Each virtio thread was reading/draining the pause_evt pipe when
detecting the associated event. Problem is, when a virtio device has
multiple threads, they all share the same pause_evt pipe, which can
prevent some threads from receiving the event. If the first thread to
catch the event is quickly clearing the pipe, some other threads might
simply miss the event and they will not enter the "paused" state as
expected.
This is a behavior that was spotted with virtio-net as it usually uses
2 threads by default (1 for TX/RX queues and 1 for the control queue).
The way to solve this issue is by letting each thread drain the pipe
during the resume codepath, that is after the thread has been unparked.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Because we don't want the guest to miss any event triggered by the
emulation of devices, it is important to resume all vCPUs before we can
resume the DeviceManager with all its associated devices.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
We need consistency between pause/resume and snapshot/restore
operations. The symmetrical behavior of pausing/snapshotting
and restoring/resuming has been introduced recently, and we must
now ensure that no matter if we're using pause/resume or
snapshot/restore features, the resulting VM should be running in
the exact same way.
That's why the vCPU state is now stored upon VM pausing. The snapshot
operation being a simple serialization of the previously saved state.
The same way, the vCPU state is now restored upon VM resuming. The
restore operation being a simple deserialization of the previously
restored state.
It's interesting to note that this patch ensures time consistency from a
guest perspective, no matter which clocksource is being used. From a
previous patch, the KVM clock was saved/restored upon VM pause/resume.
We now have the same behavior for TSC, as the TSC from the vCPUs are
saved/restored upon VM pause/resume too.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Instead of calling the resume() function from the CpuManager, which
involves more than what is needed from the shutdown codepath, and
potentially ends up with a deadlock, we replace it with a subset.
The full resume operation is reserved for a VM that has been paused.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
We want each Vcpu to store the vCPU state upon VM pausing. This is the
reason why we need to explicitly implement the Pausable trait for the
Vcpu structure.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
When set_user_memory_region was moved to hypervisor crate, it was turned
into a safe function that wrapped around an unsafe call. All but one
call site had the safety statements removed. But safety statement was
not moved inside the wrapper function.
Add the safety statement back to help reasoning in the future. Also
remove that one last instance where the safety statement is not needed .
No functional change.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
That removes one more KVM-ism in VMM crate.
Note that there are more KVM specific code in those files to be split
out, but we're not at that stage yet.
No functional change.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Add a simple test to check that the data from the counters matches what
is expected and that the value of the counters increases after an
operation that will hit all counters.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Collate the virtio device counters in DeviceManager for each device that
exposes any and expose it through the recently added HTTP API.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The counters are a hash of device name to hash of counter name to u64
value. Currently the API is only implemented with a stub that returns an
empty set of counters.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Through the counters() function on the trait expose the accumulated
counters.
TEST=Observe that the counters from the VM match those from the tap on
the host (RX-TX inverted) and inside the guest (non inverted.)
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The counters are a hash of counter name to (wrapping) u64 value. The
interpretation layer is responsible for converting this data into a
rate.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This corresponds to QEMU's 63659fe74e76f5c52854 commit.
the setattr code uses both fchmod and fchmodat in different cases,
however we only had fchmodat in the whitelist.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
The structure is tightly coupled with KVM. It uses KVM specific
structures and calls. Add Kvm prefix to it.
Microsoft hypervisor will implement its own interrupt group(s) later.
No functional change intended.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Now that the VMM uses KVM_KVMCLOCK_CTRL from the KVM API, it must be
added to the seccomp filters list.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Through the newly added API notify_guest_clock_paused(), this patch
improves the vCPU pause operation by letting the guest know that each
vCPU is being paused. This is important to avoid soft lockups detection
from the guest that could happen because the VM has been paused for more
than 20 seconds.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
It's important that on restore path, the CpuManager's vCPU gets filled
with each new vCPU that is being created. In order to cover both boot
and restore paths, the list is being filled from the common function
create_vcpu().
