For most use cases, there is no need to create multiple VFIO containers
as it causes unwanted behaviors. Especially when passing multiple
devices from the same IOMMU group, we need to use the same container so
that it can properly list the groups that have been already opened. The
correct logic was already there in vfio-ioctls, but it was incorrectly
used from our VMM implementation.
For the special case where we put a VFIO device behind a vIOMMU, we must
create one container per device, as we need to control the DMA mappings
per device, which is performed at the container level. Because we must
keep one container per device, the vIOMMU use case prevents multiple
devices attached to the same IOMMU group to be passed through the VM.
But this is a limitation that we are fine with, especially since the
vIOMMU doesn't let us group multiple devices in the same group from a
guest perspective.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
When a pty is resized (using the TIOCSWINSZ ioctl -- see ioctl_tty(2)),
the kernel will send a SIGWINCH signal to the pty's foreground process
group to notify it of the resize. This is the only way to be notified
by the kernel of a pty resize.
We can't just make the cloud-hypervisor process's process group the
foreground process group though, because a process can only set the
foreground process group of its controlling terminal, and
cloud-hypervisor's controlling terminal will often be the terminal the
user is running it in. To work around this, we fork a subprocess in a
new process group, and set its process group to be the foreground
process group of the pty. The subprocess additionally must be running
in a new session so that it can have a different controlling
terminal. This subprocess writes a byte to a pipe every time the pty
is resized, and the virtio-console device can listen for this in its
epoll loop.
Alternatives I considered were to have the subprocess just send
SIGWINCH to its parent, and to use an eventfd instead of a pipe.
I decided against the signal approach because re-purposing a signal
that has a very specific meaning (even if this use was only slightly
different to its normal meaning) felt unclean, and because it would
have required using pidfds to avoid race conditions if
cloud-hypervisor had terminated, which added complexity. I decided
against using an eventfd because using a pipe instead allows the child
to be notified (via poll(2)) when nothing is reading from the pipe any
more, meaning it can be reliably notified of parent death and
terminate itself immediately.
I used clone3(2) instead of fork(2) because without
CLONE_CLEAR_SIGHAND the subprocess would inherit signal-hook's signal
handlers, and there's no other straightforward way to restore all signal
handlers to their defaults in the child process. The only way to do
it would be to iterate through all possible signals, or maintain a
global list of monitored signals ourselves (vmm:vm::HANDLED_SIGNALS is
insufficient because it doesn't take into account e.g. the SIGSYS
signal handler that catches seccomp violations).
Signed-off-by: Alyssa Ross <hi@alyssa.is>
This prepares us to be able to handle console resizes in the console
device's epoll loop, which we'll have to do if the output is a pty,
since we won't get SIGWINCH from it.
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Musl often uses mmap to allocate memory where Glibc would use brk.
This has caused seccomp violations for me on the API and signal
handling threads.
Signed-off-by: Alyssa Ross <hi@alyssa.is>
error: all if blocks contain the same code at the end
--> vmm/src/memory_manager.rs:884:9
|
884 | / Ok(mm)
885 | | }
| |_________^
Signed-off-by: Bo Chen <chen.bo@intel.com>
This concept ends up being broken with multiple types on input connected
e.g. console on TTY and serial on PTY. Already the code for checking for
injecting into the serial device checks that the serial is configured.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Introduce a common solution for spawning the virtio threads which will
make it easier to add the panic handling.
During this effort I discovered that there were no seccomp filters
registered for the vhost-user-net thread nor the vhost-user-block
thread. This change also incorporates basic seccomp filters for those as
part of the refactoring.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Current AArch64 power button is only for device tree using a PL061
GPIO controller device. Since AArch64 now supports ACPI, this
commit extend the power button on AArch64 to:
- Using GED for ACPI+UEFI boot.
- Using PL061 for device tree boot.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
These statements are useful for understanding the cause of reset or
shutdown of the VM and are not spammy so should be included at info!()
level.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Despite setting up a dedicated thread for signal handling, we weren't
making sure that the signals we were listening for there were actually
dispatched to the right thread. While the signal-hook provides an
iterator API, so we can know that we're only processing the signals
coming out of the iterator on our signal handling thread, the actual
signal handling code from signal-hook, which pushes the signals onto
the iterator, can run on any thread. This can lead to seccomp
violations when the signal-hook signal handler does something that
isn't allowed on that thread by our seccomp policy.
To reproduce, resize a terminal running cloud-hypervisor continuously
for a few minutes. Eventually, the kernel will deliver a SIGWINCH to
a thread with a restrictive seccomp policy, and a seccomp violation
will trigger.
As part of this change, it's also necessary to allow rt_sigreturn(2)
on the signal handling thread, so signal handlers are actually allowed
to run on it. The fact that this didn't seem to be needed before
makes me think that signal handlers were almost _never_ actually
running on the signal handling thread.
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Move the processing of the input from stdin, PTY or file from the VMM
thread to the existing virtio-console thread. The handling of the resize
of a virtio-console has not changed but the name of the struct used to
support that has been renamed to reflect its usage.
Fixes: #3060
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Downcasting of GicDevice trait might fail. Therefore we try to
downcast the trait first and only if the downcasting succeeded we
can then use the object to call methods. Otherwise, do nothing and
log the failure.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
This commit implements the GIC (including both GICv3 and GICv3ITS)
Pausable trait. The pause of device manager will trigger a "pause"
of GIC, where we flush GIC pending tables and ITS tables to the
guest RAM.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
This prevents the boot of the guest kernel from being blocked by
blocking I/O on the serial output since the data will be buffered into
the SerialBuffer.
Fixes: #3004
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Introduce a dynamic buffer for storing output from the serial port. The
SerialBuffer implements std::io::Write and can be used in place of the
direct output for the serial device.
The internals of the buffer is a vector that grows dynamically based on
demand up to a fixed size at which point old data will be overwritten.
Currently the buffer is only flushed upon writes.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The rust-vmm crates we're pulling from git have renamed their main
branches. We need to update the branch names we're giving to Cargo,
or people who don't have these dependencies cached will get errors
like this when trying to build:
error: failed to get `vm-fdt` as a dependency of package `arch v0.1.0 (/home/src/cloud-hypervisor/arch)`
Caused by:
failed to load source for dependency `vm-fdt`
Caused by:
Unable to update https://github.com/rust-vmm/vm-fdt?branch=master#031572a6
Caused by:
object not found - no match for id (031572a6edc2f566a7278f1e17088fc5308d27ab); class=Odb (9); code=NotFound (-3)
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Remove the indirection of a dispatch table and simply use the enum as
the event data for the events.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Use two separate events for the console and serial PTY and then drive
the handling of the inputs on the PTY separately. This results in the
correct behaviour when both console and serial are attached to the PTY
as they are triggered separately on the epoll so events are not lost.
Fixes: #3012
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Check the config to find out which device is attached to the tty and
then send the input from the user into that device (serial or
virtio-console.)
Fixes: #3005
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
vhdx_sync.rs in block_util implements traits to represent the vhdx
crate as a supported block device in the cloud hypervisor. The vhdx
is added to the block device list in device_manager.rs at the vmm
crate so that it can automatically detect a vhdx disk and invoke the
corresponding crate.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: Fazla Mehrab <akm.fazla.mehrab@intel.com>
