x86/acrn: Introduce hypercall interfaces

The Service VM communicates with the hypervisor via conventional
hypercalls. VMCALL instruction is used to make the hypercalls.

ACRN hypercall ABI:
  * Hypercall number is in R8 register.
  * Up to 2 parameters are in RDI and RSI registers.
  * Return value is in RAX register.

Introduce the ACRN hypercall interfaces. Because GCC doesn't support R8
register as direct register constraints, use supported constraint as
input with a explicit MOV to R8 in beginning of asm.

Cc: Dave Hansen <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Fengwei Yin <[email protected]>
Cc: Zhi Wang <[email protected]>
Cc: Zhenyu Wang <[email protected]>
Cc: Yu Wang <[email protected]>
Cc: Reinette Chatre <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Arvind Sankar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Segher Boessenkool <[email protected]>
Originally-by: Yakui Zhao <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Acked-by: Borislav Petkov <[email protected]>
Signed-off-by: Shuo Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

0 files changed, 0 insertions, 0 deletions