xen: move do_vcpu_op() to arch specific code

The entry point used for the vcpu_op hypercall on Arm is different
from the one on x86 today, as some of the common sub-ops are not
supported on Arm. The Arm specific handler filters out the not
supported sub-ops and then calls the common handler. This leads to the
weird call hierarchy:

  do_arm_vcpu_op()
    do_vcpu_op()
      arch_do_vcpu_op()

Clean this up by renaming do_vcpu_op() to common_vcpu_op() and
arch_do_vcpu_op() in each architecture to do_vcpu_op(). This way one
of above calls can be avoided without restricting any potential
future use of common sub-ops for Arm.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Roger Pau Monné <roger.pau@cirtrix.com>

xen/arch/arm/domain.c

@@ -1079,23 +1079,24 @@ void arch_dump_domain_info(struct domain *d)
 }
 
 
-long do_arm_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
+long do_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
+    struct domain *d = current->domain;
+    struct vcpu *v;
+
+    if ( (v = domain_vcpu(d, vcpuid)) == NULL )
+        return -ENOENT;
+
     switch ( cmd )
     {
         case VCPUOP_register_vcpu_info:
         case VCPUOP_register_runstate_memory_area:
-            return do_vcpu_op(cmd, vcpuid, arg);
+            return common_vcpu_op(cmd, v, arg);
         default:
             return -EINVAL;
     }
 }
 
-long arch_do_vcpu_op(int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg)
-{
-    return -ENOSYS;
-}
-
 void arch_dump_vcpu_info(struct vcpu *v)
 {
     gic_dump_info(v);

xen/arch/arm/include/asm/hypercall.h

@@ -8,8 +8,6 @@
 #include <public/domctl.h> /* for arch_do_domctl */
 int do_arm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg);
 
-long do_arm_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg);
-
 long subarch_do_domctl(struct xen_domctl *domctl, struct domain *d,
                        XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl);
 

xen/arch/arm/traps.c

@@ -1380,7 +1380,7 @@ static arm_hypercall_t arm_hypercall_table[] = {
 #endif
     HYPERCALL(multicall, 2),
     HYPERCALL(platform_op, 1),
-    HYPERCALL_ARM(vcpu_op, 3),
+    HYPERCALL(vcpu_op, 3),
     HYPERCALL(vm_assist, 2),
 #ifdef CONFIG_ARGO
     HYPERCALL(argo_op, 5),

xen/arch/x86/domain.c

@@ -1491,11 +1491,15 @@ int arch_vcpu_reset(struct vcpu *v)
     return 0;
 }
 
-long
-arch_do_vcpu_op(
-    int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg)
+long cf_check do_vcpu_op(int cmd, unsigned int vcpuid,
+                         XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     long rc = 0;
+    struct domain *d = current->domain;
+    struct vcpu *v;
+
+    if ( (v = domain_vcpu(d, vcpuid)) == NULL )
+        return -ENOENT;
 
     switch ( cmd )
     {
@@ -1547,7 +1551,7 @@ arch_do_vcpu_op(
     }
 
     default:
-        rc = -ENOSYS;
+        rc = common_vcpu_op(cmd, v, arg);
         break;
     }
 

xen/arch/x86/include/asm/hypercall.h

@@ -149,7 +149,7 @@ compat_physdev_op(
     XEN_GUEST_HANDLE_PARAM(void) arg);
 
 extern int
-arch_compat_vcpu_op(
+compat_common_vcpu_op(
     int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg);
 
 extern int cf_check compat_mmuext_op(

xen/arch/x86/x86_64/domain.c

@@ -12,11 +12,15 @@
 CHECK_vcpu_get_physid;
 #undef xen_vcpu_get_physid
 
-int
-arch_compat_vcpu_op(
-    int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg)
+int cf_check
+compat_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    int rc = -ENOSYS;
+    int rc;
+    struct domain *d = current->domain;
+    struct vcpu *v;
+
+    if ( (v = domain_vcpu(d, vcpuid)) == NULL )
+        return -ENOENT;
 
     switch ( cmd )
     {
@@ -55,7 +59,11 @@ arch_compat_vcpu_op(
     }
 
     case VCPUOP_get_physid:
-        rc = arch_do_vcpu_op(cmd, v, arg);
+        rc = do_vcpu_op(cmd, vcpuid, arg);
+        break;
+
+    default:
+        rc = compat_common_vcpu_op(cmd, v, arg);
         break;
     }
 

xen/common/compat/domain.c

@@ -38,15 +38,12 @@ CHECK_vcpu_hvm_context;
 
 #endif
 
-int cf_check compat_vcpu_op(
-    int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
+int compat_common_vcpu_op(int cmd, struct vcpu *v,
+                          XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    struct domain *d = current->domain;
-    struct vcpu *v;
     int rc = 0;
-
-    if ( (v = domain_vcpu(d, vcpuid)) == NULL )
-        return -ENOENT;
+    struct domain *d = current->domain;
+    unsigned int vcpuid = v->vcpu_id;
 
     switch ( cmd )
     {
@@ -103,7 +100,7 @@ int cf_check compat_vcpu_op(
     case VCPUOP_stop_singleshot_timer:
     case VCPUOP_register_vcpu_info:
     case VCPUOP_send_nmi:
-        rc = do_vcpu_op(cmd, vcpuid, arg);
+        rc = common_vcpu_op(cmd, v, arg);
         break;
 
     case VCPUOP_get_runstate_info:
@@ -134,7 +131,7 @@ int cf_check compat_vcpu_op(
     }
 
     default:
-        rc = arch_compat_vcpu_op(cmd, v, arg);
+        rc = -ENOSYS;
         break;
     }
 

xen/common/domain.c

@@ -1569,15 +1569,11 @@ int default_initialise_vcpu(struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg)
     return rc;
 }
 
-long cf_check do_vcpu_op(
-    int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg)
+long common_vcpu_op(int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    struct domain *d = current->domain;
-    struct vcpu *v;
     long rc = 0;
-
-    if ( (v = domain_vcpu(d, vcpuid)) == NULL )
-        return -ENOENT;
+    struct domain *d = v->domain;
+    unsigned int vcpuid = v->vcpu_id;
 
     switch ( cmd )
     {
@@ -1749,7 +1745,7 @@ long cf_check do_vcpu_op(
     }
 
     default:
-        rc = arch_do_vcpu_op(cmd, v, arg);
+        rc = -ENOSYS;
         break;
     }
 

xen/include/xen/hypercall.h

@@ -110,7 +110,7 @@ do_vcpu_op(
 
 struct vcpu;
 extern long
-arch_do_vcpu_op(int cmd,
+common_vcpu_op(int cmd,
     struct vcpu *v,
     XEN_GUEST_HANDLE_PARAM(void) arg);