[PATCH v3 8/8] x86: only generate compat headers actually needed

[Jan Beulich <jbeulich@xxxxxxxx>]

As was already the case for XSM/Flask, avoid generating compat headers
when they're not going to be needed. To address resulting build issues
- move compat/hvm/dm_op.h inclusion to the only source file needing it,
- add a little bit of #ifdef-ary.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Alternatively we could consistently drop conditionals (except for per-
arch cases perhaps).

--- a/xen/arch/x86/hvm/dm.c
+++ b/xen/arch/x86/hvm/dm.c
@@ -717,6 +717,8 @@ static int dm_op(const struct dmop_args
     return rc;
 }
 
+#include <compat/hvm/dm_op.h>
+
 CHECK_dm_op_create_ioreq_server;
 CHECK_dm_op_get_ioreq_server_info;
 CHECK_dm_op_ioreq_server_range;
--- a/xen/common/compat/domain.c
+++ b/xen/common/compat/domain.c
@@ -11,7 +11,6 @@ EMIT_FILE;
 #include <xen/guest_access.h>
 #include <xen/hypercall.h>
 #include <compat/vcpu.h>
-#include <compat/hvm/hvm_vcpu.h>
 
 #define xen_vcpu_set_periodic_timer vcpu_set_periodic_timer
 CHECK_vcpu_set_periodic_timer;
@@ -25,6 +24,10 @@ CHECK_SIZE_(struct, vcpu_info);
 CHECK_vcpu_register_vcpu_info;
 #undef xen_vcpu_register_vcpu_info
 
+#ifdef CONFIG_HVM
+
+#include <compat/hvm/hvm_vcpu.h>
+
 #define xen_vcpu_hvm_context vcpu_hvm_context
 #define xen_vcpu_hvm_x86_32 vcpu_hvm_x86_32
 #define xen_vcpu_hvm_x86_64 vcpu_hvm_x86_64
@@ -33,6 +36,8 @@ CHECK_vcpu_hvm_context;
 #undef xen_vcpu_hvm_x86_32
 #undef xen_vcpu_hvm_context
 
+#endif
+
 int compat_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) 
arg)
 {
     struct domain *d = current->domain;
@@ -49,6 +54,7 @@ int compat_vcpu_op(int cmd, unsigned int
         if ( v->vcpu_info == &dummy_vcpu_info )
             return -EINVAL;
 
+#ifdef CONFIG_HVM
         if ( is_hvm_vcpu(v) )
         {
             struct vcpu_hvm_context ctxt;
@@ -61,6 +67,7 @@ int compat_vcpu_op(int cmd, unsigned int
             domain_unlock(d);
         }
         else
+#endif
         {
             struct compat_vcpu_guest_context *ctxt;
 
--- a/xen/include/Makefile
+++ b/xen/include/Makefile
@@ -3,32 +3,34 @@ ifneq ($(CONFIG_COMPAT),)
 compat-arch-$(CONFIG_X86) := x86_32
 
 headers-y := \
-    compat/argo.h \
-    compat/callback.h \
+    compat/arch-$(compat-arch-y).h \
     compat/elfnote.h \
     compat/event_channel.h \
     compat/features.h \
-    compat/grant_table.h \
-    compat/hypfs.h \
-    compat/kexec.h \
     compat/memory.h \
     compat/nmi.h \
     compat/physdev.h \
     compat/platform.h \
+    compat/pmu.h \
     compat/sched.h \
-    compat/trace.h \
     compat/vcpu.h \
     compat/version.h \
     compat/xen.h \
-    compat/xenoprof.h
+    compat/xlat.h
 headers-$(CONFIG_X86)     += compat/arch-x86/pmu.h
 headers-$(CONFIG_X86)     += compat/arch-x86/xen-mca.h
 headers-$(CONFIG_X86)     += compat/arch-x86/xen.h
 headers-$(CONFIG_X86)     += compat/arch-x86/xen-$(compat-arch-y).h
-headers-$(CONFIG_X86)     += compat/hvm/dm_op.h
-headers-$(CONFIG_X86)     += compat/hvm/hvm_op.h
-headers-$(CONFIG_X86)     += compat/hvm/hvm_vcpu.h
-headers-y                 += compat/arch-$(compat-arch-y).h compat/pmu.h 
compat/xlat.h
+headers-$(CONFIG_ARGO)    += compat/argo.h
+headers-$(CONFIG_PV)      += compat/callback.h
+headers-$(CONFIG_GRANT_TABLE) += compat/grant_table.h
+headers-$(CONFIG_HVM)     += compat/hvm/dm_op.h
+headers-$(CONFIG_HVM)     += compat/hvm/hvm_op.h
+headers-$(CONFIG_HVM)     += compat/hvm/hvm_vcpu.h
+headers-$(CONFIG_HYPFS)   += compat/hypfs.h
+headers-$(CONFIG_KEXEC)   += compat/kexec.h
+headers-$(CONFIG_TRACEBUFFER) += compat/trace.h
+headers-$(CONFIG_XENOPROF) += compat/xenoprof.h
 headers-$(CONFIG_XSM_FLASK) += compat/xsm/flask_op.h
 
 cppflags-y                := -include public/xen-compat.h 
-DXEN_GENERATING_COMPAT_HEADERS
--- a/xen/include/xen/hypercall.h
+++ b/xen/include/xen/hypercall.h
@@ -216,8 +216,6 @@ extern long compat_argo_op(
     unsigned long arg4);
 #endif
 
-#include <compat/hvm/dm_op.h>
-
 extern int
 compat_dm_op(
     domid_t domid,