x86/vmx: Update DR7 type

Use the new vmread() accessor and shrink dr7 to it's preferred size.

No functional change.

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/arch/x86/hvm/vmx/vmx.c

@@ -926,7 +926,7 @@ static void vmx_save_dr(struct vcpu *v)
     v->arch.dr[3] = read_debugreg(3);
     v->arch.dr6   = read_debugreg(6);
     /* DR7 must be saved as it is used by vmx_restore_dr(). */
-    __vmread(GUEST_DR7, &v->arch.dr7);
+    v->arch.dr7   = vmread(GUEST_DR7);
 }
 
 static void __restore_debug_registers(struct vcpu *v)

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

@@ -595,8 +595,8 @@ struct arch_vcpu
 
     /* Debug registers. */
     unsigned long dr[4];
-    unsigned long dr7; /* Ideally int, but __vmread() needs long. */
     unsigned int dr6;
+    unsigned int dr7;
 
     /* other state */