Hi Marc, > -----Original Message----- > From: Marc Zyngier <m...@kernel.org> > Sent: Saturday, September 5, 2020 12:19 AM > To: Jianyong Wu <jianyong...@arm.com> > Cc: netdev@vger.kernel.org; yangbo...@nxp.com; john.stu...@linaro.org; > t...@linutronix.de; pbonz...@redhat.com; sean.j.christopher...@intel.com; > richardcoch...@gmail.com; Mark Rutland <mark.rutl...@arm.com>; > w...@kernel.org; Suzuki Poulose <suzuki.poul...@arm.com>; Steven Price > <steven.pr...@arm.com>; linux-ker...@vger.kernel.org; linux-arm- > ker...@lists.infradead.org; kvm...@lists.cs.columbia.edu; > k...@vger.kernel.org; Steve Capper <steve.cap...@arm.com>; Justin He > <justin...@arm.com>; nd <n...@arm.com> > Subject: Re: [PATCH v14 09/10] doc: add ptp_kvm introduction for arm64 > support > > On Fri, 04 Sep 2020 10:27:43 +0100, > Jianyong Wu <jianyong...@arm.com> wrote: > > > > ptp_kvm implementation depends on hypercall using SMCCC. So we > > introduce a new SMCCC service ID. This doc explain how we define and > > use this new ID. > > > > Signed-off-by: Jianyong Wu <jianyong...@arm.com> > > --- > > Documentation/virt/kvm/arm/ptp_kvm.rst | 72 > > ++++++++++++++++++++++++++ > > 1 file changed, 72 insertions(+) > > create mode 100644 Documentation/virt/kvm/arm/ptp_kvm.rst > > > > diff --git a/Documentation/virt/kvm/arm/ptp_kvm.rst > > b/Documentation/virt/kvm/arm/ptp_kvm.rst > > new file mode 100644 > > index 000000000000..455591e2587a > > --- /dev/null > > +++ b/Documentation/virt/kvm/arm/ptp_kvm.rst > > @@ -0,0 +1,72 @@ > > +.. SPDX-License-Identifier: GPL-2.0 > > + > > +PTP_KVM support for arm64 > > +========================= > > + > > +PTP_KVM is used for time sync between guest and host in a high precison. > > +It needs get wall time and counter value from host and transfer these > > +data to guest via hypercall service. So one more hypercall service > > +should be added. > > + > > +This new SMCCC hypercall will be defined as: > > + > > +* ARM_SMCCC_HYP_KVM_PTP_FUNC_ID: 0xC6000001 > > + > > +As we only support 64-bits ptp_kvm client, so we choose SMC64/HVC64 > > +calling convention. > > This isn't what the code does, as it is explicitly set as an SMC32 service... > Furthermore, we still run 32bit guests, and will do for the foreseeable > future. > Having removed KVM support for 32bit doesn't mean 32bits are gone.
Sorry to have removed arm32 support. It's worthy to add arm32 support in. I will add it next time. Thanks Jianyong > > M. > > -- > Without deviation from the norm, progress is not possible.
