26 строки
1.1 KiB
ReStructuredText
26 строки
1.1 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
|
|
|
|
PTP_KVM support for arm/arm64
|
|
=============================
|
|
|
|
PTP_KVM is used for high precision time sync between host and guests.
|
|
It relies on transferring the wall clock and counter value from the
|
|
host to the guest using a KVM-specific hypercall.
|
|
|
|
* ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID: 0x86000001
|
|
|
|
This hypercall uses the SMC32/HVC32 calling convention:
|
|
|
|
ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID
|
|
============== ======== =====================================
|
|
Function ID: (uint32) 0x86000001
|
|
Arguments: (uint32) KVM_PTP_VIRT_COUNTER(0)
|
|
KVM_PTP_PHYS_COUNTER(1)
|
|
Return Values: (int32) NOT_SUPPORTED(-1) on error, or
|
|
(uint32) Upper 32 bits of wall clock time (r0)
|
|
(uint32) Lower 32 bits of wall clock time (r1)
|
|
(uint32) Upper 32 bits of counter (r2)
|
|
(uint32) Lower 32 bits of counter (r3)
|
|
Endianness: No Restrictions.
|
|
============== ======== =====================================
|