x86/xen/time: setup vcpu 0 time info page

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@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
This commit is contained in:
Joao Martins 2017-11-08 17:19:57 +00:00 committed by Boris Ostrovsky
parent b888808093
commit 2229f70b5b
4 changed files with 137 additions and 1 deletions

View file

@ -178,4 +178,46 @@ DEFINE_GUEST_HANDLE_STRUCT(vcpu_register_vcpu_info);
/* Send an NMI to the specified VCPU. @extra_arg == NULL. */
#define VCPUOP_send_nmi 11
/*
* Get the physical ID information for a pinned vcpu's underlying physical
* processor. The physical ID informmation is architecture-specific.
* On x86: id[31:0]=apic_id, id[63:32]=acpi_id.
* This command returns -EINVAL if it is not a valid operation for this VCPU.
*/
#define VCPUOP_get_physid 12 /* arg == vcpu_get_physid_t */
struct vcpu_get_physid {
uint64_t phys_id;
};
DEFINE_GUEST_HANDLE_STRUCT(vcpu_get_physid);
#define xen_vcpu_physid_to_x86_apicid(physid) ((uint32_t)(physid))
#define xen_vcpu_physid_to_x86_acpiid(physid) ((uint32_t)((physid) >> 32))
/*
* Register a memory location to get a secondary copy of the vcpu time
* parameters. The master copy still exists as part of the vcpu shared
* memory area, and this secondary copy is updated whenever the master copy
* is updated (and using the same versioning scheme for synchronisation).
*
* The intent is that this copy may be mapped (RO) into userspace so
* that usermode can compute system time using the time info and the
* tsc. Usermode will see an array of vcpu_time_info structures, one
* for each vcpu, and choose the right one by an existing mechanism
* which allows it to get the current vcpu number (such as via a
* segment limit). It can then apply the normal algorithm to compute
* system time from the tsc.
*
* @extra_arg == pointer to vcpu_register_time_info_memory_area structure.
*/
#define VCPUOP_register_vcpu_time_memory_area 13
DEFINE_GUEST_HANDLE_STRUCT(vcpu_time_info);
struct vcpu_register_time_memory_area {
union {
GUEST_HANDLE(vcpu_time_info) h;
struct pvclock_vcpu_time_info *v;
uint64_t p;
} addr;
};
DEFINE_GUEST_HANDLE_STRUCT(vcpu_register_time_memory_area);
#endif /* __XEN_PUBLIC_VCPU_H__ */