From: Zengruan Ye <yezengruan@xxxxxxxxxx> Introduce a paravirtualization interface for KVM/arm64 to obtain the vcpu is currently running or not. A hypercall interface is provided for the guest to interrogate the hypervisor's support for this interface and the location of the shared memory structures. Signed-off-by: Zengruan Ye <yezengruan@xxxxxxxxxx> --- Documentation/virt/kvm/arm/pvlock.rst | 31 +++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 Documentation/virt/kvm/arm/pvlock.rst diff --git a/Documentation/virt/kvm/arm/pvlock.rst b/Documentation/virt/kvm/arm/pvlock.rst new file mode 100644 index 000000000000..eec0c36edf17 --- /dev/null +++ b/Documentation/virt/kvm/arm/pvlock.rst @@ -0,0 +1,31 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Paravirtualized lock support for arm64 +====================================== + +KVM/arm64 provids some hypervisor service calls to support a paravirtualized +guest obtaining the vcpu is currently running or not. + +Two new SMCCC compatible hypercalls are defined: + +* PV_LOCK_FEATURES: 0xC5000040 +* PV_LOCK_PREEMPTED: 0xC5000041 + +The existence of the PV_LOCK hypercall should be probed using the SMCCC 1.1 +ARCH_FEATURES mechanism before calling it. + +PV_LOCK_FEATURES + ============= ======== ========== + Function ID: (uint32) 0xC5000040 + PV_call_id: (uint32) The function to query for support. + Return value: (int64) NOT_SUPPORTED (-1) or SUCCESS (0) if the relevant + PV-lock feature is supported by the hypervisor. + ============= ======== ========== + +PV_LOCK_PREEMPTED + ============= ======== ========== + Function ID: (uint32) 0xC5000041 + Return value: (int64) NOT_SUPPORTED (-1) or SUCCESS (0) if the IPA of + this vcpu's pv data structure is configured by + the hypervisor. + ============= ======== ========== -- 2.19.1
