Extend hypervisor crd for cortex filtering (#217)

## Background

In [this pull request](cobaltcore-dev/cortex#441) we implemented a cortex filtering pipeline for KVM. This pipeline uses the hypervisor CRD as single source of truth to find out on which hypervisors a vm can be scheduled. To complete this implementation, we need to extend the hypervisor CRD.

## Tasks

Support filtering based on hypervisor type and other capabilities:
- [x] The capabilities struct should be extended to support the hypervisor type. Later, we will probably need to extend this struct further.
- [x] Add fields for supported devices (e.g. video device), cpu modes, and features (for migration filtering) 

Capacity filtering:
- [x] We need a spec + status not only for the size of the host, but also for the currently used capacity. This will be used by cortex to filter out hosts without the required capacity. This scheduling logic can be made more intelligent in the future, by mapping out individual numa cells and including reserved capacity.

Pinned projects:
- [x] Provide a spec to declare pinned projects on this hypervisor.

(Bonus) 
- [x] Add numa cell capacity & allocation information so we can implement numa sensitive initial placement

When finished:
- [x] Ensure backwards compatibility so we can roll this out without any issues

 
## Dependencies

> [!NOTE]
> The scope of this PR is to establish a minimum viable scheduling pipeline in cortex, with the least amount of changes possible. Refactorings of the hypervisor crd spec can follow if needed.

KVM node agent PR: cobaltcore-dev/kvm-node-agent#40

Author: PhilippMatthes

api/v1/hypervisor_types.go

@@ -93,6 +93,12 @@ type HypervisorSpec struct {
 	// Aggregates are used to apply aggregates to the hypervisor.
 	Aggregates []string `json:"aggregates"`
 
+	// +kubebuilder:default:={}
+	// AllowedProjects defines which openstack projects are allowed to schedule
+	// instances on this hypervisor. The values of this list should be project
+	// uuids. If left empty, all projects are allowed.
+	AllowedProjects []string `json:"allowedProjects"`
+
 	// +kubebuilder:default:=true
 	// HighAvailability is used to enable the high availability handling of the hypervisor.
 	HighAvailability bool `json:"highAvailability"`
@@ -190,8 +196,8 @@ type OperatingSystemStatus struct {
 	GardenLinuxFeatures []string `json:"gardenLinuxFeatures,omitempty"`
 }
 
-// Current capabilities reported by libvirt.
-type CapabilitiesStatus struct {
+// Capabilities of the hypervisor as reported by libvirt.
+type Capabilities struct {
 	// +kubebuilder:default:=unknown
 	// The hosts CPU architecture (not the guests).
 	HostCpuArch string `json:"cpuArch,omitempty"`
@@ -201,6 +207,77 @@ type CapabilitiesStatus struct {
 	HostCpus resource.Quantity `json:"cpus,omitempty"`
 }
 
+// Domain capabilities of the hypervisor as reported by libvirt.
+// These details are relevant to check if a VM can be scheduled on the hypervisor.
+type DomainCapabilities struct {
+	// The available domain cpu architecture.
+	// +kubebuilder:default:=unknown
+	Arch string `json:"arch,omitempty"`
+
+	// The supported type of virtualization for domains, such as "ch".
+	// +kubebuilder:default:=unknown
+	HypervisorType string `json:"hypervisorType,omitempty"`
+
+	// Supported devices for domains.
+	//
+	// The format of this list is the device type, and if specified, a specific
+	// model. For example, the take the following xml domain device definition:
+	//
+	// <video supported='yes'>
+	//   <enum name='modelType'>
+	//     <value>nvidia</value>
+	//   </enum>
+	// </video>
+	//
+	// The corresponding entries in this list would be "video" and "video/nvidia".
+	//
+	// +kubebuilder:default:={}
+	SupportedDevices []string `json:"supportedDevices,omitempty"`
+
+	// Supported cpu modes for domains.
+	//
+	// The format of this list is cpu mode, and if specified, a specific
+	// submode. For example, the take the following xml domain cpu definition:
+	//
+	// <mode name='host-passthrough' supported='yes'>
+	//   <enum name='hostPassthroughMigratable'/>
+	// </mode>
+	//
+	// The corresponding entries in this list would be "host-passthrough" and
+	// "host-passthrough/migratable".
+	//
+	// +kubebuilder:default:={}
+	SupportedCpuModes []string `json:"supportedCpuModes,omitempty"`
+
+	// Supported features for domains, such as "sev" or "sgx".
+	//
+	// This is a flat list of supported features, meaning the following xml:
+	//
+	// <features>
+	//   <sev supported='no'/>
+	//   <sgx supported='no'/>
+	// </features>
+	//
+	// Would correspond to the entries "sev" and "sgx" in this list.
+	//
+	// +kubebuilder:default:={}
+	SupportedFeatures []string `json:"supportedFeatures,omitempty"`
+}
+
+// Cell represents a NUMA cell on the hypervisor.
+type Cell struct {
+	// Cell ID.
+	CellID uint64 `json:"cellID"`
+
+	// Auto-discovered resource allocation of all hosted VMs in this cell.
+	// +kubebuilder:validation:Optional
+	Allocation map[string]resource.Quantity `json:"allocation"`
+
+	// Auto-discovered capacity of this cell.
+	// +kubebuilder:validation:Optional
+	Capacity map[string]resource.Quantity `json:"capacity"`
+}
+
 // HypervisorStatus defines the observed state of Hypervisor
 type HypervisorStatus struct {
 	// +kubebuilder:default:=unknown
@@ -216,8 +293,26 @@ type HypervisorStatus struct {
 	// Represents the Hypervisor hosted Virtual Machines
 	Instances []Instance `json:"instances,omitempty"`
 
-	// The capabilities of the hypervisors as reported by libvirt.
-	Capabilities CapabilitiesStatus `json:"capabilities,omitempty"`
+	// Auto-discovered capabilities as reported by libvirt.
+	// +kubebuilder:validation:Optional
+	Capabilities Capabilities `json:"capabilities"`
+
+	// Auto-discovered domain capabilities relevant to check if a VM
+	// can be scheduled on the hypervisor.
+	// +kubebuilder:validation:Optional
+	DomainCapabilities DomainCapabilities `json:"domainCapabilities"`
+
+	// Auto-discovered resource allocation of all hosted VMs.
+	// +kubebuilder:validation:Optional
+	Allocation map[string]resource.Quantity `json:"allocation"`
+
+	// Auto-discovered capacity of the hypervisor.
+	// +kubebuilder:validation:Optional
+	Capacity map[string]resource.Quantity `json:"capacity"`
+
+	// Auto-discovered cells on this hypervisor.
+	// +kubebuilder:validation:Optional
+	Cells []Cell `json:"cells,omitempty"`
 
 	// +kubebuilder:default:=0
 	// Represent the num of instances