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Now that the VMM uses both KVM_GET_CLOCK and KVM_SET_CLOCK from the KVM
API, they must be added to the seccomp filters list.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to maintain correct time when doing pause/resume and
snapshot/restore operations, this patch stores the clock value
on pause, and restore it on resume. Because snapshot/restore
expects a VM to be paused before the snapshot and paused after
the restore, this covers the migration use case too.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
When a request is made to increase the number of vCPUs in the VM attempt
to reuse any previously removed (and hence inactive) vCPUs before
creating new ones.
This ensures that the APIC ID is not reused for a different KVM vCPU
(which is not allowed) and that the APIC IDs are also sequential.
The two key changes to support this are:
* Clearing the "kill" bit on the old vCPU state so that it does not
immediately exit upon thread recreation.
* Using the length of the vcpus vector (the number of allocated vcpus)
rather than the number of active vCPUs (.present_vcpus()) to determine
how many should be created.
This change also introduced some new info!() debugging on the vCPU
creation/removal path to aid further development in the future.
TEST=Expanded test_cpu_hotplug test.
Fixes: #1338
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
After the vCPU has been ejected and the thread shutdown it is useful to
clear the "kill" flag so that if the vCPU is reused it does not
immediately exit upon thread recreation.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
These messages are intended to be useful to support debugging related to
vCPU hotplug/unplug issues.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Now that snapshot/restore is symmetrical, that is the VM must be paused
before it is snapshot and it must be resumed after it's been restored,
the integration test is updated accordingly.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The same way the VM and the vCPUs are restored in a paused state, all
devices associated with the device manager must be restored in the same
paused state.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Because we need to pause the VM before it is snapshot, it should be
restored in a paused state to keep the sequence symmetrical. That's the
reason why the state machine regarding the valid VM's state transition
needed to be updated accordingly.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
To follow a symmetrical model, and avoid potential race conditions, it's
important to restore a previously snapshot VM in a "paused" state.
The snapshot operation being valid only if the VM has been previously
paused.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
When the hypervisor crate was introduced, a few places that handled
errors were commented out in favor of unwrap, but that's bad practice.
Restore proper error handling in those places in this patch.
We cannot use from_raw_os_error anymore because it is wrapped deep under
hypervisor crate. Create new custom errors instead.
Fixes: e4dee57e81 ("arch, pci, vmm: Initial switch to the hypervisor crate")
Signed-off-by: Wei Liu <liuwe@microsoft.com>
This commit fixes some warnings introduced in the previous
hyperviosr crate PR.Removed some unused variables from arch/aarch64
module.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Start moving the vmm, arch and pci crates to being hypervisor agnostic
by using the hypervisor trait and abstractions. This is not a complete
switch and there are still some remaining KVM dependencies.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Implement the vCPU state getter and setter separately from the initial
KVM Hypervisor trait implementation, mostly for readability purposes.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
For each of the traits we are defining kvm related structures
and add the trait implementation to the structs. For more information
please see the kvm-ioctls and kvm-bindings crate.
This is a standalone implementation that does not include the switch of
the Cloud-Hypervisor vmm and arch crates to it.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
As the only hypervisor that Cloud-Hypervisor supports is KVM, the
Hypervisor trait accomodates for the upcoming KVM implementation.
This trait will be instanciated at build time through hypervisor
specific features, i.e. it's not aiming at run-time selection of
hypervisors for Cloud-Hypervisor.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This VM trait should be implemented by each underlying hypervisor.
Previously created hypervisor object should create the VM based on
already selected hypervisor. This is just the trait definition. For each
of supported hypervisor we need to implement the trait. Later we will
implement this trait for KVM and then Microsoft Hyper-V.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This Vcpu trait should be implemented by each underlying hypervisor.
Previously created hypervisor object should create the VM based on
already selected hypervisor and Vm object should create this vcpu
object based on same hyperviosr. Each of this object should be
referenced by trait object i.e <dyn Vcpu>.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
