@@ -7,19 +7,29 @@ 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
+``ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID``
+----------------------------------------
-This hypercall uses the SMC32/HVC32 calling convention:
+Retrieve current time information for the specific counter. There are no
+endianness restrictions.
-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.
- ============== ======== =====================================
++---------------------+-------------------------------------------------------+
+| Presence: | Optional |
++---------------------+-------------------------------------------------------+
+| Calling convention: | HVC32 |
++---------------------+----------+--------------------------------------------+
+| Function ID: | (uint32) | 0x86000001 |
++---------------------+----------+----+---------------------------------------+
+| Arguments: | (uint32) | R1 | ``KVM_PTP_VIRT_COUNTER (0)`` |
+| | | +---------------------------------------+
+| | | | ``KVM_PTP_PHYS_COUNTER (1)`` |
++---------------------+----------+----+---------------------------------------+
+| Return Values: | (int32) | R0 | ``NOT_SUPPORTED (-1)`` on error, else |
+| | | | upper 32 bits of wall clock time |
+| +----------+----+---------------------------------------+
+| | (uint32) | R1 | Lower 32 bits of wall clock time |
+| +----------+----+---------------------------------------+
+| | (uint32) | R2 | Upper 32 bits of counter |
+| +----------+----+---------------------------------------+
+| | (uint32) | R3 | Lower 32 bits of counter |
++---------------------+----------+----+---------------------------------------+
The PTP hypercall documentation doesn't produce the best-looking table when formatting in HTML as all of the return value definitions end up on the same line. Reformat the PTP hypercall documentation to follow the formatting used by hypercalls.rst. Signed-off-by: Will Deacon <will@kernel.org> --- Documentation/virt/kvm/arm/ptp_kvm.rst | 38 ++++++++++++++++---------- 1 file changed, 24 insertions(+), 14 deletions(-)