Despite being vaguely aware, the difference between PAGE_HYPERVISOR in ASM and
C code has nevertheless caused several bugs I should have known better about,
and contributed to review confusion.
There are exactly 4 uses of these constants in asm code (and one is shortly
going to disappear).
Instead of creating the constants which behave differently between ASM and C
code, expose all the constants and use non-ambiguous non-NX ones in ASM.
Adjust the hiding to just _PAGE_NX, which contains a C ternary expression.
Signed-off-by: Andrew Cooper
---
CC: Jan Beulich
CC: Wei Liu
CC: Roger Pau Monné
v2:
* Hide _PAGE_NX
---
xen/arch/x86/boot/head.S | 2 +-
xen/arch/x86/boot/x86_64.S| 6 +++---
xen/include/asm-x86/page.h| 4
xen/include/asm-x86/x86_64/page.h | 17 +
4 files changed, 13 insertions(+), 16 deletions(-)
diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index d246e374f1..563bb19056 100644
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -674,7 +674,7 @@ trampoline_setup:
* the transition into long mode), using 2M superpages.
*/
lea sym_esi(start),%ebx
-lea
(1<= 0xa0 && pfn < 0xc0
-.quad (pfn << PAGE_SHIFT) | PAGE_HYPERVISOR_UCMINUS | MAP_SMALL_PAGES
+.quad (pfn << PAGE_SHIFT) | __PAGE_HYPERVISOR_UCMINUS | _PAGE_GLOBAL |
MAP_SMALL_PAGES
.else
-.quad (pfn << PAGE_SHIFT) | PAGE_HYPERVISOR | MAP_SMALL_PAGES
+.quad (pfn << PAGE_SHIFT) | PAGE_HYPERVISOR_RWX | MAP_SMALL_PAGES
.endif
pfn = pfn + 1
.endr
@@ -89,7 +89,7 @@ GLOBAL(l2_xenmap)
.quad 0
idx = 1
.rept 7
-.quad sym_offs(__image_base__) + (idx << L2_PAGETABLE_SHIFT) +
(PAGE_HYPERVISOR | _PAGE_PSE)
+.quad sym_offs(__image_base__) + (idx << L2_PAGETABLE_SHIFT) +
(PAGE_HYPERVISOR_RWX | _PAGE_PSE)
idx = idx + 1
.endr
.fill L2_PAGETABLE_ENTRIES - 8, 8, 0
diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h
index 05a8b1efa6..a3c76a403b 100644
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -316,7 +316,11 @@ void efi_update_l4_pgtable(unsigned int l4idx,
l4_pgentry_t);
#define _PAGE_AVAIL_AC(0xE00,U)
#define _PAGE_PSE_PAT _AC(0x1000,U)
#define _PAGE_AVAIL_HIGH (_AC(0x7ff, U) << 12)
+
+#ifndef __ASSEMBLY__
+/* Dependency on NX being available can't be expressed. */
#define _PAGE_NX (cpu_has_nx ? _PAGE_NX_BIT : 0)
+#endif
#define PAGE_CACHE_ATTRS (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT)
diff --git a/xen/include/asm-x86/x86_64/page.h
b/xen/include/asm-x86/x86_64/page.h
index 4fe0205553..9876634881 100644
--- a/xen/include/asm-x86/x86_64/page.h
+++ b/xen/include/asm-x86/x86_64/page.h
@@ -172,18 +172,11 @@ static inline intpte_t put_pte_flags(unsigned int x)
#define PAGE_HYPERVISOR_RX (__PAGE_HYPERVISOR_RX | _PAGE_GLOBAL)
#define PAGE_HYPERVISOR_RWX (__PAGE_HYPERVISOR | _PAGE_GLOBAL)
-#ifdef __ASSEMBLY__
-/* Dependency on NX being available can't be expressed. */
-# define PAGE_HYPERVISOR PAGE_HYPERVISOR_RWX
-# define PAGE_HYPERVISOR_UCMINUS (__PAGE_HYPERVISOR_UCMINUS | _PAGE_GLOBAL)
-# define PAGE_HYPERVISOR_UC (__PAGE_HYPERVISOR_UC | _PAGE_GLOBAL)
-#else
-# define PAGE_HYPERVISOR PAGE_HYPERVISOR_RW
-# define PAGE_HYPERVISOR_UCMINUS (__PAGE_HYPERVISOR_UCMINUS | \
- _PAGE_GLOBAL | _PAGE_NX)
-# define PAGE_HYPERVISOR_UC (__PAGE_HYPERVISOR_UC | \
- _PAGE_GLOBAL | _PAGE_NX)
-#endif
+#define PAGE_HYPERVISOR PAGE_HYPERVISOR_RW
+#define PAGE_HYPERVISOR_UCMINUS (__PAGE_HYPERVISOR_UCMINUS | \
+ _PAGE_GLOBAL | _PAGE_NX)
+#define PAGE_HYPERVISOR_UC (__PAGE_HYPERVISOR_UC | \
+ _PAGE_GLOBAL | _PAGE_NX)
#endif /* __X86_64_PAGE_H__ */
--
2.11.0
___
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
