Re: [PATCH v1 2/3] x86/xen/time: setup vcpu 0 time info page

From: Andy Lutomirski
Date: Thu Jan 26 2017 - 12:19:21 EST

On Wed, Jan 25, 2017 at 9:33 AM, Joao Martins <joao.m.martins@xxxxxxxxxx> wrote:
> In order to support pvclock vdso on xen we need to setup the time
> info page for vcpu 0 and register the page with Xen using the
> VCPUOP_register_vcpu_time_memory_area hypercall. This hypercall
> will also forcefully update the pvti which will set some of the
> necessary flags for vdso. Afterwards we check if it supports the
> PVCLOCK_TSC_STABLE_BIT flag which is mandatory for having
> vdso/vsyscall support. And if so, it will set the cpu 0 pvti that
> will be later on used when mapping the vdso image.
> The xen headers are also updated to include the new hypercall for
> registering the secondary vcpu_time_info struct.

No objections from me assuming the code is correct.