There are some code base and function which are purely KVM specific for
now and we don't have those supports in mshv at the moment but we have plan
for the future. We are doing a feature guard with KVM. For example, KVM has
mp_state, cpu clock support, which we don't have for mshv. In order to build
those code we are making the code base for KVM specific compilation.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
When a total ordering between multiple atomic variables is not required
then use Ordering::Acquire with atomic loads and Ordering::Release with
atomic stores.
This will improve performance as this does not require a memory fence
on x86_64 which Ordering::SeqCst will use.
Add a comment to the code in the vCPU handling code where it operates on
multiple atomics to explain why Ordering::SeqCst is required.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This interface is used by the vCPU thread to delegate responsibility for
handling MMIO/PIO operations and to support different approaches than a
VM exit.
During profiling I found that we were spending 13.75% of the boot CPU
uage acquiring access to the object holding the VmmOps via
ArcSwap::load_full()
13.75% 6.02% vcpu0 cloud-hypervisor [.] arc_swap::ArcSwapAny<T,S>::load_full
|
---arc_swap::ArcSwapAny<T,S>::load_full
|
--13.43%--<hypervisor::kvm::KvmVcpu as hypervisor::cpu::Vcpu>::run
std::sys_common::backtrace::__rust_begin_short_backtrace
core::ops::function::FnOnce::call_once{{vtable-shim}}
std::sys::unix:🧵:Thread:🆕:thread_start
However since the object implementing VmmOps does not need to be mutable
and it is only used from the vCPU side we can change the ownership to
being a simple Arc<> that is passed in when calling create_vcpu().
This completely removes the above CPU usage from subsequent profiles.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The logic to handle AArch64 system event was: SHUTDOWN and RESET were
all treated as RESET.
Now we handle them differently:
- RESET event will trigger Vmm::vm_reboot(),
- SHUTDOWN event will trigger Vmm::vm_shutdown().
Signed-off-by: Michael Zhao <michael.zhao@arm.com>
Now Vcpu::run() returns a boolean value to VcpuManager, indicating
whether the VM is going to reboot (false) or just continue (true).
Moving the handling of hypervisor VCPU run result from Vcpu to
VcpuManager gives us the flexibility to handle more scenarios like
shutting down on AArch64.
Signed-off-by: Michael Zhao <michael.zhao@arm.com>
The snasphot/restore feature is not working because some CPU states are
not properly saved, which means they can't be restored later on.
First thing, we ensure the CPUID is stored so that it can be properly
restored later. The code is simplified and pushed down to the hypervisor
crate.
Second thing, we identify for each vCPU if the Hyper-V SynIC device is
emulated or not. In case it is, that means some specific MSRs will be
set by the guest. These MSRs must be saved in order to properly restore
the VM.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
We turn on that emulation for Windows. Windows does not have KVM's PV
clock, so calling notify_guest_clock_paused results in an error.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
If the user specified a maximum physical bits value through the
`max_phys_bits` option from `--cpus` parameter, the guest CPUID
will be patched accordingly to ensure the guest will find the
right amount of physical bits.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The OneRegister literally means "one (arbitrary) register". Just call it
"Register" instead. There is no need to inherit KVM's naming scheme in
the hypervisor agnostic code.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Run loop in hypervisor needs a callback mechanism to access resources
like guest memory, mmio, pio etc.
VmmOps trait is introduced here, which is implemented by vmm module.
While handling vcpuexits in run loop, this trait allows hypervisor
module access to the above mentioned resources via callbacks.
Signed-off-by: Praveen Paladugu <prapal@microsoft.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The MTRR feature was missing from the CPUID, which is causing the guest
to ignore the MTRR settings exposed through dedicated MSRs.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Similarly as the VM booting process, on AArch64 systems,
the vCPUs should be created before the creation of GIC. This
commit refactors the vCPU save/restore code to achieve the
above-mentioned restoring order.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Since calling `KVM_GET_ONE_REG` before `KVM_VCPU_INIT` will
result in an error: Exec format error (os error 8). This commit
decouples the vCPU init process from `configure_vcpus`. Therefore
in the process of restoring the vCPUs, these vCPUs can be
initialized separately before started.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
The construction of `GICR_TYPER` register will need vCPU states.
