x86/svm: Don't use vmcb->tlb_control as if it is a boolean

svm_asid_handle_vmrun() treats tlb_control as if it were boolean, but this has
been superseded by new additions to the SVM spec.

Introduce an enum containing all legal values, and update
svm_asid_handle_vmrun() to use appropriate constants.

While adjusting this, take the opportunity to fix up two coding style issues,
and trim the include list.

No functional change.

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

xen/arch/x86/hvm/svm/asid.c

@@ -15,12 +15,9 @@
  * this program; If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <xen/init.h>
-#include <xen/lib.h>
-#include <xen/perfc.h>
-#include <asm/hvm/svm/asid.h>
 #include <asm/amd.h>
 #include <asm/hvm/nestedhvm.h>
+#include <asm/hvm/svm/asid.h>
 
 void svm_asid_init(const struct cpuinfo_x86 *c)
 {
@@ -44,19 +41,21 @@ void svm_asid_handle_vmrun(void)
     struct hvm_vcpu_asid *p_asid =
         nestedhvm_vcpu_in_guestmode(curr)
         ? &vcpu_nestedhvm(curr).nv_n2asid : &curr->arch.hvm.n1asid;
-    bool_t need_flush = hvm_asid_handle_vmenter(p_asid);
+    bool need_flush = hvm_asid_handle_vmenter(p_asid);
 
     /* ASID 0 indicates that ASIDs are disabled. */
     if ( p_asid->asid == 0 )
     {
         vmcb_set_guest_asid(vmcb, 1);
-        vmcb->tlb_control = 1;
+        /* TODO: investigate using TLB_CTRL_FLUSH_ASID here instead. */
+        vmcb->tlb_control = TLB_CTRL_FLUSH_ALL;
         return;
     }
 
-    if (vmcb_get_guest_asid(vmcb) != p_asid->asid)
+    if ( vmcb_get_guest_asid(vmcb) != p_asid->asid )
         vmcb_set_guest_asid(vmcb, p_asid->asid);
-    vmcb->tlb_control = need_flush;
+
+    vmcb->tlb_control = need_flush ? TLB_CTRL_FLUSH_ALL : TLB_CTRL_NO_FLUSH;
 }
 
 /*

xen/include/asm-x86/hvm/svm/vmcb.h

@@ -302,6 +302,17 @@ enum VMEXIT_EXITCODE
     VMEXIT_INVALID          =  -1
 };
 
+enum
+{
+    /* Available on all SVM-capable hardware. */
+    TLB_CTRL_NO_FLUSH             = 0,
+    TLB_CTRL_FLUSH_ALL            = 1,
+
+    /* Available with the FlushByASID feature. */
+    TLB_CTRL_FLUSH_ASID           = 3,
+    TLB_CTRL_FLUSH_ASID_NONGLOBAL = 7,
+};
+
 typedef union
 {
     struct
@@ -419,7 +430,7 @@ struct vmcb_struct {
     u64 _msrpm_base_pa;         /* offset 0x48 - cleanbit 1 */
     u64 _tsc_offset;            /* offset 0x50 - cleanbit 0 */
     u32 _guest_asid;            /* offset 0x58 - cleanbit 2 */
-    u8  tlb_control;            /* offset 0x5C */
+    u8  tlb_control;            /* offset 0x5C - TLB_CTRL_* */
     u8  res07[3];
     vintr_t _vintr;             /* offset 0x60 - cleanbit 3 */
     intstat_t int_stat;         /* offset 0x68 */