x86/hvm: Revert per-domain APIC acceleration support

I was really hoping to avoid this, but its now too late in the 4.17 freeze and
we still don't have working fixes.

The in-Xen calculations for assistance capabilities are buggy.  For the
avoidance of doubt, the original intention was to be able to control every
aspect of a APIC acceleration so we could comprehensively test Xen's support,
as it has proved to be buggy time and time again.

Even after a protracted discussion on what the new API ought to mean, attempts
to apply it to the existing logic have been unsuccessful, proving that the
API/ABI is too complicated for most people to reason about.

This reverts most of:
  2ce11ce249
  6b2b9b3405

leaving in place the non-APIC specific changes (minimal as they are).

This takes us back to the behaviour of Xen 4.16 where APIC acceleration is
configured on a per system basis.

This work will be revisted in due course.

Fixes: 2ce11ce249 ("x86/HVM: allow per-domain usage of hardware virtualized APIC")
Fixes: 6b2b9b3405 ("x86: report Interrupt Controller Virtualization capabilities")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>

tools/golang/xenlight/helpers.gen.go

@@ -1120,12 +1120,6 @@ x.ArchArm.Vuart = VuartType(xc.arch_arm.vuart)
 if err := x.ArchX86.MsrRelaxed.fromC(&xc.arch_x86.msr_relaxed);err != nil {
 return fmt.Errorf("converting field ArchX86.MsrRelaxed: %v", err)
 }
-if err := x.ArchX86.AssistedXapic.fromC(&xc.arch_x86.assisted_xapic);err != nil {
-return fmt.Errorf("converting field ArchX86.AssistedXapic: %v", err)
-}
-if err := x.ArchX86.AssistedX2Apic.fromC(&xc.arch_x86.assisted_x2apic);err != nil {
-return fmt.Errorf("converting field ArchX86.AssistedX2Apic: %v", err)
-}
 x.Altp2M = Altp2MMode(xc.altp2m)
 x.VmtraceBufKb = int(xc.vmtrace_buf_kb)
 if err := x.Vpmu.fromC(&xc.vpmu);err != nil {
@@ -1611,12 +1605,6 @@ xc.arch_arm.vuart = C.libxl_vuart_type(x.ArchArm.Vuart)
 if err := x.ArchX86.MsrRelaxed.toC(&xc.arch_x86.msr_relaxed); err != nil {
 return fmt.Errorf("converting field ArchX86.MsrRelaxed: %v", err)
 }
-if err := x.ArchX86.AssistedXapic.toC(&xc.arch_x86.assisted_xapic); err != nil {
-return fmt.Errorf("converting field ArchX86.AssistedXapic: %v", err)
-}
-if err := x.ArchX86.AssistedX2Apic.toC(&xc.arch_x86.assisted_x2apic); err != nil {
-return fmt.Errorf("converting field ArchX86.AssistedX2Apic: %v", err)
-}
 xc.altp2m = C.libxl_altp2m_mode(x.Altp2M)
 xc.vmtrace_buf_kb = C.int(x.VmtraceBufKb)
 if err := x.Vpmu.toC(&xc.vpmu); err != nil {
@@ -3405,8 +3393,6 @@ x.CapVmtrace = bool(xc.cap_vmtrace)
 x.CapVpmu = bool(xc.cap_vpmu)
 x.CapGnttabV1 = bool(xc.cap_gnttab_v1)
 x.CapGnttabV2 = bool(xc.cap_gnttab_v2)
-x.CapAssistedXapic = bool(xc.cap_assisted_xapic)
-x.CapAssistedX2Apic = bool(xc.cap_assisted_x2apic)
 
  return nil}
 
@@ -3441,8 +3427,6 @@ xc.cap_vmtrace = C.bool(x.CapVmtrace)
 xc.cap_vpmu = C.bool(x.CapVpmu)
 xc.cap_gnttab_v1 = C.bool(x.CapGnttabV1)
 xc.cap_gnttab_v2 = C.bool(x.CapGnttabV2)
-xc.cap_assisted_xapic = C.bool(x.CapAssistedXapic)
-xc.cap_assisted_x2apic = C.bool(x.CapAssistedX2Apic)
 
  return nil
  }

tools/golang/xenlight/types.gen.go

@@ -534,8 +534,6 @@ Vuart VuartType
 }
 ArchX86 struct {
 MsrRelaxed Defbool
-AssistedXapic Defbool
-AssistedX2Apic Defbool
 }
 Altp2M Altp2MMode
 VmtraceBufKb int
@@ -1036,8 +1034,6 @@ CapVmtrace bool
 CapVpmu bool
 CapGnttabV1 bool
 CapGnttabV2 bool
-CapAssistedXapic bool
-CapAssistedX2Apic bool
 }
 
 type Connectorinfo struct {