if not disk or initrd is set by the user, and it adds various
parameters to the kernel command line based on the VM configuration
options.

While this is generally very useful, today there isn't any way for the user
to prohibit this behaviour, even though there are situations where this
might not be desirable, like, for example: loading something which is not a
kernel (kvm-unit-tests comes to mind, which expects test parameters on the
kernel command line); the kernel has a built-in initramfs and there is no
need to generate the root filesystem, or it not possible; and what is
probably the most important use case, when the user is actively trying to
break things for testing purposes.

Add a --nodefaults command line argument which disables everything that
cannot be disabled via another command line switch. The purpose of this
knob is not to disable the default options for arguments that can be set
via the kvmtool command line, but rather to inhibit behaviour that cannot
be disabled otherwise.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210923144505.60776-8-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin-run: Move kernel command line generation to a separate function

The real kernel command line is gradually generated in kvm_cmd_run_init()
and it is interspersed with the initialization code.

builtin-run: Move kernel command line generation to a separate function

The real kernel command line is gradually generated in kvm_cmd_run_init()
and it is interspersed with the initialization code. This means that both
the code that generates the command line and the rest of the code is
unnecessarily difficult to follow and to modify. Move the code that
generates the command line to one function, to make it easier to
understand, and to declutter kvm_cmd_run_init().

No functional change intended.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210923144505.60776-7-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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Use kvm->nr_disks instead of kvm->cfg.image_count

A user can specify multiple disk images using the --disk/-d argument. The
callback for the argument ends up in
disk/core.c::calling disk_img_name_pa

Use kvm->nr_disks instead of kvm->cfg.image_count

A user can specify multiple disk images using the --disk/-d argument. The
callback for the argument ends up in
disk/core.c::calling disk_img_name_parser(), which increments
kvm->cfg.image_count for each disk image.

Immediately after parsing the arguments in kvm_cmd_run_init(),
kvm->nr_disks is set to kvm->cfg.image_count, effectively making
kvm->nr_disks an alias for kvm->cfg.image_count, as image_count is never
changed afterward.

Later on, the core disk code uses kvm->cfg.image_count when opening all the
disk images, but kvm->nr_disks when closing them, which is inconsistent,
but technically correct since they represent the same thing and have the
same value.

Let's remove all this confusing usage and use only kvm->nr_disks to
represent the number of disk images specified by the user.

While this technically means that kvmtool now supports up to INT_MAX disk
images, in practice this is limited by MAX_DISK_IMAGES, which is equal to
four. Which means there are no functional changes.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210923144505.60776-6-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin-run: Abstract argument validation into a separate function

kvm_cmd_run_init() is a complex function which parses the command line
arguments, configures various aspects of a VM (the size of t

builtin-run: Abstract argument validation into a separate function

kvm_cmd_run_init() is a complex function which parses the command line
arguments, configures various aspects of a VM (the size of the RAM, the
number of CPUs, the network, the active console, the kernel command line,
creates a custom rootfs, etc), and after the recent patches, also does a
few checks against mutually exclusive kvmtool arguments.

Make the function just that little bit easier to read by moving the
argument validation into a separate function.

No functional change intended.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210923144505.60776-5-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin-run: Do not attempt to find vmlinux if --firmware

kvm->vmlinux is used by symbol.c on x86 to translate a PC address to a
kernel symbol when kvmtool exits unexpectedly. When the --firmware ar

builtin-run: Do not attempt to find vmlinux if --firmware

kvm->vmlinux is used by symbol.c on x86 to translate a PC address to a
kernel symbol when kvmtool exits unexpectedly. When the --firmware argument
is used, a kernel image is not used for the VM, and the vmlinux file has no
relevance in this case.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210923144505.60776-4-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin-run: Warn when ignoring initrd because --firmware was specified

The firmware image is copied into the guest memory with the arch specific
function kvm__load_firmware() in kvm__init(). That f

builtin-run: Warn when ignoring initrd because --firmware was specified

The firmware image is copied into the guest memory with the arch specific
function kvm__load_firmware() in kvm__init(). That function ignores the
initrd file, if the user specified one. Let the user know that the file is
ignored by KVM and the --initrd argument does nothing with --firmware.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210923144505.60776-3-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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builtin-run: Treat specifying both --kernel and --firmware as an error

If the user specifies both the --kernel and the --firmware arguments,
--firmware takes precedence and --kernel is silently igno

builtin-run: Treat specifying both --kernel and --firmware as an error

If the user specifies both the --kernel and the --firmware arguments,
--firmware takes precedence and --kernel is silently ignored. Since kvmtool
has no way of knowing what the user really intended, and guessing that
--firmware is the right argument might prove to be quite unexpected for the
user, be vocal about the incompatibility and refuse to create the VM.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210923144505.60776-2-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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virtio: add support for vsock

The "run" command accepts a new option (--vsock <cid>) which specify the
guest CID. For instance:

$ lkvm run --kernel ./bzImage --disk test --vsock 3

One can easily

virtio: add support for vsock

The "run" command accepts a new option (--vsock <cid>) which specify the
guest CID. For instance:

$ lkvm run --kernel ./bzImage --disk test --vsock 3

One can easily test by: https://github.com/stefanha/nc-vsock.

In the guest:

# modprobe vsock
# nc-vsock -l 1234

In the host:

# modprobe vhost_vsock
# nc-vsock 3 1234

This patch comes from the early submission of G. Campana. On this basis,
I fixed the compilation errors and runtime crashes. Thanks for the work
done by G. Campana.
https://patchwork.kernel.org/patch/9542313/

Signed-off-by: G. Campana <gcampana+kvm@quarkslab.com>
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20200915094402.107988-1-tianjia.zhang@linux.alibaba.com
Signed-off-by: Will Deacon <will@kernel.org>

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