__u8 pad2[30];
};
-If the KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL flag is returned from the
-KVM_CAP_XEN_HVM check, it may be set in the flags field of this ioctl.
-This requests KVM to generate the contents of the hypercall page
-automatically; hypercalls will be intercepted and passed to userspace
-through KVM_EXIT_XEN. In this case, all of the blob size and address
-fields must be zero.
+If certain flags are returned from the KVM_CAP_XEN_HVM check, they may
+be set in the flags field of this ioctl:
+
+The KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL flag requests KVM to generate
+the contents of the hypercall page automatically; hypercalls will be
+intercepted and passed to userspace through KVM_EXIT_XEN. In this
+ase, all of the blob size and address fields must be zero.
+
+The KVM_XEN_HVM_CONFIG_EVTCHN_SEND flag indicates to KVM that userspace
+will always use the KVM_XEN_HVM_EVTCHN_SEND ioctl to deliver event
+channel interrupts rather than manipulating the guest's shared_info
+structures directly. This, in turn, may allow KVM to enable features
+such as intercepting the SCHEDOP_poll hypercall to accelerate PV
+spinlock operation for the guest. Userspace may still use the ioctl
+to deliver events if it was advertised, even if userspace does not
+send this indication that it will always do so
No other flags are currently valid in the struct kvm_xen_hvm_config.
struct {
__u64 gfn;
} shared_info;
- __u64 pad[4];
+ struct {
+ __u32 send_port;
+ __u32 type; /* EVTCHNSTAT_ipi / EVTCHNSTAT_interdomain */
+ __u32 flags;
+ union {
+ struct {
+ __u32 port;
+ __u32 vcpu;
+ __u32 priority;
+ } port;
+ struct {
+ __u32 port; /* Zero for eventfd */
+ __s32 fd;
+ } eventfd;
+ __u32 padding[4];
+ } deliver;
+ } evtchn;
+ __u32 xen_version;
+ __u64 pad[8];
} u;
};
KVM_XEN_ATTR_TYPE_UPCALL_VECTOR
Sets the exception vector used to deliver Xen event channel upcalls.
+ This is the HVM-wide vector injected directly by the hypervisor
+ (not through the local APIC), typically configured by a guest via
+ HVM_PARAM_CALLBACK_IRQ.
+
+KVM_XEN_ATTR_TYPE_EVTCHN
+ This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
+ support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It configures
+ an outbound port number for interception of EVTCHNOP_send requests
+ from the guest. A given sending port number may be directed back
+ to a specified vCPU (by APIC ID) / port / priority on the guest,
+ or to trigger events on an eventfd. The vCPU and priority can be
+ changed by setting KVM_XEN_EVTCHN_UPDATE in a subsequent call,
+ but other fields cannot change for a given sending port. A port
+ mapping is removed by using KVM_XEN_EVTCHN_DEASSIGN in the flags
+ field.
+
+KVM_XEN_ATTR_TYPE_XEN_VERSION
+ This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
+ support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It configures
+ the 32-bit version code returned to the guest when it invokes the
+ XENVER_version call; typically (XEN_MAJOR << 16 | XEN_MINOR). PV
+ Xen guests will often use this to as a dummy hypercall to trigger
+ event channel delivery, so responding within the kernel without
+ exiting to userspace is beneficial.
4.127 KVM_XEN_HVM_GET_ATTR
--------------------------
:Returns: 0 on success, < 0 on error
Allows Xen VM attributes to be read. For the structure and types,
-see KVM_XEN_HVM_SET_ATTR above.
+see KVM_XEN_HVM_SET_ATTR above. The KVM_XEN_ATTR_TYPE_EVTCHN
+attribute cannot be read.
4.128 KVM_XEN_VCPU_SET_ATTR
---------------------------
__u64 time_blocked;
__u64 time_offline;
} runstate;
+ __u32 vcpu_id;
+ struct {
+ __u32 port;
+ __u32 priority;
+ __u64 expires_ns;
+ } timer;
+ __u8 vector;
} u;
};
or RUNSTATE_offline) to set the current accounted state as of the
adjusted state_entry_time.
+KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID
+ This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
+ support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It sets the Xen
+ vCPU ID of the given vCPU, to allow timer-related VCPU operations to
+ be intercepted by KVM.
+
+KVM_XEN_VCPU_ATTR_TYPE_TIMER
+ This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
+ support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It sets the
+ event channel port/priority for the VIRQ_TIMER of the vCPU, as well
+ as allowing a pending timer to be saved/restored.
+
+KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR
+ This attribute is available when the KVM_CAP_XEN_HVM ioctl indicates
+ support for KVM_XEN_HVM_CONFIG_EVTCHN_SEND features. It sets the
+ per-vCPU local APIC upcall vector, configured by a Xen guest with
+ the HVMOP_set_evtchn_upcall_vector hypercall. This is typically
+ used by Windows guests, and is distinct from the HVM-wide upcall
+ vector configured with HVM_PARAM_CALLBACK_IRQ.
+
+
4.129 KVM_XEN_VCPU_GET_ATTR
---------------------------
The offsets of the state save areas in struct kvm_xsave follow the contents
of CPUID leaf 0xD on the host.
+4.135 KVM_XEN_HVM_EVTCHN_SEND
+-----------------------------
+
+:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_EVTCHN_SEND
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_irq_routing_xen_evtchn
+:Returns: 0 on success, < 0 on error
+
+
+::
+
+ struct kvm_irq_routing_xen_evtchn {
+ __u32 port;
+ __u32 vcpu;
+ __u32 priority;
+ };
+
+This ioctl injects an event channel interrupt directly to the guest vCPU.
5. The kvm_run structure
========================
#define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0)
#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1)
#define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2)
- #define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 2)
- #define KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL (1 << 3)
+ #define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 3)
+ #define KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL (1 << 4)
+ #define KVM_XEN_HVM_CONFIG_EVTCHN_SEND (1 << 5)
The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG
ioctl is available, for the guest to set its hypercall page.
of the type KVM_IRQ_ROUTING_XEN_EVTCHN are supported, with the priority
field set to indicate 2 level event channel delivery.
+The KVM_XEN_HVM_CONFIG_EVTCHN_SEND flag indicates that KVM supports
+injecting event channel events directly into the guest with the
+KVM_XEN_HVM_EVTCHN_SEND ioctl. It also indicates support for the
+KVM_XEN_ATTR_TYPE_EVTCHN/XEN_VERSION HVM attributes and the
+KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID/TIMER/UPCALL_VECTOR vCPU attributes.
+related to event channel delivery, timers, and the XENVER_version
+interception.
+
8.31 KVM_CAP_PPC_MULTITCE
-------------------------
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