From: Jan Beulich <jbeulich@suse.com>
Date: Thu, 12 Nov 2015 16:02:35 +0000 (+0100)
Subject: x86: #PF error code adjustments
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=0b52ed063d6731b53eaf976cfa9c51906e50e370;p=people%2Fjulieng%2Fxen-unstable.git

x86: #PF error code adjustments

Add a definition for the (for now unused) protection key related error
code bit, moving our own custom ones out of the way. In the course of
checking the uses of the latter I realized that while right now they
can only get set on their own, callers would better not depend on that
property and check just for the bit rather than matching the entire
value.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---

diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index eeb596335a..e1017b530c 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -447,7 +447,7 @@ static int hvmemul_linear_to_phys(
     }
     else if ( (pfn = paging_gva_to_gfn(curr, addr, &pfec)) == INVALID_GFN )
     {
-        if ( pfec == PFEC_page_paged || pfec == PFEC_page_shared )
+        if ( pfec & (PFEC_page_paged | PFEC_page_shared) )
             return X86EMUL_RETRY;
         hvm_inject_page_fault(pfec, addr);
         return X86EMUL_EXCEPTION;
@@ -464,7 +464,7 @@ static int hvmemul_linear_to_phys(
         /* Is it contiguous with the preceding PFNs? If not then we're done. */
         if ( (npfn == INVALID_GFN) || (npfn != (pfn + (reverse ? -i : i))) )
         {
-            if ( pfec == PFEC_page_paged || pfec == PFEC_page_shared )
+            if ( pfec & (PFEC_page_paged | PFEC_page_shared) )
                 return X86EMUL_RETRY;
             done /= bytes_per_rep;
             if ( done == 0 )
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 2ded97df40..ea982e263e 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3820,7 +3820,7 @@ static void *hvm_map_entry(unsigned long va, bool_t *writable)
      */
     pfec = PFEC_page_present;
     gfn = paging_gva_to_gfn(current, va, &pfec);
-    if ( (pfec == PFEC_page_paged) || (pfec == PFEC_page_shared) )
+    if ( pfec & (PFEC_page_paged | PFEC_page_shared) )
         goto fail;
 
     v = hvm_map_guest_frame_rw(gfn, 0, writable);
@@ -4211,9 +4211,9 @@ static enum hvm_copy_result __hvm_copy(
             gfn = paging_gva_to_gfn(curr, addr, &pfec);
             if ( gfn == INVALID_GFN )
             {
-                if ( pfec == PFEC_page_paged )
+                if ( pfec & PFEC_page_paged )
                     return HVMCOPY_gfn_paged_out;
-                if ( pfec == PFEC_page_shared )
+                if ( pfec & PFEC_page_shared )
                     return HVMCOPY_gfn_shared;
                 if ( flags & HVMCOPY_fault )
                     hvm_inject_page_fault(pfec, addr);
@@ -4326,9 +4326,9 @@ static enum hvm_copy_result __hvm_clear(paddr_t addr, int size)
         gfn = paging_gva_to_gfn(curr, addr, &pfec);
         if ( gfn == INVALID_GFN )
         {
-            if ( pfec == PFEC_page_paged )
+            if ( pfec & PFEC_page_paged )
                 return HVMCOPY_gfn_paged_out;
-            if ( pfec == PFEC_page_shared )
+            if ( pfec & PFEC_page_shared )
                 return HVMCOPY_gfn_shared;
             return HVMCOPY_bad_gva_to_gfn;
         }
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index a40c18ee0a..3f8411f89a 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -140,8 +140,10 @@
 #define PFEC_user_mode      (1U<<2)
 #define PFEC_reserved_bit   (1U<<3)
 #define PFEC_insn_fetch     (1U<<4)
-#define PFEC_page_paged     (1U<<5)
-#define PFEC_page_shared    (1U<<6)
+#define PFEC_prot_key       (1U<<5)
+/* Internally used only flags. */
+#define PFEC_page_paged     (1U<<16)
+#define PFEC_page_shared    (1U<<17)
 
 /* Other exception error code values. */
 #define X86_XEC_EXT         (_AC(1,U) << 0)