xen/x86: add some cr3 helpers

Add some helper macros to access the address and pcid parts of cr3.

Use those helpers where appropriate.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/debug.c

@@ -98,7 +98,7 @@ dbg_pv_va2mfn(dbgva_t vaddr, struct domain *dp, uint64_t pgd3val)
     l2_pgentry_t l2e, *l2t;
     l1_pgentry_t l1e, *l1t;
     unsigned long cr3 = (pgd3val ? pgd3val : dp->vcpu[0]->arch.cr3);
-    mfn_t mfn = maddr_to_mfn(cr3);
+    mfn_t mfn = maddr_to_mfn(cr3_pa(cr3));
 
     DBGP2("vaddr:%lx domid:%d cr3:%lx pgd3:%lx\n", vaddr, dp->domain_id, 
           cr3, pgd3val);

xen/arch/x86/domain_page.c

@@ -51,7 +51,7 @@ static inline struct vcpu *mapcache_current_vcpu(void)
         if ( (v = idle_vcpu[smp_processor_id()]) == current )
             sync_local_execstate();
         /* We must now be running on the idle page table. */
-        ASSERT(read_cr3() == __pa(idle_pg_table));
+        ASSERT(cr3_pa(read_cr3()) == __pa(idle_pg_table));
     }
 
     return v;

xen/include/asm-x86/processor.h

@@ -288,6 +288,16 @@ static inline void write_cr3(unsigned long val)
     asm volatile ( "mov %0, %%cr3" : : "r" (val) : "memory" );
 }
 
+static inline unsigned long cr3_pa(unsigned long cr3)
+{
+    return cr3 & X86_CR3_ADDR_MASK;
+}
+
+static inline unsigned long cr3_pcid(unsigned long cr3)
+{
+    return cr3 & X86_CR3_PCID_MASK;
+}
+
 static inline unsigned long read_cr4(void)
 {
     return get_cpu_info()->cr4;

xen/include/asm-x86/x86-defns.h

@@ -45,7 +45,9 @@
 /*
  * Intel CPU flags in CR3
  */
-#define X86_CR3_NOFLUSH (_AC(1, ULL) << 63)
+#define X86_CR3_NOFLUSH    (_AC(1, ULL) << 63)
+#define X86_CR3_ADDR_MASK  (PAGE_MASK & PADDR_MASK)
+#define X86_CR3_PCID_MASK  _AC(0x0fff, ULL) /* Mask for PCID */
 
 /*
  * Intel CPU features in CR4