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| author | Paolo Bonzini <pbonzini@redhat.com> | 2021-04-23 14:41:17 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-04-23 14:41:17 +0300 |
| commit | c4f71901d53b6d8a4703389459d9f99fbd80ffd2 (patch) | |
| tree | af8a0c33cec6dfb8a5d5cd7fcef245ab02b12691 /Documentation/virt/kvm/arm/ptp_kvm.rst | |
| parent | fd49e8ee70b306a003323a17bbcc0633f322c135 (diff) | |
| parent | 9a8aae605b80fc0a830cdce747eed48e11acc067 (diff) | |
| download | linux-c4f71901d53b6d8a4703389459d9f99fbd80ffd2.tar.xz | |
Merge tag 'kvmarm-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for Linux 5.13
New features:
- Stage-2 isolation for the host kernel when running in protected mode
- Guest SVE support when running in nVHE mode
- Force W^X hypervisor mappings in nVHE mode
- ITS save/restore for guests using direct injection with GICv4.1
- nVHE panics now produce readable backtraces
- Guest support for PTP using the ptp_kvm driver
- Performance improvements in the S2 fault handler
- Alexandru is now a reviewer (not really a new feature...)
Fixes:
- Proper emulation of the GICR_TYPER register
- Handle the complete set of relocation in the nVHE EL2 object
- Get rid of the oprofile dependency in the PMU code (and of the
oprofile body parts at the same time)
- Debug and SPE fixes
- Fix vcpu reset
Diffstat (limited to 'Documentation/virt/kvm/arm/ptp_kvm.rst')
| -rw-r--r-- | Documentation/virt/kvm/arm/ptp_kvm.rst | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/arm/ptp_kvm.rst b/Documentation/virt/kvm/arm/ptp_kvm.rst new file mode 100644 index 000000000000..aecdc80ddcd8 --- /dev/null +++ b/Documentation/virt/kvm/arm/ptp_kvm.rst @@ -0,0 +1,25 @@ +.. 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. + ============== ======== ===================================== |