Re: [PATCH v6 3/4] x86/xen/time: setup vcpu 0 time info page

From: Boris Ostrovsky
Date: Tue Oct 03 2017 - 08:54:31 EST




On 10/03/2017 07:55 AM, Joao Martins 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.

Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Boris Ostrovsky <boris.ostrovksy@xxxxxxxxxx>