Therefore this commit adds methods to extract saved vCPU states
from the cpu manager.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Adds 3 more unit test cases for AArch64:
*save_restore_core_regs
*save_restore_system_regs
*get_set_mpstate
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
This commit ports code from firecracker and refactors the existing
AArch64 code as the preparation for implementing save/restore
AArch64 vCPU, including:
1. Modification of `arm64_core_reg` macro to retrive the index of
arm64 core register and implemention of a helper to determine if
a register is a system register.
2. Move some macros and helpers in `arch` crate to the `hypervisor`
crate.
3. Added related unit tests for above functions and macros.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Inject CPUID leaves for advertising KVM HyperV support when the
"kvm_hyperv" toggle is enabled. Currently we only enable a selection of
features required to boot.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Currently we don't need to do anything to service these exits but when
the synthetic interrupt controller is active an exit will be triggered
to notify the VMM of details of the synthetic interrupt page.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This removes the dependency of the pci crate on the devices crate which
now only contains the device implementations themselves.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
There will be some cases where the implementation of the snapshot()
function from the Snapshottable trait will require to modify some
internal data, therefore we make this possible by updating the trait
definition with snapshot(&mut self).
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Some OS might check for duplicates and bail out, if it can't create a
distinct mapping. According to ACPI 5.0 section 6.1.12, while _UID is
optional, it becomes required when there are multiple devices with the
same _HID.
Signed-off-by: Anatol Belski <ab@php.net>
The support for SGX is exposed to the guest through CPUID 0x12. KVM
passes static subleaves 0 and 1 from the host to the guest, without
needing any modification from the VMM itself.
But SGX also relies on dynamic subleaves 2 through N, used for
describing each EPC section. This is not handled by KVM, which means
the VMM is in charge of setting each subleaf starting from index 2
up to index N, depending on the number of EPC sections.
These subleaves 2 through N are not listed as part of the supported
CPUID entries from KVM. But it's important to set them as long as index
0 and 1 are present and indicate that SGX is supported.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Instead of passing the GuestMemoryMmap directly to the CpuManager upon
its creation, it's better to pass a reference to the MemoryManager. This
way we will be able to know if SGX EPC region along with one or multiple
sections are present.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In order to move the hypervisor specific parts of the VM exit handling
path, we're defining a generic, hypervisor agnostic VM exit enum.
This is what the hypervisor's Vcpu run() call should return when the VM
exit can not be completely handled through the hypervisor specific bits.
For KVM based hypervisors, this means directly forwarding the IO related
exits back to the VMM itself. For other hypervisors that e.g. rely on the
VMM to decode and emulate instructions, this means the decoding itself
would happen in the hypervisor crate exclusively, and the rest of the VM
exit handling would be handled through the VMM device model implementation.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Fix test_vm unit test by using the new abstraction and dropping some
dead code.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
The fd naming is quite KVM specific. Since we're now using the
hypervisor crate abstractions, we can rename those into something more
readable and meaningful. Like e.g. vcpu or vm.
Signed-off-by: Samuel Ortiz <sameo@linux.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>
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>
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>
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>
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>
There are two CPUID leaves for handling CPU topology, 0xb and 0x1f. The
difference between the two is that the 0x1f leaf (Extended Topology
Leaf) supports exposing multiple die packages.
Fixes: #1284
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
The extended topology leaf (0x1f) also needs to have the APIC ID (which
is the KVM cpu ID) set. This mirrors the APIC ID set on the 0xb topology
leaf
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Rather than saving the individual parts into the CpuManager save the
full struct as it now also contains the topology data.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
X86 and AArch64 work in different ways to shutdown a VM.
X86 exit VMM event loop through ACPI device;
AArch64 need to exit from CPU loop of a SystemEvent.
Signed-off-by: Michael Zhao <michael.zhao@arm.com>
