slightly reduce vm_assist code

- drop an effectively unused struct pv_vcpu field (x86)
- adjust VM_ASSIST() to prepend VMASST_TYPE_

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -901,7 +901,6 @@ int arch_set_info_guest(
         v->arch.pv_vcpu.event_callback_cs = c(event_callback_cs);
         v->arch.pv_vcpu.failsafe_callback_cs = c(failsafe_callback_cs);
     }
-    v->arch.pv_vcpu.vm_assist = c(vm_assist);
 
     /* Only CR0.TS is modifiable by guest or admin. */
     v->arch.pv_vcpu.ctrlreg[0] &= X86_CR0_TS;
@@ -973,7 +972,7 @@ int arch_set_info_guest(
         case -ERESTART:
             break;
         case 0:
-            if ( !compat && !VM_ASSIST(d, VMASST_TYPE_m2p_strict) &&
+            if ( !compat && !VM_ASSIST(d, m2p_strict) &&
                  !paging_mode_refcounts(d) )
             {
                 l4_pgentry_t *l4tab = __map_domain_page(cr3_page);
@@ -1023,7 +1022,7 @@ int arch_set_info_guest(
                         cr3_page = NULL;
                     break;
                 case 0:
-                    if ( VM_ASSIST(d, VMASST_TYPE_m2p_strict) )
+                    if ( VM_ASSIST(d, m2p_strict) )
                     {
                         l4_pgentry_t *l4tab = __map_domain_page(cr3_page);
 
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -1436,7 +1436,6 @@ void arch_get_info_guest(struct vcpu *v,
             c(event_callback_cs = v->arch.pv_vcpu.event_callback_cs);
             c(failsafe_callback_cs = v->arch.pv_vcpu.failsafe_callback_cs);
         }
-        c(vm_assist = v->arch.pv_vcpu.vm_assist);
 
         /* IOPL privileges are virtualised: merge back into returned eflags. */
         BUG_ON((c(user_regs.eflags) & X86_EFLAGS_IOPL) != 0);
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -1454,7 +1454,7 @@ static int alloc_l4_table(struct page_in
         adjust_guest_l4e(pl4e[i], d);
     }
 
-    init_guest_l4_table(pl4e, d, !VM_ASSIST(d, VMASST_TYPE_m2p_strict));
+    init_guest_l4_table(pl4e, d, !VM_ASSIST(d, m2p_strict));
     unmap_domain_page(pl4e);
 
     return rc > 0 ? 0 : rc;
@@ -2765,7 +2765,7 @@ int new_guest_cr3(unsigned long mfn)
 
     invalidate_shadow_ldt(curr, 0);
 
-    if ( !VM_ASSIST(d, VMASST_TYPE_m2p_strict) && !paging_mode_refcounts(d) )
+    if ( !VM_ASSIST(d, m2p_strict) && !paging_mode_refcounts(d) )
     {
         l4_pgentry_t *l4tab = map_domain_page(mfn);
 
@@ -3135,8 +3135,7 @@ long do_mmuext_op(
                                 op.arg1.mfn);
                     break;
                 }
-                if ( VM_ASSIST(d, VMASST_TYPE_m2p_strict) &&
-                     !paging_mode_refcounts(d) )
+                if ( VM_ASSIST(d, m2p_strict) && !paging_mode_refcounts(d) )
                 {
                     l4_pgentry_t *l4tab = map_domain_page(op.arg1.mfn);
 
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -1436,7 +1436,7 @@ void sh_install_xen_entries_in_l4(struct
         shadow_l4e_from_mfn(page_to_mfn(d->arch.perdomain_l3_pg),
                             __PAGE_HYPERVISOR);
 
-    if ( !VM_ASSIST(d, VMASST_TYPE_m2p_strict) )
+    if ( !VM_ASSIST(d, m2p_strict) )
         sl4e[shadow_l4_table_offset(RO_MPT_VIRT_START)] = shadow_l4e_empty();
 
     /* Shadow linear mapping for 4-level shadows.  N.B. for 3-level
@@ -3983,11 +3983,11 @@ sh_update_cr3(struct vcpu *v, int do_loc
             shadow_l4e_t *sl4e = v->arch.paging.shadow.guest_vtable;
 
             if ( (v->arch.flags & TF_kernel_mode) &&
-                 !VM_ASSIST(d, VMASST_TYPE_m2p_strict) )
+                 !VM_ASSIST(d, m2p_strict) )
                 sl4e[shadow_l4_table_offset(RO_MPT_VIRT_START)] =
                     idle_pg_table[l4_table_offset(RO_MPT_VIRT_START)];
             else if ( !(v->arch.flags & TF_kernel_mode) &&
-                      VM_ASSIST(d, VMASST_TYPE_m2p_strict) )
+                      VM_ASSIST(d, m2p_strict) )
                 sl4e[shadow_l4_table_offset(RO_MPT_VIRT_START)] =
                     shadow_l4e_empty();
         }
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1441,7 +1441,7 @@ static int fixup_page_fault(unsigned lon
          !(regs->error_code & (PFEC_reserved_bit | PFEC_insn_fetch)) &&
          (regs->error_code & PFEC_write_access) )
     {
-        if ( VM_ASSIST(d, VMASST_TYPE_writable_pagetables) &&
+        if ( VM_ASSIST(d, writable_pagetables) &&
              /* Do not check if access-protection fault since the page may
                 legitimately be not present in shadow page tables */
              (paging_mode_enabled(d) ||
--- a/xen/common/kernel.c
+++ b/xen/common/kernel.c
@@ -306,7 +306,7 @@ DO(xen_version)(int cmd, XEN_GUEST_HANDL
         {
         case 0:
             fi.submap = (1U << XENFEAT_memory_op_vnode_supported);
-            if ( VM_ASSIST(d, VMASST_TYPE_pae_extended_cr3) )
+            if ( VM_ASSIST(d, pae_extended_cr3) )
                 fi.submap |= (1U << XENFEAT_pae_pgdir_above_4gb);
             if ( paging_mode_translate(d) )
                 fi.submap |= 
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -372,8 +372,6 @@ struct pv_vcpu
         };
     };
 
-    unsigned long vm_assist;
-
     unsigned long syscall32_callback_eip;
     unsigned long sysenter_callback_eip;
     unsigned short syscall32_callback_cs;
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -833,7 +833,7 @@ void watchdog_domain_destroy(struct doma
 /* This check is for functionality specific to a control domain */
 #define is_control_domain(_d) ((_d)->is_privileged)
 
-#define VM_ASSIST(_d,_t) (test_bit((_t), &(_d)->vm_assist))
+#define VM_ASSIST(d, t) (test_bit(VMASST_TYPE_ ## t, &(d)->vm_assist))
 
 #define is_pv_domain(d) ((d)->guest_type == guest_type_pv)
 #define is_pv_vcpu(v)   (is_pv_domain((v)->domain))